The Effect Global Warming can said as the abnormal increase in the temperature of the environment due to continuous accumulation of gaseous pollutants. The earth gets shortwave radiation from the Sun and 1/3rd of the same is reflected and 2/3rd of the radiation is absorbed by the atmosphere, ocean, ice, land and biota. The abnormal increase in volume of greenhouse gases and consequent global warming affects the earth’s climate and its ecosystem. The effects of Global Warming are
1) Change in Sea Level:
If the amount of Carbon-di-oxide in the environment increases without any control, the sea level may increase up to 18-28 cms around the year 2030. At present the global sea levels are rising a few centimeters per decade. Two third of the rise in sea level is due to global warming and remaining one third is due to deforestation, draining of wetlands and large scale pumping of ground water.
Sea and Temperature:
Mean global temperature may rise by 1.4°C ± 0.7°C by the year 2030 and 2.1°C ± 0.8°C by the year. Mean global sea water level which has risen – cm in the last century may rise further by another 10 cms to 20 cms by 2025 and 50 cms to 200 cms by the year 2100. It will cause extensive flooding of low lying areas in the world. Entry of salt water makes land unsuitable for cultivation. Most of the plants and animals will become extinct because of rapid change in temperature.
Rise in sea level which may be due to the major changes such as:
(i) Thermal expansion of atmosphere
(ii) Mountain glaciers melting
(iii) Melting of Greenland ice sheets
(iv) Melting of Antarctic ice sheets.
2) Crop yield:
Carbon-di-oxide rise will result in the increase of yield of crops. However it will effect regional climate change and loss of ecosystem.
3) Water balance:
Water availability is likely to be more serious and perhaps more expensive to solve. In future the warmer world will have water crisis in some areas of the world and other areas will be wetter than today. Global warming may affect rain patterns and subsequently it may affect agriculture and ecosystem.
4) Scarcity of Water supply:
Rivers, lakes, streams and aquifers may shrink or even totally dry, which ultimately force the population to make migration to other areas.
5) Change in Forest:
Temperate and subarctic forests will get reduced to grasslands and shrub lands. Forest fire would add more Carbon-di-oxide to the atmosphere.
6) Reduction in bio-diversity:
Large scale deforestation would also cause extinction of species. Reduction in forest, wild life sanctuaries, wetlands, coral reefs lead to loss of biodiversity.
7) Weather extremes:
Continuous heat waves and droughts would become a regular problem in many areas. As the surface layer of sea water becomes warmer, hurricanes and typhoons would occur more frequently and blow more fiercely.
8) Threats to human health:
Global warming would disrupt supplies of food and water, displace many people and altering disease patterns. Tropical diseases like malaria, elephantiasis, yellow fever, dengue fever may spread from the tropical region to temperate zones.