Delhi and Mumbai's mean annual temperature will be five degrees Celsius higher in the 2080-99 period as compared to the 1995-2014 period if global CO2 emissions double by 2050, according to Greenpeace India's new heatwave projections based on Intergovernmental Panel for Climate Change's sixth assessment report.
The national capital's annual maximum temperature (the median of June month record from 1995 to 2014) stands at 41.93 degrees Celsius. It will leap to 45.97 degrees Celsius in the 2080-99 period and can go up to 48.19 degrees Celsius in "some extreme years", the NGO said in a report.
A recent heatwave in Delhi saw the maximum touching 43.5 degrees Celsius on April 29, which is well above the average maximum temperature for the month.
An analysis of the historical daily temperature for April from 1970 to 2020 shows that only four years have recorded a value higher than 43 degrees Celsius, it said. Mumbai's mean annual temperature will be five degrees Celsius higher in the 2080-99 period as compared to the 1995-2014 period and the annual maximum temperature will increase from 39.17 degrees Celsius at present to 43.35 degrees Celsius, the report said.
Chennai will be four degrees Celsius warmer than now on average with a projected mean annual temperature of 31 degrees Celsius. Its annual maximum temperature will increase from 35.13 degrees Celsius at present to 38.78 degrees Celsius in the 2080-99 period.
Such a drastic and rapid increase in temperature will mean India will experience more unprecedented and prolonged heatwaves, extreme weathers, increased hospitalisations and irreparable damage to agriculture and wildlife risking food and nutritional security, Greenpeace India said.
"Heatwaves are fatal for public health and the economy. It also puts ecosystems at risk. We have enough science to link such extreme weather events to climate change. Unfortunately, if we do not act now, the threat is only going to increase in frequency, duration and magnitude, said Avinash Chanchal, Campaign Manager, Greenpeace India.
Inland cities are at a higher risk of heatwaves in the absence of regulation by oceans and a higher temperature range than coastal areas. The impaling temperature rise is expected to severely impact citizens particularly in cities like Delhi, Lucknow, Patna, Jaipur and Kolkata which share similar temperature patterns, he said.
Unfortunately, it will be the vulnerable communities who will face the crisis in its worst form. The most vulnerable populations, including the urban poor, outdoor workers, women, children, senior citizens, sexual minorities etc are at a significantly greater risk, as they lack adequate access to protective measures, Chanchal said.
The Intergovernmental Panel on Climate Change (IPCC) is the United Nations body for assessing the science related to climate change.
Its sixth assessment has been published in three parts with the first in August 2021, the second in February 2022, and the third in April 2022.