CAUSES OF GLOBAL WARMING
Global warming is a term used to describe a series of disruptive worldwide climate changes that threaten the stability of a variety of ecosystems, ranging from the polar ice caps to the plains of the central United States to the South American rain forests. It is generally accepted that byproducts of human life and industry are the main causes of the issue. However, it should be noted there is still debate among the scientific community about whether global warming is real.
CARBON DIOXIDE
A large cause of global warming is carbon dioxide released from human made devices. Carbon dioxide is a greenhouse gas, which means in large and unnatural amounts it can trap heat inside the atmosphere and disrupt solar light. Power plants, automobiles and airplanes are major producers of carbon dioxide. Power plants use fossil fuels, such as coal, natural gas and oil, to create electrical power, and are responsible for 40 percent of carbon dioxide emissions in the United States. Automobiles burning gasoline are responsible for around 33 percent of the country's carbon dioxide emissions, while aviation around the word accounts for between 3 percent and 15 percent.
DEFORESTATION
Carbon dioxide levels have also been affected by deforestation. Trees are natural combatants of global warming because they are able to process carbon dioxide in the atmosphere as sustenance and return it to the air as oxygen. However, the commercial destruction of the world's tree population has diminished one of the key deterrents of global warming.
METHANE
Methane is another naturally occurring greenhouse gas that has abnormally increased in amount due to human behavior. Methane is commonly released in flatulence from cows as well as from soil bacteria in rice paddies. The huge growth in both the bovine and rice industries over the past 100 years have resulted in the exponential increase in cattle farms and rice paddies, which have helped shift methane levels in the atmosphere to unheard of levels. Methane is also a byproduct of many of the techniques used to harvest and control fossil fuels.
WATER VAPOR
An increased amount of water vapor in the atmosphere has recently been identified as contributing to global warming. As greenhouse gas levels have grown and increased the mean atmospheric temperature, they have created ideal warmer temperatures for water vapor and humidity to form. Like carbon dioxide and methane, water vapor has the ability to stop heat and other gases from leaving the Earth's atmosphere, perpetuating the destructive warming cycle.
NITROUS OXIDE
nitrous oxide, also referred to as laughing gas, is a contributor to global warming that occurs both naturally and in response to human activity. it is released during the production of nitrogen based products, like nylon, fertilizers, catalytic converters and nitric acid. nitrous oxide is also released when organic matter is burned, such as leaves or wood.
Wednesday, April 8, 2009
Greenhouse gases are the ingredients of the atmosphere that add to the greenhouse effect. Some greenhouse gases are present naturally in the atmosphere, whereas few green house gases a consequence of human activity. The greenhouse gases that are present in the atmosphere naturally include water vapor, carbon dioxide, nitrous oxide, methane and ozone. There are a few human activities, which increase the levels of most of these naturally occurring gases. The concentration of various green house effect gases has substantially increased in the recent times.
Greenhouse gases, which are the major cause of global warming, trap heat in the earth's atmosphere. Since the middle of the 19th century, human agriculture and industrialization have dispensed an enormous quantity of these green house gases into the atmosphere, where these have trapped enough heat to begin climate change. According to the United Nations, there has been a rise of about 0.6 degrees Celsius during the past century. More warming is expected to occur in the coming decades
The main reasons for the emission of gases that are a cause of green house effect are burning of fossil fuel like coal in the power plants for the purpose of generation of electricity. Fossil fuel burning leads to high emissions of carbon dioxide gas. Another green house gas is methane. Methane is more than 20 times as effectual as CO2 at entrapping heat in the atmosphere.
Methane is obtained from resources such as rice paddies, bovine flatulence, bacteria in bogs and fossil fuel manufacture. Almost in all parts of the world, rice is grown on flooded fields. When fields are flooded, anaerobic situation build up and the organic matter in the soil decays, releasing methane to the atmosphere. Nitrous oxide, which is a colorless gas with a sweet odor, is also a green house gas. The main sources of nitrous oxide include nylon and nitric acid production, cars with catalytic converters, the use of fertilizers in agriculture and the burning of organic matter. A greater emission of nitrous oxides in the recent decades is leading global warming. Another jump in the category of green house gases is in the name of hydroflourocarbons and perflourocarbons, man made chemicals initiated as a substitute to other chemicals that deplete the atmosphere's protective ozone layer.
The speedy increase in greenhouse gases over the past century is a matter of worry in at least 800,000 years, according to a study of the oldest Antarctic ice core. Scientists at the British Antarctic Survey (BAS) in Cambridge have established the fact that there have been eight cycles of atmospheric alterations in the past 800,000 years when green house gases like carbon dioxide and methane have risen to high levels. Each time, the earth also had a comparatively high temperatures linked with warm; inter glacial periods, which were most certainly associated with levels of carbon dioxide and probably methane in the atmosphere. However, present levels of green house gases are much higher than everything seen during those previous warm periods.
Although much is being done to reduce the emission of these green house gases, but the efforts are still not enough. An international agreement called the Kyoto Protocol has been made among the various nations to cut down the emission of these gases. There is a dire need that each one understands the ill effects of these green house gases and does the need full.
Greenhouse gases, which are the major cause of global warming, trap heat in the earth's atmosphere. Since the middle of the 19th century, human agriculture and industrialization have dispensed an enormous quantity of these green house gases into the atmosphere, where these have trapped enough heat to begin climate change. According to the United Nations, there has been a rise of about 0.6 degrees Celsius during the past century. More warming is expected to occur in the coming decades
The main reasons for the emission of gases that are a cause of green house effect are burning of fossil fuel like coal in the power plants for the purpose of generation of electricity. Fossil fuel burning leads to high emissions of carbon dioxide gas. Another green house gas is methane. Methane is more than 20 times as effectual as CO2 at entrapping heat in the atmosphere.
Methane is obtained from resources such as rice paddies, bovine flatulence, bacteria in bogs and fossil fuel manufacture. Almost in all parts of the world, rice is grown on flooded fields. When fields are flooded, anaerobic situation build up and the organic matter in the soil decays, releasing methane to the atmosphere. Nitrous oxide, which is a colorless gas with a sweet odor, is also a green house gas. The main sources of nitrous oxide include nylon and nitric acid production, cars with catalytic converters, the use of fertilizers in agriculture and the burning of organic matter. A greater emission of nitrous oxides in the recent decades is leading global warming. Another jump in the category of green house gases is in the name of hydroflourocarbons and perflourocarbons, man made chemicals initiated as a substitute to other chemicals that deplete the atmosphere's protective ozone layer.
The speedy increase in greenhouse gases over the past century is a matter of worry in at least 800,000 years, according to a study of the oldest Antarctic ice core. Scientists at the British Antarctic Survey (BAS) in Cambridge have established the fact that there have been eight cycles of atmospheric alterations in the past 800,000 years when green house gases like carbon dioxide and methane have risen to high levels. Each time, the earth also had a comparatively high temperatures linked with warm; inter glacial periods, which were most certainly associated with levels of carbon dioxide and probably methane in the atmosphere. However, present levels of green house gases are much higher than everything seen during those previous warm periods.
Although much is being done to reduce the emission of these green house gases, but the efforts are still not enough. An international agreement called the Kyoto Protocol has been made among the various nations to cut down the emission of these gases. There is a dire need that each one understands the ill effects of these green house gases and does the need full.
Global Warming is increasing the earth’s average temperature.
The Green house gases are the main culprits of the global warming. The green house gases like carbon dioxide, methane, and nitrous oxide are playing hazards in the present times. These green house gases trap heat in earth’s atmosphere and thus result in increasing the temperature of earth. The excessive emission of these gases is the major cause of global warming.
The major source of carbon dioxide is the power plants.
These power plants emit large amounts of carbon dioxide produced from burning of fossil fuels for the purpose of electricity generation. Coal is the major fuel that is burnt in these power plants. Coal produces around 1.7 times as much carbon dioxide per unit of energy when flamed as does natural gas and 1.25 times as much as oil. The coal gives out eighty percent more carbon per unit of energy it produces as compared to natural gas. Another major source of carbon dioxide in the atmosphere is the emission from the cars and other vehicles. About twenty percent of carbon dioxide emitted in the atmosphere comes from burning of gasoline in the engines of the vehicles. This is true for most of the developed countries. Moreover if sports bike and vehicles that are essentially designed for rough terrain, emit more carbon dioxide when used for general purpose on roads. It is always better to use vehicles designed for city driving on the city roads.
Buildings, both commercial and residential represent a larger source of global warming pollution than cars and trucks.
Building of these structures require a lot of fuel to be burnt which emits a large amount of carbon dioxide in the atmosphere.
The second major greenhouse gas after carbon dioxide, which causes global warming, is Methane.
Methane is more than 20 times as effectual as CO2 at entrapping heat in the atmosphere. Methane is obtained from resources such as rice paddies, bovine flatulence, bacteria in bogs and fossil fuel manufacture. Almost in all parts of the world, rice is grown on flooded fields. When fields are flooded, anaerobic situation build up and the organic matter in the soil decays, releasing methane to the atmosphere. Nitrous oxide, which is a colorless gas with a sweet odour, is another green house gas. The main sources of nitrous oxide include nylon and nitric acid production, cars with catalytic converters, the use of fertilizers in agriculture and the burning of organic matter. Greater emissions of nitrous oxides in the recent decades is leading global warming
Another major cause of global warming is deforestation.
Deforestation is to be blamed for 25% of all carbon dioxide release entering the atmosphere, by the cutting and burning of about 34 million acres of trees each year. Trees collect the CO2 that we breathe out and give away from various other sources, and they give back oxygen that we breathe in. Thus, cutting of trees is leading to greater concentration of carbon dioxide in the atmosphere. Greater urbanization, requirement of land for factories and buildings, requirement of timber are all reasons that are leading to deforestation, which in turn is leading to global warming.
The Green house gases are the main culprits of the global warming. The green house gases like carbon dioxide, methane, and nitrous oxide are playing hazards in the present times. These green house gases trap heat in earth’s atmosphere and thus result in increasing the temperature of earth. The excessive emission of these gases is the major cause of global warming.
The major source of carbon dioxide is the power plants.
These power plants emit large amounts of carbon dioxide produced from burning of fossil fuels for the purpose of electricity generation. Coal is the major fuel that is burnt in these power plants. Coal produces around 1.7 times as much carbon dioxide per unit of energy when flamed as does natural gas and 1.25 times as much as oil. The coal gives out eighty percent more carbon per unit of energy it produces as compared to natural gas. Another major source of carbon dioxide in the atmosphere is the emission from the cars and other vehicles. About twenty percent of carbon dioxide emitted in the atmosphere comes from burning of gasoline in the engines of the vehicles. This is true for most of the developed countries. Moreover if sports bike and vehicles that are essentially designed for rough terrain, emit more carbon dioxide when used for general purpose on roads. It is always better to use vehicles designed for city driving on the city roads.
Buildings, both commercial and residential represent a larger source of global warming pollution than cars and trucks.
Building of these structures require a lot of fuel to be burnt which emits a large amount of carbon dioxide in the atmosphere.
The second major greenhouse gas after carbon dioxide, which causes global warming, is Methane.
Methane is more than 20 times as effectual as CO2 at entrapping heat in the atmosphere. Methane is obtained from resources such as rice paddies, bovine flatulence, bacteria in bogs and fossil fuel manufacture. Almost in all parts of the world, rice is grown on flooded fields. When fields are flooded, anaerobic situation build up and the organic matter in the soil decays, releasing methane to the atmosphere. Nitrous oxide, which is a colorless gas with a sweet odour, is another green house gas. The main sources of nitrous oxide include nylon and nitric acid production, cars with catalytic converters, the use of fertilizers in agriculture and the burning of organic matter. Greater emissions of nitrous oxides in the recent decades is leading global warming
Another major cause of global warming is deforestation.
