The term ‘Global Warming’ was given by Wally Broecker. Global warming is a phenomenon which refers increase in average temperature of the atmosphere of the earth over a long period of time. Before the pre-industrial revolution, the average atmospheric temperature of the earth was 15°C. Currently it is 16.6°C. In last 100 years the increment is 0.76°C-0.80°C.
Possible Effects of Global Warming
There are some possible effects of Global warming:
1. Effects on Weather and Climate
- The average temperature has increased by 0.8°C around the world since 1880. The average temperature of the earth may increase by 1.4 to 5.8°C by the year 2100 from the 1990 level.
- Glaciers & mountain snow are rapidly melting. Example, Montana’s glacier national park now has only 25(in 2010) glaciers versus 150 in 1910.
- Warming of the atmosphere will considerably increase its moisture carrying capacity. While the troposphere warms up, the stratosphere will cool down.
- This would cause wide spread changes in precipitation pattern due to change pattern of air-mass movement. Precipitation is expected to increase at higher latitudes in both summer and winter because temperature changes are expected to be most marked in the region of middle and higher latitude.
2. Effects on Sea Level Change
- Sea level has been raised by 1 to 2 mm per year during the 20th Century.
- It is predicted that by the year 2100, the global mean sea level can increase up to 0.88 m over the 1990 level.
- Arctic ice is rapidly melting and polar bears and indigenous cultures are suffering from sea-ice loss.
- Many small islands are in danger to be submerged in near future.
3. Effects on range of species distribution
- Global warming is likely to shift the temperature ranges and, therefore, would affect altitudinal and latitudinal distribution pattern of an organism.
- Coral reefs are highly sensitive to small change in water temperature, suffered the worst bleaching rate upto 70%.
- With an increase in global temperature by 2 to 5°C during the 21st century, the temperate region vegetation may shift to 250-600 km towards the pole.
- Since trees are sensitive to temperature stress, a rapid rise in temperature may cause large scale death of trees and their replacement by scrub vegetation.
4. Effects on Food Production
Increased temperature will cause an eruption of plant diseases and parts, explosive growth of needs and increased basal rate of respiration of plants.
How to Reduce Global Warming
- Reducing the emulsion of greenhouse gases by limiting the use of fossil fuels.
- Increasing vegetation cover.
- Minimizing the use of N2 fertilizer in agriculture for reducing N2O emission.
- Developing substitutes of CFCs.
Q. What are the consequence of global warming?
Ans. See section (Possible Effects of Global Warming) for an answer.