Heatwaves linked to man-made climate change
Part of: Prelims and GS-III: Climate Change
Context: The three millimetre rise in sea level could drive a greater number of extreme climate events such as floods that could devastate coastal India, warns scientist. However, nature-based solutions such as increasing forest area could be done as part of India’s climate adaptation program.
- India is gripped in the throes of a long spell of heatwaves and there is compelling evidence that a significant portion of it is due to human-induced climate change.
Health Impacts of Heat Waves
- The mortality rates for extreme weather events are on a decline but rising significantly for heatwaves and lightning events. Heatwaves have now become the second most disastrous event (after lightning) linked to mortality.
- Heatwaves affect work productivity, by reducing performance and increasing heat-related illness. A decline of 30-40% in the work performance is projected over India by the end of the century due to the elevated heat stress levels
What is causing this?
- Due to an anti-cyclone over the Arabian Sea, winds are moving in the clockwise direction creating an area of subsidence where hot, westerly winds are blowing.
- There are clear skies so there is abundant radiation. This has led to this unusually intense heat wave spell over large parts of the country. This dry, hot weather is likely to impact both quality and yield of wheat in many parts of north India
- During an anti-cyclone, air pressure is high on the surface, causing the air above it to come down. This air warms up as it comes down on account of high pressure. The outward hot winds caused by this are ranging as far as Odisha and West Bengal.
- But early next week, the western disturbance will likely put an end to this anti-cyclone, pushing moisture-laden winds in from both the Arabian Sea and the Bay of Bengal, a phenomenon that will likely reduce temperatures through most of the plains.
- In some regions experiencing heatwaves, it is not just about the high temperatures but the accompanying rise in humidity too that matters. Sustained heatwaves can be dangerous, especially when combined with high levels of humidity. If the air has high levels of humidity along with the heat, the body stops sweating and becomes unable to regulate the internal temperature. This can result in a heat stroke leading to multiple organ failure and deaths
First Aid for heat stroke:
While waiting for the paramedics to arrive, initiate first aid with the aim to lower the body temperature.
- Move the person to an air-conditioned environment or at least a cool, shady area and remove any unnecessary clothing.
- Fan air over the patient while wetting his or her skin with water from a sponge or garden hose.
- Apply ice packs to the patient’s armpits, groin, neck, and back because these areas are rich with blood vessels close to the skin, cooling them may reduce body temperature.
- Do not use ice for older patients, young children, patients with chronic illness, or anyone whose heat stroke occurred without vigorous exercise.
Increased exposure to heatwaves needs a policy response, nationally and globally. Long term measures should be taken to address the issue in the wake of global warming and climate change:
- Afforestation drives to increase green cover.
- A further reduction in the share of coal in the energy mix through sustained support for renewable energy, particularly solar photovoltaic, must form the cornerstone of national policy
- It is vital that India gets more ambitious about cutting back on carbon emissions, even as
- This must be matched by a shift away from use of fossil fuels for transport, and the induction of more electric vehicles.