Climate Change

CLIMATE CHANGE

Carbon dioxide (co2), water vapour, methane, nitrous oxide and a few other gases are called green house gases and their increasing concentration in the atmosphere is the cause of anthropogenic climate change. The green house effect occurs because these specific gases act like a green house, they let solar radiation into the planet, but trap the resulting heat, specifically the green house gases are transparent to incoming ultra-violet radiation from the sun which passes through the atmosphere and into the earth. The earth is warmed by this radiation and in response radiates infrared energy back into space. These atmospheric gases absorb some of the out-going infrared radiation, trapping the energy in the atmosphere and thereby warming the earth.

These effects of greenhouse gases are often summarised as global warming, they not only change the temperature but also many other aspects of earths chemical climate and biological processes. The rise in greenhouse gases will raise land and ocean surface temperatures with innumerable complex effects on other aspects of climate including rainfall, storms, ocean circulation, wind patterns and more

According to the Stern Review on climate change, ocean levels are likely to rise for two reasons; thermal expansion of sea water as the ocean warms and melting and disintegration of the great ice sheets of Greenland and Antarctica. Rising ocean levels will submerge coastal areas, lead to higher sea surges during storms and cause saline infiltration of coastal groundwater aquifers, some small islands may be completely submerged.

Secondly, changes in climate and chemistry of various habitats are likely to provoke large scale extinction of vulnerable species with limited habitat ranges or limited mobility in the face of changing climate. Polar bears and alpine species for example, may be the first ones to go, since they will have no place to escape to as temperatures increase.detailed studies show that millions of species, large and small, will be threatened with extinction.

Thirdly, many infectious diseases are regulated by climate, including average temperature and precipitation. The climate effects are often complex and often interact. A decline in rainfall, for example, can intensify certain vector-borne diseases by pushing animal species into more limited watering and breeding areas. The geographic range in which diseases are transmitted may be expanded because of higher temperatures.

Higher temperatures, shifting growing seasons, changing species composition and altered rainfall patterns could locally modify agricultural productivity, some areas could experience a rise in productivity but others, particularly in the warm and dry regions, and the adverse effects are likely to be substantial. Climate change, moreover, may interact with increased air pollution to result in even larger declines in crop productivity.

Climate