Deforestation is to be blamed for 25% of all carbon dioxide release entering the atmosphere, by the cutting and burning of about 34 million acres of trees each year. Trees collect the CO2 that we breathe out and give away from various other sources, and they give back oxygen that we breathe in. Thus, cutting of trees is leading to greater concentration of carbon dioxide in the atmosphere. Greater urbanization, requirement of land for factories and buildings, requirement of timber are all reasons that are leading to deforestation, which in turn is leading to global warming.
THE MAIN CAUSE OF GLOBAL WARMING
It took more than 20 years to broadly accept that mankind is causing global warming with the emission of greenhouse gases. The drastic increase in the emission of CO2 (carbon dioxide) within the last 30 years caused by burning fossil fuels has been identified as the major reason for the change of temperature in the atmosphere (click the following link for a summary and graphs about the cause and effects of global warming ).
More than 80% of the world-wide energy demand is currently supplied by the fossil fuels coal, oil or gas. It will be impossible to find alternative sources, which could replace fossil fuels in the short or medium term. The energy demand is simply too high.
Another issue is the non-renewable characteristic of fossil fuels: It took nature millions of years to generate these resources, however we will have used them up within the next decades. Alone the shrinking supply will not make it possible to continue as usual for a longer time.
The main cause of global warming is our treatment of Nature
· Why have warnings about climate change been ignored for more than 20 years?
· Why were ever more scientific evidence demanded to find the coherence of man-made CO2 emissions as cause of global warming? Why wasn't common sense reason enough to act?
· Why can one still today find people who stick their head in the sand and don't want to understand what's going on in the earth's atmosphere?
· Why do most people refuse to change their personal behavior voluntary in order to reduce CO2 emissions caused by their activities?
The answer to all these questions is a rather simple one:
In our technology and scientific minded world, we seem to have forgotten that mankind is only a relatively minor part of Nature. We ignore being part of a larger whole.
We believe to be able to control Nature instead of trying to arrange ourselves with Nature. This haughtiness is the true main cause of global warming. As a matter of fact, some people still believe that technical solutions alone would be sufficient to fight global warming.
Although we are guests on Earth, we behave as if no further visitors would arrive after us. It's like having a wild party where we destroy beds, the kitchen as well as the living room of a hotel without ever thinking about our future staying in the hotel nor about other guests arriving later.
In addition, our unit of measure is more and more often money only. What has no price tag, seems to have no value to us any more. In doing so we mix up economic growth with general well-being and financial income with personal happiness, respectively.
There is a loss of value behind this attitudes. We got blind for the true reason of our incarnation on earth:
We live here to train those traits , which will finally lead to perpetual harmony with ourselves and with our environment as well as to inner calm and peace.
It took more than 20 years to broadly accept that mankind is causing global warming with the emission of greenhouse gases. The drastic increase in the emission of CO2 (carbon dioxide) within the last 30 years caused by burning fossil fuels has been identified as the major reason for the change of temperature in the atmosphere (click the following link for a summary and graphs about the cause and effects of global warming ).
More than 80% of the world-wide energy demand is currently supplied by the fossil fuels coal, oil or gas. It will be impossible to find alternative sources, which could replace fossil fuels in the short or medium term. The energy demand is simply too high.
Another issue is the non-renewable characteristic of fossil fuels: It took nature millions of years to generate these resources, however we will have used them up within the next decades. Alone the shrinking supply will not make it possible to continue as usual for a longer time.
The main cause of global warming is our treatment of Nature
· Why have warnings about climate change been ignored for more than 20 years?
· Why were ever more scientific evidence demanded to find the coherence of man-made CO2 emissions as cause of global warming? Why wasn't common sense reason enough to act?
· Why can one still today find people who stick their head in the sand and don't want to understand what's going on in the earth's atmosphere?
· Why do most people refuse to change their personal behavior voluntary in order to reduce CO2 emissions caused by their activities?
The answer to all these questions is a rather simple one:
In our technology and scientific minded world, we seem to have forgotten that mankind is only a relatively minor part of Nature. We ignore being part of a larger whole.
We believe to be able to control Nature instead of trying to arrange ourselves with Nature. This haughtiness is the true main cause of global warming. As a matter of fact, some people still believe that technical solutions alone would be sufficient to fight global warming.
Although we are guests on Earth, we behave as if no further visitors would arrive after us. It's like having a wild party where we destroy beds, the kitchen as well as the living room of a hotel without ever thinking about our future staying in the hotel nor about other guests arriving later.
In addition, our unit of measure is more and more often money only. What has no price tag, seems to have no value to us any more. In doing so we mix up economic growth with general well-being and financial income with personal happiness, respectively.
There is a loss of value behind this attitudes. We got blind for the true reason of our incarnation on earth:
We live here to train those traits , which will finally lead to perpetual harmony with ourselves and with our environment as well as to inner calm and peace.
Greenhouse Effect Example
Bright sunlight will effectively warm your car on a cold, clear day by the greenhouse effect. The longer infrared wavelengths radiated by sun-warmed objects do not pass readily through the glass. The entrapment of this energy warms the interior of the vehicle. The trapping of the hot air so that it cannot rise and lose the energy by convection also plays a major role.
Short wavelengths of visible light are readily transmitted through the transparent windshield. (Otherwise you wouldn't be able to see through it!)
Shorter wavelengths of ultraviolet light are largely blocked by glass since they have greater quantum energies which have absorption mechanisms in the glass. Even though you may be uncomfortably warm with bright sunlight streaming through, you will not be sunburned.
Bright sunlight will effectively warm your car on a cold, clear day by the greenhouse effect. The longer infrared wavelengths radiated by sun-warmed objects do not pass readily through the glass. The entrapment of this energy warms the interior of the vehicle. The trapping of the hot air so that it cannot rise and lose the energy by convection also plays a major role.
Short wavelengths of visible light are readily transmitted through the transparent windshield. (Otherwise you wouldn't be able to see through it!)
Shorter wavelengths of ultraviolet light are largely blocked by glass since they have greater quantum energies which have absorption mechanisms in the glass. Even though you may be uncomfortably warm with bright sunlight streaming through, you will not be sunburned.
Greenhouse Effect
The greenhouse effect refers to circumstances where the short wavelengths of visible light from the sun pass through a transparent medium and are absorbed, but the longer wavelengths of the infrared re-radiation from the heated objects are unable to pass through that medium. The trapping of the long wavelength radiation leads to more heating and a higher resultant temperature. Besides the heating of an automobile by sunlight through the windshield and the namesake example of heating the greenhouse by sunlight passing through sealed, transparent windows, the greenhouse effect has been widely used to describe the trapping of excess heat by the rising concentration of carbon dioxide in the atmosphere. The carbon dioxide strongly absorbs infrared and does not allow as much of it to escape into space.
A major part of the efficiency of the heating of an actual greenhouse is the trapping of the air so that the energy is not lost by convection. Keeping the hot air from escaping out the top is part of the practical "greenhouse effect", but it is common usage to refer to the infrared trapping as the "greenhouse effect" in atmospheric applications where the air trapping is not applicable.
The greenhouse effect refers to circumstances where the short wavelengths of visible light from the sun pass through a transparent medium and are absorbed, but the longer wavelengths of the infrared re-radiation from the heated objects are unable to pass through that medium. The trapping of the long wavelength radiation leads to more heating and a higher resultant temperature. Besides the heating of an automobile by sunlight through the windshield and the namesake example of heating the greenhouse by sunlight passing through sealed, transparent windows, the greenhouse effect has been widely used to describe the trapping of excess heat by the rising concentration of carbon dioxide in the atmosphere. The carbon dioxide strongly absorbs infrared and does not allow as much of it to escape into space.
A major part of the efficiency of the heating of an actual greenhouse is the trapping of the air so that the energy is not lost by convection. Keeping the hot air from escaping out the top is part of the practical "greenhouse effect", but it is common usage to refer to the infrared trapping as the "greenhouse effect" in atmospheric applications where the air trapping is not applicable.
Temperature and Heat
Temperature and heat are not the same phenomenon. Temperature is a measure of the intensity or degree of hotness in a body. Technically, it is determined by getting the average speed of a body's molecules. Heat is a measure of the quantity of heat energy present in a body. The spatial distribution of temperature in a body determines heat flow. Heat always flows from warmer to colder areas.
The heat held in an object depends not only on its temperature but also its mass. For example, let us compare the heating of two different masses of water (Table 1). In this example, one mass has a weight of 5 grams, while the other is 25 grams. If the temperature of both masses is raised from 20 to 25° Celsius, the larger mass of water will require five times more heat energy for this increase in temperature. This larger mass would also contain 5 times more stored heat energy.
Temperature and heat are not the same phenomenon. Temperature is a measure of the intensity or degree of hotness in a body. Technically, it is determined by getting the average speed of a body's molecules. Heat is a measure of the quantity of heat energy present in a body. The spatial distribution of temperature in a body determines heat flow. Heat always flows from warmer to colder areas.
The heat held in an object depends not only on its temperature but also its mass. For example, let us compare the heating of two different masses of water (Table 1). In this example, one mass has a weight of 5 grams, while the other is 25 grams. If the temperature of both masses is raised from 20 to 25° Celsius, the larger mass of water will require five times more heat energy for this increase in temperature. This larger mass would also contain 5 times more stored heat energy.
Methane was on the rise for 2007. A new study by the Advanced Global Atmospheric Gases Experiment has concluded the amount of methane in Earth's atmosphere shot up in the early parts of 2007. This worldwide NASA-funded measurement network was created in the 1970s in response to international concerns about chemicals depleting the ozone layer.
The original research was published by the American Geophysical Union's Geophysical Review Letters by Matthew Rigby and Ronald Prinn of the Massachusetts Institute of Technology. In the press release on the findings, the lead authors discuss the role of methane in the atmosphere.
Methane levels have tripled since the Industrial Revolution. This is a potentially dangerous situation given that methane is about 25 times stronger as a greenhouse gas per metric ton of emissions than carbon dioxide. For nearly a decade, the amount of methane in the atmosphere remained relatively stable, but a sudden expansion of the amount of methane happened worldwide almost simultaneously.
One particular theory points to a warm conditions over Siberia during 2007. Globally, the winter of 2006 and 2007 was warmer than average as can be seen in the discussion of the warmest years on record. Almost all of the United States saw above average temperatures for the winter of 2006/2007. The increased warmth in Siberia may have lead to increased bacterial emissions from wetland areas.
A delicate balance exists within our atmosphere that can cleanse the air of excess methane. The hydroxyl free radical will react with methane acting as a methane-breaker. In contrast, methane-makers include cattle, gas and coal industries, rice paddies, and wetlands. The increase in methane may also be a result of a reduction in the hydroxyl free radical.
The original research was published by the American Geophysical Union's Geophysical Review Letters by Matthew Rigby and Ronald Prinn of the Massachusetts Institute of Technology. In the press release on the findings, the lead authors discuss the role of methane in the atmosphere.
Methane levels have tripled since the Industrial Revolution. This is a potentially dangerous situation given that methane is about 25 times stronger as a greenhouse gas per metric ton of emissions than carbon dioxide. For nearly a decade, the amount of methane in the atmosphere remained relatively stable, but a sudden expansion of the amount of methane happened worldwide almost simultaneously.
One particular theory points to a warm conditions over Siberia during 2007. Globally, the winter of 2006 and 2007 was warmer than average as can be seen in the discussion of the warmest years on record. Almost all of the United States saw above average temperatures for the winter of 2006/2007. The increased warmth in Siberia may have lead to increased bacterial emissions from wetland areas.
A delicate balance exists within our atmosphere that can cleanse the air of excess methane. The hydroxyl free radical will react with methane acting as a methane-breaker. In contrast, methane-makers include cattle, gas and coal industries, rice paddies, and wetlands. The increase in methane may also be a result of a reduction in the hydroxyl free radical.
