General Studies Paper 1
Context: According to the latest report of the Intergovernmental Panel on Climate Change the world is currently at around 1.1°C of warming whereas the warming trends over the Indian region are very different.
- The annual mean temperature of the world is known to have increased by 1.1 degree Celsius from the average of the 1850-1900 period.
- An assessment of climate change over the Indian subcontinent, published by the Ministry of Earth Sciences in 2020, said annual mean temperatures had risen by 0.7 degree Celsius from 1900.
- This is significantly lower than the 1.59 degree Celsius rise for land temperatures across the world.
- It could give the impression that the problem of climate change over India was not as acute as other parts of the world.
- Temperature is the measure of the average heat or thermal energy in a substance.
- Air and water temperatures are primarily determined by the amount of sunlight that is absorbed by the surface of the Earth, and the amount of heat that is re-radiated in the atmosphere by the greenhouse gases.
- Atmospheric and ocean circulation redistribute heat across the surface of the Earth and shape regional temperature patterns.
Are Warming Trends Different Across the Globe?
- Average of Warming Temperature: The planet as a whole has warmed by 1.1 degree Celsius compared with pre industrial times but, this is just the average. Different regions have seen very different levels of warming.
- Arctic Region:The polar regions, particularly the Arctic, have seen significantly greater warming. The Arctic region has warmed at least twice as much as the world average. Its current annual mean temperatures are about 2 degrees Celsius higher than pre-industrial times.
- The ice cover in the Arctic is melting, because of which more land or water is getting exposed to the Sun. Ice traps the least amount of heat and reflects most of the solar radiation when compared with land or water.
- More recent research suggests that the higher warming in the polar region could be attributed to a host of factors, including the albedo effect, changes in clouds, water vapour and atmospheric temperatures.
- The warming in the polar regions account for a substantial part of the 1.1 degree Celsius temperature rise over the entire globe.
Factors that Affects the Warming of Regions
- Altitude: The increase in temperatures is known to be more prominent in the higher altitudes, near the polar regions, than near the equator.
- This is attributable to a complex set of atmospheric phenomena, including heat transfers from the tropics to the poles through prevailing systems of air circulation.
- Albedo effect: Another prominent cause is what is known as the albedo effect, or how much sunlight a surface reflects. The ice cover in the Arctic is melting, because of which more land or water is getting exposed to the Sun.
- Ice traps the least amount of heat and reflects most of the solar radiation when compared with land or water.
- Aerosols: Aerosols refer to all kinds of particles suspended in the atmosphere. These particles have the potential to affect the local temperature in multiple ways.
- Many of these scatter sunlight back, so that less heat is absorbed by the land. Aerosols also affect cloud formation.Clouds, in turn, have an impact on how much sunlight is reflected or absorbed.
- Land-Ocean Atmospheric Interactions: Variation in the amount of solar radiation absorbed, and the amount of heat re-radiating from Earth’s land and oceans results in temperature differences in air over different types of terrain.
For example, sea breezes occur because land heats up and cools down faster than water, so that the land is warmer during the day and breezes flow from the sea inland, but the ocean is warmer than land at night, so the wind blows from land to sea