- This year the month of February was the hottest so far since 1901 in India. According to a study in The Lancet, published in July 2021, with two decades of data (2000-2019), more than five million people died on average each year worldwide because of extreme temperatures.
- The Sixth Assessment Report of the Intergovernmental Panel on Climate Change states that extreme heat events will grow with increasing global warming and that every increment of warming matters.
How much has temperature increased?
- A study by the Centre for Study of Science, Technology and Policy (CSTEP) on the historical climate in India shows that temperature in India has been steadily increasing during both summer and winter. The recorded increase in maximum and minimum temperature over 30 years (1990-2019) is up to 0.9ºC and 0.5ºC, respectively.
- Summer temperatures have increased by 0.5ºC to 0.9ºC in many districts in Punjab, Haryana, Uttarakhand, Uttar Pradesh, Bihar, Rajasthan, Gujarat, and the northeast.
- Likewise, winter temperatures have also increased by 0.5ºC to 0.9ºC in 54% of India’s districts, with higher levels of warming in the northern States compared to the southern States.
- This increasing heat is a cause of suffering and death in extreme cases. It undermines systems such as agriculture and other climate-sensitive sectors that support the livelihoods and well-being of people.
- A joint report by the International Federation of Red Cross and Red Crescent Societies (IFRC), the United Nations Office for the Coordination of Humanitarian Affairs, and the Red Cross Red Crescent Climate Centre on preparing for heatwaves state that an extreme-heat event that was likely to happen
- only once in every 50 years without the influence of humans on climate is now likely to happen five times with human-induced climate change in the same period. If the warming is under 2ºC, such events will occur 14 times; if the warming is kept under 4ºC, they will occur almost 40 times.
How much hotter can it get?
- Climate projections for the districts of India by the CSTEP study for a 30-year period of 2021-2050 show that the maximum temperature during summer will increase even under a ‘moderate emissions’ scenario.
- The increase is higher under higher emissions scenarios — likely to be greater than 2ºC and up to 3.5ºC in over 100 districts and 1.5-2ºC in about 455 districts.
- Even winter minimum temperatures are projected to increase by 0.5ºC to 3.5ºC in the future. While the highest warming of 2.5ºC to 3ºC is projected in fewer than 1% of the districts, an increase by 1ºC to 1.5ºC is projected in about 485 districts.
- It is clear that both summer maximum and winter minimum temperatures will increase in the future.
- This can affect the growth of plants, ecological systems, and even the carbon economy as the extreme variations in temperature between days and nights will affect the quality of the soil.
- The diurnal temperature range (DTR) — the variation between high air temperature and low temperature during a single day — is also changing.
- A December 2020 study supported by the Department of Science and Technology reported an alarming decline in DTR between 1991 and 2016 over the north-west parts of the Gangetic plain, and central India agro-climatic zones.
- This decline signifies an asymmetric increase in the minimum temperature compared to the maximum, which in turn increases the risk of heat stress.
- This also leads to drought, crop failure, and higher morbidity and mortality. The joint report by IFRC and others also state that in the near future, heat waves could meet and surpass the human threshold to withstand them physiologically and socially, leading to large-scale suffering, death, and migration.
- From an urban perspective, the combined effects of warming and urbanisation will cause a significant increase in the number of people at risk of extreme heat.
- According to a 2019 International Labour Organization report, India is expected to lose 5.8% of working-hours in 2030 due to heat stress.
- The loss in agriculture and construction sectors will be 9.04%, which translates to 34 million full-time jobs.
- The July 2021 study suggests that future death rates caused by extreme heat could be staggeringly high by the end of the century, which is comparable in magnitude to all cancers or infectious diseases.
What should be done?
- More than ever, it is imperative that States step up and share responsibility with other stakeholders to implement the Sendai Framework for Disaster Risk Reduction through improved early warning systems, creation of public awareness, and formulation of heat action plans.
- In addition, we also need to consider innovative strategies to combat extreme heat, such as emergency cooling centres (similar to the ones in Toronto and Paris); survival guides that are strategically displayed to survive extreme heat or heat waves (like in Athens);
- white roofs (Los Angeles); green rooftops (Rotterdam); self-shading tower blocks (Abu Dhabi); and green corridors (Medellin).
- But most of all, it is crucial we prepare district-level heat hotspot maps so that different departments of a State and/or district can design long-term measures to reduce deaths due to extreme heat.
SOURCE: THE HINDU, THE ECONOMIC TIMES, PIB