Scientists working in Antarctica have confirmed that levels of key greenhouse gases that contribute to global warming, such as carbon dioxide and methane, are higher today than at any time in the past 650,000 years.
Humans Responsible for Global Warming
Their research also shows that human activity is the cause of the dramatic increase, which refutes the arguments of skeptics who claim that today’s global warming trend is merely part of a naturally recurring temperature cycle.
"The levels of primary greenhouse gases such as methane, carbon dioxide and nitrous oxide are up dramatically since the Industrial Revolution, at a speed and magnitude that the Earth has not seen in hundreds of thousands of years," said Ed Brook, an ice core expert at Oregon State University. "There is now no question this is due to human influence."
Dramatic Increases in Greenhouse Gases
According to the research, published in the journal Science in November 2005, carbon dioxide levels today are 27 percent higher than the highest previous level in the last 650,000 years, and methane levels are 130 percent higher.
The Chemistry of Global Warming
By analyzing the ice chemistry of a two-mile-long ice core they drilled and extracted in 10-foot sections, scientists were able to determine temperatures at various times from the past. Air bubbles trapped within the ice contain air and greenhouse gases from hundreds of thousands of years ago, enabling scientists to assess air quality at many points throughout the millennia.
Looking More Deeply Into the Past
Earlier ice cores gave scientists data for the past 440,000 years, so this new research extends the scientific view by another 210,000 years. Still, it falls short of a period scientists are eager to study when climate conditions were similar to those in our own time.
Brook is co-chairman of a group of European and American scientists that plan to start drilling an ice core in the future that could produce ice and air bubbles that are between 1.2 million and 1.5 million years old, which would more than double the length of the scientific record on global warming.
Humans Responsible for Global Warming
Their research also shows that human activity is the cause of the dramatic increase, which refutes the arguments of skeptics who claim that today’s global warming trend is merely part of a naturally recurring temperature cycle.
"The levels of primary greenhouse gases such as methane, carbon dioxide and nitrous oxide are up dramatically since the Industrial Revolution, at a speed and magnitude that the Earth has not seen in hundreds of thousands of years," said Ed Brook, an ice core expert at Oregon State University. "There is now no question this is due to human influence."
Dramatic Increases in Greenhouse Gases
According to the research, published in the journal Science in November 2005, carbon dioxide levels today are 27 percent higher than the highest previous level in the last 650,000 years, and methane levels are 130 percent higher.
The Chemistry of Global Warming
By analyzing the ice chemistry of a two-mile-long ice core they drilled and extracted in 10-foot sections, scientists were able to determine temperatures at various times from the past. Air bubbles trapped within the ice contain air and greenhouse gases from hundreds of thousands of years ago, enabling scientists to assess air quality at many points throughout the millennia.
Looking More Deeply Into the Past
Earlier ice cores gave scientists data for the past 440,000 years, so this new research extends the scientific view by another 210,000 years. Still, it falls short of a period scientists are eager to study when climate conditions were similar to those in our own time.
Brook is co-chairman of a group of European and American scientists that plan to start drilling an ice core in the future that could produce ice and air bubbles that are between 1.2 million and 1.5 million years old, which would more than double the length of the scientific record on global warming.
The government of Brazil has unveiled a plan to slow deforestation of the Amazon rainforest by more than 70 percent between 2008 and 2018—a move that will also reduce greenhouse gas emissions significantly.
The plan, announced December 1, 2008 by President Luiz Inácio Lula da Silva and Environment Minister Carlos Minc, is the first time Brazil has set specific goals to reduce or slow down deforestation due to farming, ranching and illegal logging in the largest expanse of tropical rainforest on Earth.
"Just in terms of avoided deforestation in the Amazon, the plan foresees a reduction of 4.8 billion tons of carbon dioxide that won't be emitted up to 2018—which is more than the reduction efforts fixed by all the rich countries," Minc said.
Deforestation Increases Global Warming, Destroys Medicinal Plants
Amazon deforestation releases an estimated 400 million tons of carbon dioxide into the atmosphere every year—whether from farmers and ranchers burning trees to clear more land or from rotting wood that is part of the natural forest cycle—making Brazil the world’s sixth largest emitter of the greenhouse gas.
Tropical rainforests are sometimes called the “lungs of the Earth,” because they play such a vital role in absorbing carbon dioxide and releasing the oxygen that humans and animals must have to live.
The Amazon rainforest is also a rich source of medicinal plants and home to thousands of unique plant and animal species. According to some estimates, tropical rainforests may contain half of all known plant species. Scientists have used the specialized properties in native rainforest plants to create drugs that now treat cancer, heart disease, hypertension and many other diseases.
Deforestation destroys wildlife habitat and pushes native plants species to extinction.
Brazil Takes Multi-faceted Approach to Slowing Deforestation
According to Minc, the new plan will slow the rate of rainforest destruction by 72 percent as compared to the 7,330 square miles on average that were lost each year between 1996 and 2005.
Brazil succeeded in slowing deforestation in the Amazon by about 60 percent between 2005 and 2007, but deforestation accelerated again in 2008 as rising soy and beef prices encouraged Brazilian farmers to create more fields and pastures by slashing and burning rainforest land.
Brazil’s anti-deforestation plan would increase federal patrols in the rainforest, replant trees to replace those that have been lost, and finance sustainable development projects to offer viable work alternatives in areas where illegal logging is currently a major source of income.
"We need to offer to help them with one hand, but with the other we have to tell them there will be punishment if they don't pay attention to environmental preservation," Lula said. He didn’t explain the type of penalties he envisioned, nor did he say how much the rainforest preservation plan would cost.
The plan, announced December 1, 2008 by President Luiz Inácio Lula da Silva and Environment Minister Carlos Minc, is the first time Brazil has set specific goals to reduce or slow down deforestation due to farming, ranching and illegal logging in the largest expanse of tropical rainforest on Earth.
"Just in terms of avoided deforestation in the Amazon, the plan foresees a reduction of 4.8 billion tons of carbon dioxide that won't be emitted up to 2018—which is more than the reduction efforts fixed by all the rich countries," Minc said.
Deforestation Increases Global Warming, Destroys Medicinal Plants
Amazon deforestation releases an estimated 400 million tons of carbon dioxide into the atmosphere every year—whether from farmers and ranchers burning trees to clear more land or from rotting wood that is part of the natural forest cycle—making Brazil the world’s sixth largest emitter of the greenhouse gas.
Tropical rainforests are sometimes called the “lungs of the Earth,” because they play such a vital role in absorbing carbon dioxide and releasing the oxygen that humans and animals must have to live.
The Amazon rainforest is also a rich source of medicinal plants and home to thousands of unique plant and animal species. According to some estimates, tropical rainforests may contain half of all known plant species. Scientists have used the specialized properties in native rainforest plants to create drugs that now treat cancer, heart disease, hypertension and many other diseases.
Deforestation destroys wildlife habitat and pushes native plants species to extinction.
Brazil Takes Multi-faceted Approach to Slowing Deforestation
According to Minc, the new plan will slow the rate of rainforest destruction by 72 percent as compared to the 7,330 square miles on average that were lost each year between 1996 and 2005.
Brazil succeeded in slowing deforestation in the Amazon by about 60 percent between 2005 and 2007, but deforestation accelerated again in 2008 as rising soy and beef prices encouraged Brazilian farmers to create more fields and pastures by slashing and burning rainforest land.
Brazil’s anti-deforestation plan would increase federal patrols in the rainforest, replant trees to replace those that have been lost, and finance sustainable development projects to offer viable work alternatives in areas where illegal logging is currently a major source of income.
"We need to offer to help them with one hand, but with the other we have to tell them there will be punishment if they don't pay attention to environmental preservation," Lula said. He didn’t explain the type of penalties he envisioned, nor did he say how much the rainforest preservation plan would cost.
The global rate of human population growth peaked around 1963, but the number of people living on Earth—and sharing finite resources like water and food—has grown by more than two-thirds since then, topping out at over 6.6 billion today. Human population is expected to exceed nine billion by 2050. Environmentalists don’t dispute that many if not all of the environmental problems—from climate change to species loss to overzealous resource extraction—are either caused or exacerbated by population growth.
“Trends such as the loss of half of the planet’s forests, the depletion of most of its major fisheries, and the alteration of its atmosphere and climate are closely related to the fact that human population expanded from mere millions in prehistoric times to over six billion today,” says Robert Engelman of Population Action International.
Population Growth Causes Multiple Environmental Problems
According to Population Connection, population growth since 1950 is behind the clearing of 80 percent of rainforests, the loss of tens of thousands of plant and wildlife species, an increase in greenhouse gas emissions of some 400 percent and the development or commercialization of as much as half of the Earth’s surface land.
The group fears that in the coming decades half of the world’s population will be exposed to “water-stress” or “water-scarce” conditions, which are expected to “intensify difficulties in meeting…consumption levels, and wreak devastating effects on our delicately balanced ecosystems.”
Is Access to Contraception an Environmental Imperative?
In less developed countries, lack of access to birth control, as well as cultural traditions that encourage women to stay home and have babies, lead to rapid population growth. The result is ever increasing numbers of poor people across Africa, the Middle East, Southeast Asia, and elsewhere who suffer from malnourishment, lack of clean water, overcrowding, inadequate shelter, and AIDS and other diseases.
High-Consumption Lifestyles Exacerbate Problems of Population Growth
And while population numbers in most developed nations are leveling off or diminishing today, high levels of consumption make for a huge drain on resources. Americans, who represent only 4 percent of world population, consume 25 percent of all resources.
Industrialized countries also contribute far more to climate change, ozone depletion and overfishing than developing countries. And as more and more residents of developing countries get access to Western media, or immigrate to the United States, they want to emulate the consumption-heavy lifestyles they see on their televisions and read about on the Internet.
U.S. Policy Changes Could Help Control Population Growth Worldwide
Given the overlap of population growth and environmental problems, many would like to see a change in U.S. policy on global family planning. In 2001, President George W. Bush instituted what some call the “global gag rule,” whereby foreign organizations that provide or endorse abortions are denied U.S. funding support. Environmentalists consider that stance to be shortsighted, because support for family planning is the most effective way to check population growth and relieve pressure on the planet’s environment.
“Trends such as the loss of half of the planet’s forests, the depletion of most of its major fisheries, and the alteration of its atmosphere and climate are closely related to the fact that human population expanded from mere millions in prehistoric times to over six billion today,” says Robert Engelman of Population Action International.
Population Growth Causes Multiple Environmental Problems
According to Population Connection, population growth since 1950 is behind the clearing of 80 percent of rainforests, the loss of tens of thousands of plant and wildlife species, an increase in greenhouse gas emissions of some 400 percent and the development or commercialization of as much as half of the Earth’s surface land.
The group fears that in the coming decades half of the world’s population will be exposed to “water-stress” or “water-scarce” conditions, which are expected to “intensify difficulties in meeting…consumption levels, and wreak devastating effects on our delicately balanced ecosystems.”
Is Access to Contraception an Environmental Imperative?
In less developed countries, lack of access to birth control, as well as cultural traditions that encourage women to stay home and have babies, lead to rapid population growth. The result is ever increasing numbers of poor people across Africa, the Middle East, Southeast Asia, and elsewhere who suffer from malnourishment, lack of clean water, overcrowding, inadequate shelter, and AIDS and other diseases.
High-Consumption Lifestyles Exacerbate Problems of Population Growth
And while population numbers in most developed nations are leveling off or diminishing today, high levels of consumption make for a huge drain on resources. Americans, who represent only 4 percent of world population, consume 25 percent of all resources.
Industrialized countries also contribute far more to climate change, ozone depletion and overfishing than developing countries. And as more and more residents of developing countries get access to Western media, or immigrate to the United States, they want to emulate the consumption-heavy lifestyles they see on their televisions and read about on the Internet.
