THE EFFECTS OF GLOBAL WARMNG

WHAT ARE THE EFFECTS OF GLOBAL WARMING?

The effects of global warming on the environment and human life are numerous and varied. Scenarios studied by the Intergovernmental Panel on Climate Change (IPCC) predict that global warming will continue and get worse much faster than was expected even in their last report. The IPCC reports attribute many specific natural phenomena to human causes. The expected long range effects of recent climate change may already be observed. Rising sea levels, glacier retreat, Arctic shrinkage, and altered patterns of agriculture are cited as direct consequences of human activities. Predictions for secondary and regional effects include extreme weather events, an expansion of tropical diseases, changes in the timing of seasonal patterns in ecosystems, and drastic economic impact. Concerns have led to political activism advocating proposals to mitigate, eliminate, or adapt to it.



PHYSICAL IMPACTS

EXTREME WEATHER
Increasing temperature is likely to lead to increasing precipitation but the effects on storms are less clear. Extratropical storms partly depend on the temperature gradient, which is predicted to weaken in the northern hemisphere as the polar region warms more than the rest of the hemisphere. Storm strength leading to extreme weather is increasing, such as the power dissipation index of hurricane intensity. Hurricane modeling has produced similar results, finding that hurricanes, simulated under warmer, high-CO2 conditions, are more intense, however, hurricane frequency will be reduced.
Worldwide, the proportion of hurricanes reaching categories 4 or 5 – with wind speeds above 56 metres per second has risen from 20% in the 1970s to 35% in the 1990s. Some studies have found that the increase in sea surface temperature may be offset by an increase in wind shear, leading to little or no change in hurricane activity. Increases in catastrophes resulting from extreme weather are mainly caused by increasing population densities, and anticipated future increases are similarly dominated by societal change rather than climate change.