Global Warming and India

Context: According to a study published by the Ministry of Earth Sciences in 2020, annual mean temperatures in India have experienced a significant increase, although it is lower compared to the global average.

More on the News

• The study notes that this lower increase in temperatures should not be seen as an indication that the problem of climate change is less severe in India.
• Instead, it emphasizes the complex nature of global warming and explores various factors that help us understand the situation in India more comprehensively.

Introduction: The case of India’s slower heating than the rest of the world

• 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.
• But this increase, as can be expected, is not uniform. It varies in different regions and also at different times of the year. This single number denoting global temperature built on top of several layers of averages.
• Temperature rise over land is much higher than over oceans. Over land, the annual mean temperatures have risen by as much as 1.59 degree Celsius since preindustrial times. Oceans, in contrast, have warmed by about 0.88 degree Celsius.
• The warming trends over the Indian region are very different. 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.

Why is warming over India lower?

The lower warming over India can be attributed to several factors. They include the following:

• India’s tropical location: The increase in temperatures is known to be more prominent in the higher altitudes, near the polar regions, than near the equator or tropics.
  • The polar regions, particularly the Arctic, have seen significantly greater warming than others.
  • Greater warming in the polar regions 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 etc.
  • A majority of the global landmass is concentrated in the northern latitudes. In the tropics and along the equator, it is mostly oceans.
  • Land areas are also prone to faster, and greater, heating. Because of both these reasons — that lands heat up more, and most of the land is located in northern latitudes — the average warming over global land areas has become more pronounced.
  • For a country like India, located in the tropics, the deviation in temperature rise from the global average is not surprising.
• Land-water differential: Land areas tend to heat up faster and to a greater extent than oceans due to differences in their heat capacities.
  • As a result, the overall temperature rise over land areas globally is higher compared to that over oceans.
  • Since India is primarily located on the land, the relatively lower heating in India can be attributed to the fact that land areas generally experience more pronounced warming than oceanic regions.
  • However, longer-term enhanced heating trends over land have to be attributed to other, more complicated, physical processes involving land-ocean-atmospheric interactions.
• Impact of 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.
  • They scatter sunlight back, so that lesser 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.
  • Aerosol concentration over the Indian region is quite high, due to natural as well as man-made reasons.
  • Due to its location in the tropics and the arid climate, India is no stranger to dust.
  • But it also happens to be experiencing heavy pollution right now. Emissions from vehicles, industries, construction, and other activities add a lot of aerosols in the Indian region. A reduction in warming could be an unintended but positive side-effect.

Conclusion: Overall, the article emphasizes that the lower warming over India is not an indication that the problem of climate change is less severe. It highlights the complex nature of global warming and the need to consider regional variations and factors such as aerosols and geographical location when analyzing temperature trends.

Sharing is caring!