U.S. Policy Changes Could Help Control Population Growth Worldwide
Given the overlap of population growth and environmental problems, many would like to see a change in U.S. policy on global family planning. In 2001, President George W. Bush instituted what some call the “global gag rule,” whereby foreign organizations that provide or endorse abortions are denied U.S. funding support. Environmentalists consider that stance to be shortsighted, because support for family planning is the most effective way to check population growth and relieve pressure on the planet’s environment.
Are Levels of Greenhouse Gases Increasing?
Human activity is increasing the concentration of greenhouse gases in the atmosphere at a rate that has probably never been seen before in the planet's history. There is no serious scientific disagreement or debate on this point.
Greenhouse Gases at Record Levels
Prior to the start of the Industrial Revolution, the levels of carbon dioxide in the atmosphere were about 280 parts per million by volume (ppmv). Current levels are about 370 ppmv. The concentration of carbon dioxide and other key greenhouse gases in our atmosphere today is higher than at any time in the past 650,000 years, and probably higher than in the past 20 million years.
The Accumulation of Greenhouse Gases Continues
According to the Special Report on Emission Scenarios (SRES) from the Intergovernmental Panel on Climate Change, by the end of the 21st century we could expect to see carbon dioxide concentrations of anywhere from 490 ppmv to 1260 ppmv if we don't act now to lower greenhouse gas emissions that contribute to global warming. That's between 75 percent and 350 percent above pre-industrial concentrations
Human activity is increasing the concentration of greenhouse gases in the atmosphere at a rate that has probably never been seen before in the planet's history. There is no serious scientific disagreement or debate on this point.
Greenhouse Gases at Record Levels
Prior to the start of the Industrial Revolution, the levels of carbon dioxide in the atmosphere were about 280 parts per million by volume (ppmv). Current levels are about 370 ppmv. The concentration of carbon dioxide and other key greenhouse gases in our atmosphere today is higher than at any time in the past 650,000 years, and probably higher than in the past 20 million years.
The Accumulation of Greenhouse Gases Continues
According to the Special Report on Emission Scenarios (SRES) from the Intergovernmental Panel on Climate Change, by the end of the 21st century we could expect to see carbon dioxide concentrations of anywhere from 490 ppmv to 1260 ppmv if we don't act now to lower greenhouse gas emissions that contribute to global warming. That's between 75 percent and 350 percent above pre-industrial concentrations
Trees are important tools in the fight to stave off global warming, because they absorb and store the key greenhouse gas emitted by our cars and power plants, carbon dioxide (CO2), before it has a chance to reach the upper atmosphere where it can help trap heat around the Earth’s surface.
All Plants Absorb Carbon Dioxide, but Trees are Best
While all living plant matter absorbs CO2 as part of photosynthesis, trees process significantly more than smaller plants due to their large size and extensive root structures. In essence, trees, as kings of the plant world, have much more “woody biomass” to store CO2 than smaller plants, and as a result are considered nature’s most efficient “carbon sinks.”
According to the U.S. Department of Energy (DOE), tree species that grow quickly and live long are ideal carbon sinks. Unfortunately, these two attributes are usually mutually exclusive. Given the choice, foresters interested in maximizing the absorption and storage of CO2 (known as “carbon sequestration”) usually favor younger trees that grow more quickly than their older cohorts. However, slower growing trees can store much more carbon over their significantly longer lives.
Plant the Right Tree for the Right Location
Scientists are busy studying the carbon sequestration potential of different types of trees in various parts of the U.S., including Eucalyptus in Hawaii, loblolly pine in the Southeast, bottomland hardwoods in Mississippi, and poplars in the Great Lakes.
“There are literally dozens of tree species that could be planted depending upon location, climate and soils,” says Stan Wullschleger, a researcher at Tennessee’s Oak Ridge National Laboratory who specializes in the physiological response of plants to global climate change.
Choose Low-Maintenance Trees to Maximize Carbon Absorption
Dave Nowak, a researcher at the U.S. Forest Service’s Northern Research Station in Syracuse, New York has studied the use of trees for carbon sequestration in urban settings across the United States. A 2002 study he co-authored lists the Common Horse-chestnut, Black Walnut, American Sweetgum, Ponderosa Pine, Red Pine, White Pine, London Plane, Hispaniolan Pine, Douglas Fir, Scarlet Oak, Red Oak, Virginia Live Oak and Bald Cypress as examples of trees especially good at absorbing and storing CO2. Nowak advises urban land managers to avoid trees that require a lot of maintenance, as the burning of fossil fuels to power equipment like trucks and chainsaws will only erase the carbon absorption gains otherwise made.
Plant Any Tree Appropriate for Region and Climate to Offset Global Warming
Ultimately, trees of any shape, size or genetic origin help absorb CO2. Most scientists agree that the least expensive and perhaps easiest way for individuals to help offset the CO2 that they generate in their everyday lives is to plant a tree…any tree, as long as it is appropriate for the given region and climate.
Those who wish to help larger tree planting efforts can donate money or time to the National Arbor Day Foundation or American Forests in the U.S., or to the Tree Canada Foundation in Canada.
All Plants Absorb Carbon Dioxide, but Trees are Best
While all living plant matter absorbs CO2 as part of photosynthesis, trees process significantly more than smaller plants due to their large size and extensive root structures. In essence, trees, as kings of the plant world, have much more “woody biomass” to store CO2 than smaller plants, and as a result are considered nature’s most efficient “carbon sinks.”
According to the U.S. Department of Energy (DOE), tree species that grow quickly and live long are ideal carbon sinks. Unfortunately, these two attributes are usually mutually exclusive. Given the choice, foresters interested in maximizing the absorption and storage of CO2 (known as “carbon sequestration”) usually favor younger trees that grow more quickly than their older cohorts. However, slower growing trees can store much more carbon over their significantly longer lives.
Plant the Right Tree for the Right Location
Scientists are busy studying the carbon sequestration potential of different types of trees in various parts of the U.S., including Eucalyptus in Hawaii, loblolly pine in the Southeast, bottomland hardwoods in Mississippi, and poplars in the Great Lakes.
“There are literally dozens of tree species that could be planted depending upon location, climate and soils,” says Stan Wullschleger, a researcher at Tennessee’s Oak Ridge National Laboratory who specializes in the physiological response of plants to global climate change.
Choose Low-Maintenance Trees to Maximize Carbon Absorption
Dave Nowak, a researcher at the U.S. Forest Service’s Northern Research Station in Syracuse, New York has studied the use of trees for carbon sequestration in urban settings across the United States. A 2002 study he co-authored lists the Common Horse-chestnut, Black Walnut, American Sweetgum, Ponderosa Pine, Red Pine, White Pine, London Plane, Hispaniolan Pine, Douglas Fir, Scarlet Oak, Red Oak, Virginia Live Oak and Bald Cypress as examples of trees especially good at absorbing and storing CO2. Nowak advises urban land managers to avoid trees that require a lot of maintenance, as the burning of fossil fuels to power equipment like trucks and chainsaws will only erase the carbon absorption gains otherwise made.
Plant Any Tree Appropriate for Region and Climate to Offset Global Warming
Ultimately, trees of any shape, size or genetic origin help absorb CO2. Most scientists agree that the least expensive and perhaps easiest way for individuals to help offset the CO2 that they generate in their everyday lives is to plant a tree…any tree, as long as it is appropriate for the given region and climate.
Those who wish to help larger tree planting efforts can donate money or time to the National Arbor Day Foundation or American Forests in the U.S., or to the Tree Canada Foundation in Canada.
2006 was the warmest year on record in the United States and the sixth warmest worldwide, according to the National Climatic Data Center (NCDC) and the World Meteorological Organization (WMO) respectively, continuing a nine-year warming trend that scientists believe is unprecedented and may signal an acceleration of global warming.
What Caused the Exceptionally Warm Weather in 2006?
According to climate experts, the warmer-than-usual temperatures in 2006 were due to a combination of three factors:
· unusual regional weather patterns in several places that caused spring-like conditions through December and into early January;
· a cyclical El Niño effect in the Pacific Ocean; and
· the increase of carbon dioxide and other greenhouse gases in the atmosphere, which are creating an amplified greenhouse effect and contributing to global warming.
"People should be concerned about what we are doing to the climate," said Jay Lawrimore, chief of the climate monitoring branch of the National Oceanic and Atmospheric Administration (NOAA), in an interview with The Washington Post. "Burning of fossil fuels is causing an increase in greenhouse gases, and there's a broad scientific consensus that it is producing climate change."
Here are some other climate highlights for 2006:
· In the United States, average temperatures nationwide in 2006 were 2.2 degrees Fahrenheit higher than the mean temperatures nationwide for the 20th century.
· The global mean surface temperature in 2006 was 0.42 degrees Celsius above the 1961-1990 annual average of 14°C (or 57.2 degrees Fahrenheit), according to the WMO.
· 2006 was also the hottest year on record in the United Kingdom.
· December 2006 was the fourth-warmest December on record in the United States.
· Average temperatures for all 48 contiguous U.S. states were above average, or well above average for the year, and seven months in 2006 were much warmer than average.
· New Jersey recorded the hottest temperatures ever seen in that state.
· Because of the warmer U.S. temperatures from October through December, energy use for residential heating was 13.5 percent below average for those three months.
The Global Warming Debate is Over
There is no longer any serious scientific debate about whether global warming is occurring or whether greenhouse gases caused either directly or indirectly by human activities are contributing significantly to the warming trend. Where scientists still disagree is on the rate at which the global temperature is rising and how much time we have left to intervene before the planet reaches a tipping point past which there is no way to avoid or mitigate the potential devastating effects.
A single warm year is not something scientists would be concerned about, but the past nine years have all been among the hottest 25 years on record in the United States, and many have been among the warmest years globally. What has scientists worried is the trend of increasingly warm years, and a build up of greenhouse gases that is higher than at any time in the past 650,000 years (which is as far back as science has been able to take readings from ice core samples).
"No one should be surprised that 2006 is the hottest year on record for the U.S.," said Brenda Ekwurzel, a climate scientist with the Union of Concerned Scientists, in an interview with The Washington Post. "When you look at temperatures across the globe, every single year since 1993 has been in the top 20 warmest years on record."
"Realistically, we have to start fighting global warming in the next 10 years if we want to secure a safe environment for our children and grandchildren," she said.
What Caused the Exceptionally Warm Weather in 2006?
According to climate experts, the warmer-than-usual temperatures in 2006 were due to a combination of three factors:
· unusual regional weather patterns in several places that caused spring-like conditions through December and into early January;
· a cyclical El Niño effect in the Pacific Ocean; and
· the increase of carbon dioxide and other greenhouse gases in the atmosphere, which are creating an amplified greenhouse effect and contributing to global warming.
"People should be concerned about what we are doing to the climate," said Jay Lawrimore, chief of the climate monitoring branch of the National Oceanic and Atmospheric Administration (NOAA), in an interview with The Washington Post. "Burning of fossil fuels is causing an increase in greenhouse gases, and there's a broad scientific consensus that it is producing climate change."
Here are some other climate highlights for 2006:
· In the United States, average temperatures nationwide in 2006 were 2.2 degrees Fahrenheit higher than the mean temperatures nationwide for the 20th century.
· The global mean surface temperature in 2006 was 0.42 degrees Celsius above the 1961-1990 annual average of 14°C (or 57.2 degrees Fahrenheit), according to the WMO.
· 2006 was also the hottest year on record in the United Kingdom.
· December 2006 was the fourth-warmest December on record in the United States.
· Average temperatures for all 48 contiguous U.S. states were above average, or well above average for the year, and seven months in 2006 were much warmer than average.
· New Jersey recorded the hottest temperatures ever seen in that state.
· Because of the warmer U.S. temperatures from October through December, energy use for residential heating was 13.5 percent below average for those three months.
