Key Takeaways
  1. Average annual temperatures in India are projected to increase from about 24°C to 28°C by the end of the century under continued high-emission scenario.
  2. There is likely to be eight times more extremely hot days, with temperatures above 35°C, increasing from 5.1 per year in 2010 to 42.8 per year in 2100.
  3. National Capital Delhi is likely to face 22 times more extremely hot days and more than 23,000 climate-related deaths annually by 2100 under continued high-emission scenario.
  4. Himalayan states are projected see the highest increase in average summer temperatures: Jammu & Kashmir (+5.1°C), Himachal Pradesh (+4.4°C) and Uttarakhand (+4.1°C).
  5. By 2100, Meghalaya (28.3°C) could be warmer than what Maharashtra (28.0°C) is at present. Similarly, by 2100, Arunachal Pradesh (27.2°C) could be as hot as Goa (27.5°C) is currently.
  6. The number of extremely hot days in Odisha are likely to rise by 30 times of what it is today by 2100, the highest increase in hot days among all the states.
  7. Punjab is projected to experience 85 extremely hot days, the highest amount of hot days among all the states.
  8. By 2100, around 1.5 million more people are projected to die each year as a result of climate change—at a rate as high as the death rate from all infectious diseases in India today.

Continued high emissions of greenhouse gases are projected to lead to a 4°C rise in average annual temperature in India by 2100, with the average number of extremely hot days around the country over 35°C likely to increase by more than eight times per year from 5.1 (in 2010) to 42.8, shows a new study released today at an event at the UChicago Center in Delhi. The study is the first in a series of findings estimating the human and economic costs of climate change and weather shocks in India, conducted by the Climate Impact Lab in collaboration with the Tata Centre for Development at UChicago.

With the number of extremely hot days increasing, 16 out of the 36 states and union territories are projected become hotter than Punjab, which is currently the hottest state in India with an average annual temperature just below 32°C (as of 2010). Punjab is expected to continue to be India’s hottest state in 2100, with average annual temperature around 36°C.

Odisha, however, is projected to top the list when it comes to highest increase in the number of extremely hot days, rising from 1.62 in 2010 to 48.05 by 2100. In addition, Haryana, Rajasthan and Delhi are also likely to register significant increases in the number of extremely hot days. While Delhi is projected to experience 22 times more extremely hot days (three to 67) by 2100, Haryana (20 times), Punjab (17 times) and Rajasthan (seven times) will not be much better off.

The spike in average summer temperature and number of extremely hot days has an impact on mortality, the study finds. Six states, Uttar Pradesh (402,280), Bihar (136,372), Rajasthan (121,809), Andhra Pradesh (116,920), Madhya Pradesh (108,370), and Maharashtra (106,749) are estimated to contribute 64 percent of the total excess deaths—more than 1.5 million deaths each year in all—due to temperature rises caused by climate change.

Background

To establish the relationship between extreme heat and mortality, Climate Impact Lab researchers collected the largest data set ever compiled on human mortality around the world, including India. Mortality-temperature relationship estimates were used to generate projections of the future impacts of climate change on mortality rates.

The study looked at two different scenarios for estimating temperature rise, increase in number of extremely hot days and mortality risk. The first scenario (RCP 4.5) is based on the assumption that carbon emissions will peak around 2040, and by 2100, atmospheric CO2 equivalent concentration will reach 540 ppm. The second scenario (RCP 8.5) assumes that emissions will continue to rise throughout the 21st century and atmospheric CO2 equivalent concentration will reach 940 ppm by 2100. According to the U.S. National Oceanic and Atmospheric Administration (NOAA), the global atmospheric CO2 concentration was 410 ppm on January 1, 2019.

The projections in this report represent the first empirically-derived estimate of the impacts of climate change for a single sector of the Indian economy. This is the first in a series of analyses that will apply similar levels of detail to data-driven projections of other sectors of the economy like agriculture, and energy system, which will enable the calculation of full benefits to India of choosing a path of reduced reliance on fossil fuels.

About Tata Centre for Development at UChicago

The Tata Centre for Development (TCD) at the University of Chicago works to identify novel solutions to India’s most pressing development challenges and ensure that these ideas are translated into outcomes that improve people’s lives. TCD targets research projects that will contribute new, evidence-based solutions to difficult development problems whose insights can affect change in the real world. Representing the joint work of the Tata Trusts and the University of Chicago, TCD asks difficult questions, challenges conventional thinking and creates a new model for impact in India.

About Climate Impact Lab

The Climate Impact Lab is a collaboration of more than 20 researchers from the Global Policy Laboratory at the University of California, Berkeley, the Energy Policy Institute at the University of Chicago (EPIC), Rhodium Group, Rutgers University, and the London School of Economics. Together, they are linking state-of-the-art climate modelling, economic statistics, and big data analytics to build the world’s most comprehensive body of research quantifying the impacts of climate change around the globe. EPIC provides core financial and administrative support for the Lab. Learn more at impactlab.org