The Global Warming Debate is Over
There is no longer any serious scientific debate about whether global warming is occurring or whether greenhouse gases caused either directly or indirectly by human activities are contributing significantly to the warming trend. Where scientists still disagree is on the rate at which the global temperature is rising and how much time we have left to intervene before the planet reaches a tipping point past which there is no way to avoid or mitigate the potential devastating effects.
A single warm year is not something scientists would be concerned about, but the past nine years have all been among the hottest 25 years on record in the United States, and many have been among the warmest years globally. What has scientists worried is the trend of increasingly warm years, and a build up of greenhouse gases that is higher than at any time in the past 650,000 years (which is as far back as science has been able to take readings from ice core samples).
"No one should be surprised that 2006 is the hottest year on record for the U.S.," said Brenda Ekwurzel, a climate scientist with the Union of Concerned Scientists, in an interview with The Washington Post. "When you look at temperatures across the globe, every single year since 1993 has been in the top 20 warmest years on record."
"Realistically, we have to start fighting global warming in the next 10 years if we want to secure a safe environment for our children and grandchildren," she said.
What Causes the Greenhouse Effect?
Life on earth depends on energy from the sun. About 30 percent of the sunlight that beams toward Earth is deflected by the outer atmosphere and scattered back into space. The rest reaches the planet’s surface and is reflected upward again as a type of slow-moving energy called infrared radiation.
As it rises, infrared radiation is absorbed by “greenhouse gases” such as water vapor, carbon dioxide, ozone and methane, which slows its escape from the atmosphere.
Although greenhouse gases make up only about 1 percent of the Earth’s atmosphere, they regulate our climate by trapping heat and holding it in a kind of warm-air blanket that surrounds the planet.
This phenomenon is what scientists call the "greenhouse effect." Without it, scientists estimate that the average temperature on Earth would be colder by approximately 30 degrees Celsius (54 degrees Fahrenheit), far too cold to sustain our current ecosystem.
How Do Humans Contribute to the Greenhouse Effect?
While the greenhouse effect is an essential environmental prerequisite for life on Earth, there really can be too much of a good thing.
The problems begin when human activities distort and accelerate the natural process by creating more greenhouse gases in the atmosphere than are necessary to warm the planet to an ideal temperature.
· Burning natural gas, coal and oil —including gasoline for automobile engines—raises the level of carbon dioxide in the atmosphere.
· Some farming practices and land-use changes increase the levels of methane and nitrous oxide.
· Many factories produce long-lasting industrial gases that do not occur naturally, yet contribute significantly to the enhanced greenhouse effect and “global warming” that is currently under way.
· Deforestation also contributes to global warming. Trees use carbon dioxide and give off oxygen in its place, which helps to create the optimal balance of gases in the atmosphere. As more forests are logged for timber or cut down to make way for farming, however, there are fewer trees to perform this critical function.
· Population growth is another factor in global warming, because as more people use fossil fuels for heat, transportation and manufacturing the level of greenhouse gases continues to increase. As more farming occurs to feed millions of new people, more greenhouse gases enter the atmosphere.
Ultimately, more greenhouse gases means more infrared radiation trapped and held, which gradually increases the temperature of the Earth’s surface and the air in the lower atmosphere.
The Average Global Temperature is Increasing Quickly
Today, the increase in the Earth’s temperature is increasing with unprecedented speed. To understand just how quickly global warming is accelerating, consider this:
During the entire 20th century, the average global temperature increased by about 0.6 degrees Celsius (slightly more than 1 degree Fahrenheit).
Using computer climate models, scientists estimate that by the year 2100 the average global temperature will increase by 1.4 degrees to 5.8 degrees Celsius (approximately 2.5 degrees to 10.5 degrees Fahrenheit).
Not All Scientists Agree
While the majority of mainstream scientists agree that global warming is a serious problem that is growing steadily worse, there are some who disagree. John Christy, a professor and director of the Earth System Science Center at the University of Alabama in Huntsville is a respected climatologist who argues that global warming isn’t worth worrying about.
Christy reached that opinion after analyzing millions of measurements from weather satellites in an effort to find a global temperature trend. He found no sign of global warming in the satellite data, and now believes that predictions of global warming by as much as 10 degrees Fahrenheit by the end of the 21st century are incorrect.
Life on earth depends on energy from the sun. About 30 percent of the sunlight that beams toward Earth is deflected by the outer atmosphere and scattered back into space. The rest reaches the planet’s surface and is reflected upward again as a type of slow-moving energy called infrared radiation.
As it rises, infrared radiation is absorbed by “greenhouse gases” such as water vapor, carbon dioxide, ozone and methane, which slows its escape from the atmosphere.
Although greenhouse gases make up only about 1 percent of the Earth’s atmosphere, they regulate our climate by trapping heat and holding it in a kind of warm-air blanket that surrounds the planet.
This phenomenon is what scientists call the "greenhouse effect." Without it, scientists estimate that the average temperature on Earth would be colder by approximately 30 degrees Celsius (54 degrees Fahrenheit), far too cold to sustain our current ecosystem.
How Do Humans Contribute to the Greenhouse Effect?
While the greenhouse effect is an essential environmental prerequisite for life on Earth, there really can be too much of a good thing.
The problems begin when human activities distort and accelerate the natural process by creating more greenhouse gases in the atmosphere than are necessary to warm the planet to an ideal temperature.
· Burning natural gas, coal and oil —including gasoline for automobile engines—raises the level of carbon dioxide in the atmosphere.
· Some farming practices and land-use changes increase the levels of methane and nitrous oxide.
· Many factories produce long-lasting industrial gases that do not occur naturally, yet contribute significantly to the enhanced greenhouse effect and “global warming” that is currently under way.
· Deforestation also contributes to global warming. Trees use carbon dioxide and give off oxygen in its place, which helps to create the optimal balance of gases in the atmosphere. As more forests are logged for timber or cut down to make way for farming, however, there are fewer trees to perform this critical function.
· Population growth is another factor in global warming, because as more people use fossil fuels for heat, transportation and manufacturing the level of greenhouse gases continues to increase. As more farming occurs to feed millions of new people, more greenhouse gases enter the atmosphere.
Ultimately, more greenhouse gases means more infrared radiation trapped and held, which gradually increases the temperature of the Earth’s surface and the air in the lower atmosphere.
The Average Global Temperature is Increasing Quickly
Today, the increase in the Earth’s temperature is increasing with unprecedented speed. To understand just how quickly global warming is accelerating, consider this:
During the entire 20th century, the average global temperature increased by about 0.6 degrees Celsius (slightly more than 1 degree Fahrenheit).
Using computer climate models, scientists estimate that by the year 2100 the average global temperature will increase by 1.4 degrees to 5.8 degrees Celsius (approximately 2.5 degrees to 10.5 degrees Fahrenheit).
Not All Scientists Agree
While the majority of mainstream scientists agree that global warming is a serious problem that is growing steadily worse, there are some who disagree. John Christy, a professor and director of the Earth System Science Center at the University of Alabama in Huntsville is a respected climatologist who argues that global warming isn’t worth worrying about.
Christy reached that opinion after analyzing millions of measurements from weather satellites in an effort to find a global temperature trend. He found no sign of global warming in the satellite data, and now believes that predictions of global warming by as much as 10 degrees Fahrenheit by the end of the 21st century are incorrect.
What are Greenhouse Gases?
Many greenhouse gases occur naturally, such as water vapor, carbon dioxide, methane, nitrous oxide, and ozone. Others such as hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6) result exclusively from human industrial processes.
Human Activities and Greenhouse Gases
Human activities also add significantly to the level of naturally occurring greenhouse gases:
· Carbon dioxide is released into the atmosphere by the burning of solid waste, wood and wood products, and fossil fuels (oil, natural gas, and coal).
· Nitrous oxide emissions occur during various agricultural and industrial processes, and when solid waste or fossil fuels are burned.
· Methane is emitted when organic waste decomposes, whether in landfills or in connection with livestock farming. Methane emissions also occur during the production and transport of fossil fuels.
The Properties of Greenhouse Gases
Greenhouse gases vary in their ability to absorb and hold heat in the atmosphere, a phenomenon known as the "greenhouse effect." HFCs and PFCs are the most heat-absorbent, but there are also wide differences between naturally occurring gases. For example, nitrous oxide absorbs 270 times more heat per molecule than carbon dioxide, and methane absorbs 21 times more heat per molecule than carbon dioxide.
Many greenhouse gases occur naturally, such as water vapor, carbon dioxide, methane, nitrous oxide, and ozone. Others such as hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6) result exclusively from human industrial processes.
Human Activities and Greenhouse Gases
Human activities also add significantly to the level of naturally occurring greenhouse gases:
· Carbon dioxide is released into the atmosphere by the burning of solid waste, wood and wood products, and fossil fuels (oil, natural gas, and coal).
· Nitrous oxide emissions occur during various agricultural and industrial processes, and when solid waste or fossil fuels are burned.
· Methane is emitted when organic waste decomposes, whether in landfills or in connection with livestock farming. Methane emissions also occur during the production and transport of fossil fuels.
The Properties of Greenhouse Gases
Greenhouse gases vary in their ability to absorb and hold heat in the atmosphere, a phenomenon known as the "greenhouse effect." HFCs and PFCs are the most heat-absorbent, but there are also wide differences between naturally occurring gases. For example, nitrous oxide absorbs 270 times more heat per molecule than carbon dioxide, and methane absorbs 21 times more heat per molecule than carbon dioxide.
solution----------------->Kyoto Protocol...
At the Rio Earth Summit, Parties to the Framework Convention on Climate Change (FCCC) agreed to stabilise emissions of greenhouse gases at 1990 levels by the year 2000, in an attempt to mitigate the threat of global warming. Following this an historic agreement to actually cut emissions was agreed in December 1997 in Kyoto, Japan, at the third Conference of Parties to the FCCC. Industrial nations agreed to reduce their collective emissions of greenhouse gases by 5.2% from 1990 levels by the period 2008 to 2012.
Crucially, the Kyoto Protocol committed developed countries to make legally binding reductions in their greenhouse gas emissions. The six gases that were considered are carbon dioxide, methane, nitrous oxide, and replacements to the HCFCs, which are to be gradually phased over the next 30 years. These include the hydrofluorocarbons or HFCs, the perfluorocarbons or PFCs and sulphur hexafluoride.
The Kyoto Protocol was endorsed by 160 countries. It will become legally binding provided at least 55 countries sign up to it, including developed nations responsible for at least 55% of greenhouse gas emissions from the industrialised world. The global cut in emissions of 5.2% is to be achieved by differential reductions for individual countries. The European Union, Switzerland and the majority of Central and Eastern European nations will deliver reductions of 8%; the US will cut emissions by 7%; and Japan, Hungary, Canada and Poland by 6%. New Zealand, Russia and the Ukraine are required to stabilise their emissions, whilst Australia, Iceland and Norway are permitted to increase slightly, although at a reduced rate to current trends. Within the European Union, further differential reduction rates apply. The UK has committed itself to a 12.5% reduction, although it has also set its own domestic target of a 20% reduction in carbon dioxide by 2010.
Crucially, the Kyoto Protocol committed developed countries to make legally binding reductions in their greenhouse gas emissions. The six gases that were considered are carbon dioxide, methane, nitrous oxide, and replacements to the HCFCs, which are to be gradually phased over the next 30 years. These include the hydrofluorocarbons or HFCs, the perfluorocarbons or PFCs and sulphur hexafluoride.
The Kyoto Protocol was endorsed by 160 countries. It will become legally binding provided at least 55 countries sign up to it, including developed nations responsible for at least 55% of greenhouse gas emissions from the industrialised world. The global cut in emissions of 5.2% is to be achieved by differential reductions for individual countries. The European Union, Switzerland and the majority of Central and Eastern European nations will deliver reductions of 8%; the US will cut emissions by 7%; and Japan, Hungary, Canada and Poland by 6%. New Zealand, Russia and the Ukraine are required to stabilise their emissions, whilst Australia, Iceland and Norway are permitted to increase slightly, although at a reduced rate to current trends. Within the European Union, further differential reduction rates apply. The UK has committed itself to a 12.5% reduction, although it has also set its own domestic target of a 20% reduction in carbon dioxide by 2010.
IsLaNdS aNd CoAsTs......
Global warming will cause sea level to rise as result of melting ice and a thermal expansion of the oceans. Higher sea levels will threaten small low-lying islands in the Pacific and Indian Oceans. Island nations such as the Maldives and the Pacific atolls lie only a few metres above sea level. Increased storm damage will pose the most immediate risk, but ultimately such islands may become completely submerged.
Low-lying coastal regions of the world are also under threat from sea level rise, storm damage and tidal surges. Some of the most vulnerable land is found in unprotected, densely populated and economically productive coastal regions of countries with poor financial and technological resources for responding to sea level rise, such as Bangladesh. The projected future rise in sea level may be only tens of centimetres, but this would be enough to put millions of people and millions of square kilometres of land at risk. The costs of protecting this land from the sea and preventing constant erosion and the salination of fresh groundwater supplies would be enormous. Additional investments would also be needed to adapt sewage systems and other coastal infrastructure. Rapid sea-level rise will also damage the coastal ecology, threatening important fisheries.
Effects on the sea level......
The global sea level has already risen by around between 10 to 25 centimetres during the last 100 years, at the rate of 1 to 2 millimetres per year. Measuring past and current changes in sea level, however, is extremely difficult. There are many potential sources of error and systematic bias, such as the uneven geographical distribution of measuring sites and the effect of the land itself as it rises and subsides.
It is likely that most of this rise in sea level has been due to the increase in global temperature over the last 100 years. Global warming should, on average, cause the oceans to warm and expand thus increasing sea level. Climate models indicate that about 25% of the rise in sea level this century has been due to the thermal expansion of seawater. A second major cause of rising sea level is the melting of land-based ice caps. Presently, it is uncertain to what extent the melting of the Greenland and Antarctic ice caps has contributed to global sea level rise during the 20th century.
Forecasts of a rising sea level are based on climate model results, which indicate that the Earth's average surface temperature may increase by between 1.4 and 5.8oC during the 21st century. Global warming is expected to cause a further rise of between 9 and 88 centimetres by the year 2100, with a best estimate of 50 centimetres, if emissions of greenhouse gases remain uncontrolled. This expected rate of change (an average of 5 cm per decade) is significantly faster than that experienced over the last 100 years.
Forecasting sea level rise, however, involves many uncertainties. While most scientists believe that man-made greenhouse gas emissions are changing the climate, they are less sure about the details, and particularly the speed, of this change. Global warming is the main potential impact of greenhouse gas emissions, but other aspects of the climate besides temperature may also change. For example, some studies suggest that changes in precipitation will increase snow accumulation in Antarctica, which may help to moderate the net sea level rise. Another complication is that the sea level would not rise by the same amount all over the globe due to the effects of the Earth’s rotation, local coastline variations, changes in major ocean currents, regional land subsidence and emergence, and differences in tidal patterns and sea water density.
Nevertheless, some areas of Antarctica have warmed by 2.5oC during the past 50 years, a rate of warming 5 times faster than for the Earth as a whole. Whilst scientists believe this to reflect mostly regional changes in climate, the recent summertime disintegration of the Larsen Ice Shelf has renewed speculation that climatic changes in the polar regions have the potential to cause severe impacts via a rise in global sea level over the next 100 to 200 years.
Effects on human health.............
Global warming is likely to have wide-ranging and mostly adverse impacts on human health, with significant loss of life. The most vulnerable populations to the impacts of climate change will be those already under pressure from social, economic and existing climate stresses. These will include those in developing countries, in the lower income groups, residents of coastal lowlands and islands, populations in semi-arid grasslands, and the urban poor. Increased exposure to natural hazards and extreme weather, such as coastal or river flooding, drought, landslides, storms and hurricanes, will prove detrimental to those most at risk.
Direct health impacts from climate change are likely to arise from the increased occurrence and magnitude of extreme weather events. Such direct effects may include heat-related stress and death, and deaths from flooding and landslides. An increased frequency or severity of heat waves would cause an increase in mortality, heart attacks and breathing illnesses. In very large cities, this would represent several thousand extra deaths annually. However, the number of cold-related deaths may decrease, partially offsetting deaths due to heat waves.
A significant indirect effect arising from global warming will be an increase in the range of vector-borne diseases such as malaria. Malarial mosquitoes may spread to higher latitudes and higher altitudes, taking advantage of the warmer temperatures. Approximately 45% of the world's population presently live in the climate zone where mosquitoes transmit malaria. Climate models predict that this will increase to about 60% by the second half of the 21st century, with maybe 80 million extra cases of malaria occurring each year. Increases in food- and water-related infections could also occur, particularly in tropical and subtropical regions. Warmer temperatures, reduced water supplies, and proliferating micro-organisms would lead to a higher incidence of diarrhoea, cholera, salmonellosis, and other such infections. Local reductions in food production could increase malnutrition and hunger, with long-term health consequences, particularly for children.
Warming of local and regional climates may enhance episodes of air pollution, particularly in urban centres, increasing the incidence of respiratory diseases. Asthma and other allergic disorders could result from climate-induced changes in the formation and persistence of pollens, spores, and certain air pollutants.
Poorer communities will be more vulnerable than richer ones. However, richer countries will also be increasingly vulnerable as their populations age. Health risks can be addressed through various adaptation strategies. Adaptive options to minimise health impacts may include improved and extended medical care services, better housing and air conditioning, water purification and public education. The lack of resources will be a constraint in many regions, but negative health effects can be minimised through a transfer of technological, educational and medical expertise from the more developed nations to the less developed nations.
Warming of local and regional climates may enhance episodes of air pollution, particularly in urban centres, increasing the incidence of respiratory diseases. Asthma and other allergic disorders could result from climate-induced changes in the formation and persistence of pollens, spores, and certain air pollutants.
Poorer communities will be more vulnerable than richer ones. However, richer countries will also be increasingly vulnerable as their populations age. Health risks can be addressed through various adaptation strategies. Adaptive options to minimise health impacts may include improved and extended medical care services, better housing and air conditioning, water purification and public education. The lack of resources will be a constraint in many regions, but negative health effects can be minimised through a transfer of technological, educational and medical expertise from the more developed nations to the less developed nations.
ImPaCtS oF gLoBaL wArMiNg...
If the climate changes in response to an enhanced greenhouse effect as current computer models have projected, global average surface temperature could be anywhere from 1.4 to 5.8°C (with a best estimate of 3°C) higher by the end of the 21st century. To put this temperature change into context, the increase in global average surface temperature which brought the Earth out of the last major ice age 14,000 years ago was of the order of 4 to 5°C. This climate change took thousands of years. Man-made global warming, in contrast, may occur at rate that is unprecedented on Earth.
Such a rapid change in climate will probably be too great to allow many ecosystems to suitably adapt, and the rate of species extinction will most likely increase. In addition to impacts on wildlife and species biodiversity, human agriculture, forestry, drylands, water resources and health will all be affected. Such impacts will be related to changes in precipitation (rainfall and snowfall), sea level, and the frequency and intensity of extreme weather events, resulting from global warming. It is expected that the societies currently experiencing existing social, economic and climatic stresses will be both worst affected and least able to adapt. These will include many in the developing world, low-lying islands and coastal regions, and the urban poor.
Such a rapid change in climate will probably be too great to allow many ecosystems to suitably adapt, and the rate of species extinction will most likely increase. In addition to impacts on wildlife and species biodiversity, human agriculture, forestry, drylands, water resources and health will all be affected. Such impacts will be related to changes in precipitation (rainfall and snowfall), sea level, and the frequency and intensity of extreme weather events, resulting from global warming. It is expected that the societies currently experiencing existing social, economic and climatic stresses will be both worst affected and least able to adapt. These will include many in the developing world, low-lying islands and coastal regions, and the urban poor.
Monday, April 6, 2009
Deforestation
Forests cover around a quarter to a third of the total land surface of the Earth. The reduction in area of this valuable environmental, social and economic resource through deforestation has the potential to cause problems on a global scale. Climate models have demonstrated a clear link between deforestation and climate change.
Deforestation is the process of changing land use from forestry to a non-forest use. Western Europe has already lost over 99% of its primary forest. Today, deforestation programmes focus on the major rainforests of the tropics. In the 1980s global deforestation was estimated at 17 to 20 million hectares per year, equivalent to the size of Britain. Current tropical tree planting programmes are not keeping pace with this rate of deforestation. Countries in these areas are often under-developed and striving for improved economies. Deforestation for wood and agricultural land can provide numerous economic benefits, but can have damaging environmental impacts on forest ecosystems and can affect local and regional climate.
Forests absorb a lot of sunlight for photosynthesis, and only about 12 to 15% is reflected. The large amounts of energy absorbed by forests acts to stimulate convection currents in air which enhance the production of rainfall. Tropical rainforests in particular are very wet and humid places. Deforested areas, by contrast, reflect about 20% of incoming sunlight. Deforested areas consequently, can become drier as a result of the loss of vegetation, increasing the risk of desertification. As the area of deforestation increases, so the impact on climate grows.
Trees also absorb carbon dioxide from the atmosphere for photosynthesis, and therefore help to regulate the natural greenhouse effect. Deforestation takes away a potential sink for the carbon dioxide mankind is pumping into the atmosphere. In addition, if forests are removed by burning, a lot of extra carbon dioxide locked up in tree wood is returned to the atmosphere.
Forests cover around a quarter to a third of the total land surface of the Earth. The reduction in area of this valuable environmental, social and economic resource through deforestation has the potential to cause problems on a global scale. Climate models have demonstrated a clear link between deforestation and climate change.
Deforestation is the process of changing land use from forestry to a non-forest use. Western Europe has already lost over 99% of its primary forest. Today, deforestation programmes focus on the major rainforests of the tropics. In the 1980s global deforestation was estimated at 17 to 20 million hectares per year, equivalent to the size of Britain. Current tropical tree planting programmes are not keeping pace with this rate of deforestation. Countries in these areas are often under-developed and striving for improved economies. Deforestation for wood and agricultural land can provide numerous economic benefits, but can have damaging environmental impacts on forest ecosystems and can affect local and regional climate.
Forests absorb a lot of sunlight for photosynthesis, and only about 12 to 15% is reflected. The large amounts of energy absorbed by forests acts to stimulate convection currents in air which enhance the production of rainfall. Tropical rainforests in particular are very wet and humid places. Deforested areas, by contrast, reflect about 20% of incoming sunlight. Deforested areas consequently, can become drier as a result of the loss of vegetation, increasing the risk of desertification. As the area of deforestation increases, so the impact on climate grows.
Trees also absorb carbon dioxide from the atmosphere for photosynthesis, and therefore help to regulate the natural greenhouse effect. Deforestation takes away a potential sink for the carbon dioxide mankind is pumping into the atmosphere. In addition, if forests are removed by burning, a lot of extra carbon dioxide locked up in tree wood is returned to the atmosphere.
DEFORESTATION
Deforestation is the permanent destruction of indigenous forests and woodlands. The term does not include the removal of industrial forests such as plantations of gums or pines. Deforestation has resulted in the reduction of indigenous forests to four-fifths of their pre-agricultural area. Indigenous forests now cover 21% of the earth's land surface.
WHAT ARE FORESTS AND WOODLANDS?
In a forest the crowns of individual trees touch to form a single canopy. In a woodland, trees grow far apart, so that the canopy is open.
GOING, GOING GONE!
Of great concern is the rate at which deforestation is occurring. Currently, 12 million hectares of forests are cleared annually - an area 1,3 times the size of KwaZulu/Natal! Almost all of this deforestation occurs in the moist forests and open woodlands of the tropics. At this rate all moist tropical forest could be lost by the year 2050, except for isolated areas in Amazonia, the Zaire basin, as well as a few protected areas within reserves and parks. Some countries such as Ivory Coast, Nigeria, Costa Rica, and Sri Lanka are likely to lose all their tropical forests by the year 2010 if no conservation steps are taken.
HOW DOES IT HAPPEN?
Deforestation is brought about by the following:
* conversion of forests and woodlands to agricultural land to feed growing numbers of people;
* development of cash crops and cattle ranching, both of which earn money for tropical countries;
* commercial logging (which supplies the world market with woods such as meranti, teak, mahogany and ebony) destroys trees as well as opening up forests for agriculture;
* felling of trees for firewood and building material; the heavy lopping of foliage for fodder; and heavy browsing of saplings by domestic animals like goats.
To compound the problem, the poor soils of the humid tropics do not support agriculture for long. Thus people are often forced to move on and clear more forests in order to maintain production.
CONSEQUENCES OF DEFORESTATION
* Alteration of local and global climates through disruption of:
a) The carbon cycle. Forests act as a major carbon store because carbon dioxide (CO2) is taken up from the atmosphere and used to produce the carbohydrates, fats, and proteins that make up the tree. When forests are cleared, and the trees are either burnt or rot, this carbon is released as CO2. This leads to an increase in the atmospheric CO2 concentration. CO2 is the major contributor to the greenhouse effect. It is estimated that deforestation contributes one-third of all CO2 releases caused by people.
b) The water cycle. Trees draw ground water up through their roots and release it into the atmosphere (transpiration). In Amazonia over half of all the water circulating through the region's ecosystem remains within the plants. With removal of part of the forest, the region cannot hold as much water. The effect of this could be a drier climate.
* Soil erosion With the loss of a protective cover of vegetation more soil is lost.
* Silting of water courses, lakes and dams This occurs as a result of soil erosion.
* Extinction of species which depend on the forest for survival. Forests contain more than half of all species on our planet - as the habitat of these species is destroyed, so the number of species declines (see Enviro Facts "Biodiversity").
* Desertification The causes of desertification are complex, but deforestation is one of the contributing factors (see Enviro Facts "Desertification")
Deforestation is the permanent destruction of indigenous forests and woodlands. The term does not include the removal of industrial forests such as plantations of gums or pines. Deforestation has resulted in the reduction of indigenous forests to four-fifths of their pre-agricultural area. Indigenous forests now cover 21% of the earth's land surface.
WHAT ARE FORESTS AND WOODLANDS?
In a forest the crowns of individual trees touch to form a single canopy. In a woodland, trees grow far apart, so that the canopy is open.
GOING, GOING GONE!
Of great concern is the rate at which deforestation is occurring. Currently, 12 million hectares of forests are cleared annually - an area 1,3 times the size of KwaZulu/Natal! Almost all of this deforestation occurs in the moist forests and open woodlands of the tropics. At this rate all moist tropical forest could be lost by the year 2050, except for isolated areas in Amazonia, the Zaire basin, as well as a few protected areas within reserves and parks. Some countries such as Ivory Coast, Nigeria, Costa Rica, and Sri Lanka are likely to lose all their tropical forests by the year 2010 if no conservation steps are taken.
HOW DOES IT HAPPEN?
Deforestation is brought about by the following:
* conversion of forests and woodlands to agricultural land to feed growing numbers of people;
* development of cash crops and cattle ranching, both of which earn money for tropical countries;
* commercial logging (which supplies the world market with woods such as meranti, teak, mahogany and ebony) destroys trees as well as opening up forests for agriculture;
* felling of trees for firewood and building material; the heavy lopping of foliage for fodder; and heavy browsing of saplings by domestic animals like goats.
To compound the problem, the poor soils of the humid tropics do not support agriculture for long. Thus people are often forced to move on and clear more forests in order to maintain production.
CONSEQUENCES OF DEFORESTATION
* Alteration of local and global climates through disruption of:
a) The carbon cycle. Forests act as a major carbon store because carbon dioxide (CO2) is taken up from the atmosphere and used to produce the carbohydrates, fats, and proteins that make up the tree. When forests are cleared, and the trees are either burnt or rot, this carbon is released as CO2. This leads to an increase in the atmospheric CO2 concentration. CO2 is the major contributor to the greenhouse effect. It is estimated that deforestation contributes one-third of all CO2 releases caused by people.
b) The water cycle. Trees draw ground water up through their roots and release it into the atmosphere (transpiration). In Amazonia over half of all the water circulating through the region's ecosystem remains within the plants. With removal of part of the forest, the region cannot hold as much water. The effect of this could be a drier climate.
* Soil erosion With the loss of a protective cover of vegetation more soil is lost.
* Silting of water courses, lakes and dams This occurs as a result of soil erosion.
* Extinction of species which depend on the forest for survival. Forests contain more than half of all species on our planet - as the habitat of these species is destroyed, so the number of species declines (see Enviro Facts "Biodiversity").
* Desertification The causes of desertification are complex, but deforestation is one of the contributing factors (see Enviro Facts "Desertification")
WHAT IS A GREENHOUSE EFFECTS?
The greenhouse effect is the rise in temperature that the Earth experiences because certain gases in the atmosphere (water vapor, carbon dioxide, nitrous oxide, and methane, for example) trap energy from the sun. Without these gases, heat would escape back into space and Earth’s average temperature would be about 60ºF colder. Because of how they warm our world, these gases are referred to as greenhouse gases.
Have you ever seen a greenhouse? Most greenhouses look like a small glass house. Greenhouses are used to grow plants, especially in the winter. Greenhouses work by trapping heat from the sun. The glass panels of the greenhouse let in light but keep heat from escaping. This causes the greenhouse to heat up, much like the inside of a car parked in sunlight, and keeps the plants warm enough to live in the winter.The Earth’s atmosphere is all around us. It is the air that we breathe. Greenhouse gases in the atmosphere behave much like the glass panes in a greenhouse. Sunlight enters the Earth's atmosphere, passing through the blanket of greenhouse gases. As it reaches the Earth's surface, land, water, and biosphere absorb the sunlight’s energy. Once absorbed, this energy is sent back into the atmosphere. Some of the energy passes back into space, but much of it remains trapped in the atmosphere by the greenhouse gases, causing our world to heat up.
The greenhouse effect is important. Without the greenhouse effect, the Earth would not be warm enough for humans to live. But if the greenhouse effect becomes stronger, it could make the Earth warmer than usual. Even a little extra warming may cause problems for humans, plants, and animals.
The greenhouse effect is the rise in temperature that the Earth experiences because certain gases in the atmosphere (water vapor, carbon dioxide, nitrous oxide, and methane, for example) trap energy from the sun. Without these gases, heat would escape back into space and Earth’s average temperature would be about 60ºF colder. Because of how they warm our world, these gases are referred to as greenhouse gases.
Have you ever seen a greenhouse? Most greenhouses look like a small glass house. Greenhouses are used to grow plants, especially in the winter. Greenhouses work by trapping heat from the sun. The glass panels of the greenhouse let in light but keep heat from escaping. This causes the greenhouse to heat up, much like the inside of a car parked in sunlight, and keeps the plants warm enough to live in the winter.The Earth’s atmosphere is all around us. It is the air that we breathe. Greenhouse gases in the atmosphere behave much like the glass panes in a greenhouse. Sunlight enters the Earth's atmosphere, passing through the blanket of greenhouse gases. As it reaches the Earth's surface, land, water, and biosphere absorb the sunlight’s energy. Once absorbed, this energy is sent back into the atmosphere. Some of the energy passes back into space, but much of it remains trapped in the atmosphere by the greenhouse gases, causing our world to heat up.
The greenhouse effect is important. Without the greenhouse effect, the Earth would not be warm enough for humans to live. But if the greenhouse effect becomes stronger, it could make the Earth warmer than usual. Even a little extra warming may cause problems for humans, plants, and animals.
GLOBAL WARMING – CAUSES
Global warming has a variety of causes. One of the largest factors contributing to global warming is the general problem of overpopulation and its many effects.
The greater number of people consume more items which take more energy to make, they drive more cars, and create larger amounts of garbage. These factors all increase the global warming problem.
Many different gases can increase the planet's temperature. The number of different products and human activities that contribute to global warming are so numerous that finding solutions to the problem is very difficult.
Using a refrigerator releases dangerous gases, turning on the lights requires energy from a power plant, and driving to work causes gas emissions from the car. Countless other normal activities lead to global warming.
Though having an atmosphere is important, the greenhouse effect may be making it excessively thick. The levels of gases covering the Earth have soared with industrialization, and developed countries now produce about 75% of greenhouse gases.
The most common gas is carbon dioxide, accounting for about 50% of all greenhouse gases. Other gases, including methane, CFCs, nitrogen oxides, and ozone, also contribute to forming the greenhouse layer.
Because these gases are produced by so many important and common processes, limiting their production to prevent global warming will be difficult. As population increases and Third World countries begin to use greater amounts of energy, the problem may expand rather than contract.
Global warming has a variety of causes. One of the largest factors contributing to global warming is the general problem of overpopulation and its many effects.
The greater number of people consume more items which take more energy to make, they drive more cars, and create larger amounts of garbage. These factors all increase the global warming problem.
Many different gases can increase the planet's temperature. The number of different products and human activities that contribute to global warming are so numerous that finding solutions to the problem is very difficult.
Using a refrigerator releases dangerous gases, turning on the lights requires energy from a power plant, and driving to work causes gas emissions from the car. Countless other normal activities lead to global warming.
Though having an atmosphere is important, the greenhouse effect may be making it excessively thick. The levels of gases covering the Earth have soared with industrialization, and developed countries now produce about 75% of greenhouse gases.
The most common gas is carbon dioxide, accounting for about 50% of all greenhouse gases. Other gases, including methane, CFCs, nitrogen oxides, and ozone, also contribute to forming the greenhouse layer.
Because these gases are produced by so many important and common processes, limiting their production to prevent global warming will be difficult. As population increases and Third World countries begin to use greater amounts of energy, the problem may expand rather than contract.
FOSSIL FUELS RESOURSES
Fossil fuels are a non-renewable resource. They are used in the production of energy, and have been consumed at increasing rates in recent history.
Fossil fuels include coal, natural gas, and oil. All three of these are available in a fixed supply, and are being rapidly depleted.
The first major use of fossil fuels began during the Industrial Revolution in the 18th century. However, it took until the beginning of the 20th century for coal to replace wood as the dominant source of fuel for the new industrial economy.
Coal took over because it became much easier and cheaper to mine, and it was a better source of energy than wood.
Within ten years, oil and natural gas replaced coal. These fossil fuels are cleaner than coal, and easier to transport. Also, oil can be used when liquid fuel is needed.
In the 1970s, the world and especially the US experienced serious fossil fuel shortages. When OPEC put an embargo against the United States, many people began to conserve energy and realize the effects of a lack of fossil fuels.
In 1984, the three major fossil fuels accounted for 82% of the world's commercial energy production. In the US, 91% of the energy supply came from burning those fossil fuels.
Throughout the history of industrialization, major changes have occurred. In the beginning, the industrializing countries used substances such as wood that were available locally to generate energy. Now, by contrast, the developed countries rely on fossil fuels that are transported to them.
Fossil fuels are a non-renewable resource. They are used in the production of energy, and have been consumed at increasing rates in recent history.
Fossil fuels include coal, natural gas, and oil. All three of these are available in a fixed supply, and are being rapidly depleted.
The first major use of fossil fuels began during the Industrial Revolution in the 18th century. However, it took until the beginning of the 20th century for coal to replace wood as the dominant source of fuel for the new industrial economy.
Coal took over because it became much easier and cheaper to mine, and it was a better source of energy than wood.
Within ten years, oil and natural gas replaced coal. These fossil fuels are cleaner than coal, and easier to transport. Also, oil can be used when liquid fuel is needed.
In the 1970s, the world and especially the US experienced serious fossil fuel shortages. When OPEC put an embargo against the United States, many people began to conserve energy and realize the effects of a lack of fossil fuels.
In 1984, the three major fossil fuels accounted for 82% of the world's commercial energy production. In the US, 91% of the energy supply came from burning those fossil fuels.
Throughout the history of industrialization, major changes have occurred. In the beginning, the industrializing countries used substances such as wood that were available locally to generate energy. Now, by contrast, the developed countries rely on fossil fuels that are transported to them.
CAUSES OF GLOBAL WARMING
Activity and Percent Contribution to Global Warming
Energy use and production 57%
Chlorofluorocarbons 17%
Agricultural practices 14%
Changes in land use 9%
Other industrial activities 3%
Source: C&EN, March 27, 1989, p. 22, from the US Environmental Protection Agency.
The shows the major causes of global warming, and lists them in order based on the percentage of global warming they have caused.
At the top is energy production, which far outranks any other source of global warming and accounts for more than half of all global warming.
Energy production creates greenhouse gases through the burning of fossil fuels. Until renewable, non-polluting methods of energy production are developed, energy production will likely remain at the top of this list.
Chlorofluorocarbons, or CFCs, rank second in the list. In recent times, public awareness about the dangers of CFCs has increased in some of the more developed countries. As a result, people are beginning to call for decreases in the consumption of products that produce CFCs.
Activity and Percent Contribution to Global Warming
Energy use and production 57%
Chlorofluorocarbons 17%
Agricultural practices 14%
Changes in land use 9%
Other industrial activities 3%
Source: C&EN, March 27, 1989, p. 22, from the US Environmental Protection Agency.
The shows the major causes of global warming, and lists them in order based on the percentage of global warming they have caused.
At the top is energy production, which far outranks any other source of global warming and accounts for more than half of all global warming.
Energy production creates greenhouse gases through the burning of fossil fuels. Until renewable, non-polluting methods of energy production are developed, energy production will likely remain at the top of this list.
Chlorofluorocarbons, or CFCs, rank second in the list. In recent times, public awareness about the dangers of CFCs has increased in some of the more developed countries. As a result, people are beginning to call for decreases in the consumption of products that produce CFCs.
Causes of Global Warming
“As human-caused biodiversity loss and climate disruption gain ground, we need to keep our sights clear and understand that the measure of a threat is not a matter of whether it is made on purpose, but of how much loss it may cause. It's an ancient habit to go after those we perceive to be evil because they intended to do harm. It's harder, but more effective, to "go after," meaning to more effectively educate and socialize, those vastly larger numbers of our fellow humans who are not evil, but whose behavior may in fact be far more destructive in the long run." (Ed Ayres, editor of Worldwatch magazine, Nov/Dec 2001)
Carbon Dioxide from Power Plants In 2002 about 40% of U.S. carbon dioxide emissions stem from the burning of fossil fuels for the purpose of electricity generation. Coal accounts for 93 percent of the emissions from the electric utility industry. US Emissions Inventory 2004 Executive Summary p. 10 Coal emits around 1.7 times as much carbon per unit of energy when burned as does natural gas and 1.25 times as much as oil. Natural gas gives off 50% of the carbon dioxide, the principal greenhouse gas, released by coal and 25% less carbon dioxide than oil, for the same amount of energy produced. Coal contains about 80 percent more carbon per unit of energy than gas does, and oil contains about 40 percent more. For the typical U.S. household, a metric ton of carbon equals about 10,000 miles of driving at 25 miles per gallon of gasoline or about one year of home heating using a natural gas-fired furnace or about four months of electricity from coal-fired generation.
Carbon Dioxide Emitted from Cars About 33% of U.S carbon dioxide emissions comes from the burning of gasoline in internal-combustion engines of cars and light trucks (minivans, sport utility vehicles, pick-up trucks, and jeeps).US Emissions Inventory 2006 page 8 Vehicles with poor gas mileage contribute the most to global warming. For example, according to the E.P.A's 2000 Fuel Economy Guide, a new Dodge Durango sports utility vehicle (with a 5.9 liter engine) that gets 12 miles per gallon in the city will emit an estimated 800 pounds of carbon dioxide over a distance of 500 city miles. In other words for each gallon of gas a vehicle consumes, 19.6 pounds of carbon dioxide are emitted into the air. A new Honda Insight that gets 61 miles to the gallon will only emit about 161 pounds of carbon dioxide over the same distance of 500 city miles. Sports utility vehicles were built for rough terrain, off road driving in mountains and deserts. When they are used for city driving, they are so much overkill to the environment. If one has to have a large vehicle for their family, station wagons are an intelligent choice for city driving, especially since their price is about half that of a sports utility. Inasmuch as SUV's have a narrow wheel base in respect to their higher silhouette, they are four times as likely as cars to rollover in an accident.
Methane While carbon dioxide is the principal greenhouse gas, methane is second most important. According to the IPCC, Methane is more than 20 times aseffective as CO2 at trapping heat in the atmosphere. US Emissions Inventory 2004 Levels of atmospheric methane have risen 145% in the last 100 years. Methane is derived from sources such as rice paddies, bovine flatulence, bacteria in bogs and fossil fuel production. Most of the world’s rice, and all of the rice in the United States, is grown on flooded fields. When fields are flooded, anaerobic conditions develop and the organic matter in the soil decomposes, releasing CH4 to the atmosphere, primarily through the rice plants. US Emissions Inventory 2004
Water Vapor in the Atmosphere Increasing Water vapor is the most prevalent and most powerful greenhouse gas on the planet, but its increasing presence is the result of warming caused by carbon dioxide, methane and other greenhouse gases. (See NOAA's National Climate Data Center (NCDC) FAQ page) Water vapor holds onto two-thirds of the heat trapped by all the greenhouse gases. As the Earth heats up relative humidity is able to increase, allowing the planet's atmosphere to hold more water vapor, causing even more warming, thus a positive feedback scenario. Because the air is warmer, the relative humidity can be higher (in essence, the air is able to 'hold' more water when its warmer), leading to more water vapor in the atmosphere, says the NCDC. There is much scientific uncertainty as to the degree this feedback loop causes increased warming, inasmuch as the water vapor also causes increased cloud formation, which in turn reflects heat back out into space.
Deforestation After carbon emissions caused by humans, deforestation is the second principle cause of atmospheric carbon dioxide. (NASA Web Site) Deforestation is responsible for 20-25% of all carbon emissions entering the atmosphere, by the burning and cutting of about 34 million acres of trees each year. We are losing millions of acres of rainforests each year, the equivalent in area to the size of Italy. The destroying of tropical forests alone is throwing hundreds of millions of tons of carbon dioxide into the atmosphere each year. We are also losing temperate forests. The temperate forests of the world account for an absorption rate of 2 billion tons of carbon annually. In the temperate forests of Siberia alone, the earth is losing 10 million acres per year.
“As human-caused biodiversity loss and climate disruption gain ground, we need to keep our sights clear and understand that the measure of a threat is not a matter of whether it is made on purpose, but of how much loss it may cause. It's an ancient habit to go after those we perceive to be evil because they intended to do harm. It's harder, but more effective, to "go after," meaning to more effectively educate and socialize, those vastly larger numbers of our fellow humans who are not evil, but whose behavior may in fact be far more destructive in the long run." (Ed Ayres, editor of Worldwatch magazine, Nov/Dec 2001)
Carbon Dioxide from Power Plants In 2002 about 40% of U.S. carbon dioxide emissions stem from the burning of fossil fuels for the purpose of electricity generation. Coal accounts for 93 percent of the emissions from the electric utility industry. US Emissions Inventory 2004 Executive Summary p. 10 Coal emits around 1.7 times as much carbon per unit of energy when burned as does natural gas and 1.25 times as much as oil. Natural gas gives off 50% of the carbon dioxide, the principal greenhouse gas, released by coal and 25% less carbon dioxide than oil, for the same amount of energy produced. Coal contains about 80 percent more carbon per unit of energy than gas does, and oil contains about 40 percent more. For the typical U.S. household, a metric ton of carbon equals about 10,000 miles of driving at 25 miles per gallon of gasoline or about one year of home heating using a natural gas-fired furnace or about four months of electricity from coal-fired generation.
Carbon Dioxide Emitted from Cars About 33% of U.S carbon dioxide emissions comes from the burning of gasoline in internal-combustion engines of cars and light trucks (minivans, sport utility vehicles, pick-up trucks, and jeeps).US Emissions Inventory 2006 page 8 Vehicles with poor gas mileage contribute the most to global warming. For example, according to the E.P.A's 2000 Fuel Economy Guide, a new Dodge Durango sports utility vehicle (with a 5.9 liter engine) that gets 12 miles per gallon in the city will emit an estimated 800 pounds of carbon dioxide over a distance of 500 city miles. In other words for each gallon of gas a vehicle consumes, 19.6 pounds of carbon dioxide are emitted into the air. A new Honda Insight that gets 61 miles to the gallon will only emit about 161 pounds of carbon dioxide over the same distance of 500 city miles. Sports utility vehicles were built for rough terrain, off road driving in mountains and deserts. When they are used for city driving, they are so much overkill to the environment. If one has to have a large vehicle for their family, station wagons are an intelligent choice for city driving, especially since their price is about half that of a sports utility. Inasmuch as SUV's have a narrow wheel base in respect to their higher silhouette, they are four times as likely as cars to rollover in an accident.
Methane While carbon dioxide is the principal greenhouse gas, methane is second most important. According to the IPCC, Methane is more than 20 times aseffective as CO2 at trapping heat in the atmosphere. US Emissions Inventory 2004 Levels of atmospheric methane have risen 145% in the last 100 years. Methane is derived from sources such as rice paddies, bovine flatulence, bacteria in bogs and fossil fuel production. Most of the world’s rice, and all of the rice in the United States, is grown on flooded fields. When fields are flooded, anaerobic conditions develop and the organic matter in the soil decomposes, releasing CH4 to the atmosphere, primarily through the rice plants. US Emissions Inventory 2004
Water Vapor in the Atmosphere Increasing Water vapor is the most prevalent and most powerful greenhouse gas on the planet, but its increasing presence is the result of warming caused by carbon dioxide, methane and other greenhouse gases. (See NOAA's National Climate Data Center (NCDC) FAQ page) Water vapor holds onto two-thirds of the heat trapped by all the greenhouse gases. As the Earth heats up relative humidity is able to increase, allowing the planet's atmosphere to hold more water vapor, causing even more warming, thus a positive feedback scenario. Because the air is warmer, the relative humidity can be higher (in essence, the air is able to 'hold' more water when its warmer), leading to more water vapor in the atmosphere, says the NCDC. There is much scientific uncertainty as to the degree this feedback loop causes increased warming, inasmuch as the water vapor also causes increased cloud formation, which in turn reflects heat back out into space.
Deforestation After carbon emissions caused by humans, deforestation is the second principle cause of atmospheric carbon dioxide. (NASA Web Site) Deforestation is responsible for 20-25% of all carbon emissions entering the atmosphere, by the burning and cutting of about 34 million acres of trees each year. We are losing millions of acres of rainforests each year, the equivalent in area to the size of Italy. The destroying of tropical forests alone is throwing hundreds of millions of tons of carbon dioxide into the atmosphere each year. We are also losing temperate forests. The temperate forests of the world account for an absorption rate of 2 billion tons of carbon annually. In the temperate forests of Siberia alone, the earth is losing 10 million acres per year.
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