Unless the world curbs greenhouse gas emissions significantly, extreme heat could become a major global killer by the end of this century, equalling death rates for all infectious diseases combined, including tuberculosis, HIV and malaria.
In the largest international study till now on health and financial impacts of temperature-related deaths, the Climate Impact Lab said climate change’s effect on temperatures could raise global mortality rates by 73 additional deaths per 100,000 people in 2100 under a continued high emissions scenario, compared to a world with no warming.
Climate change has led to heat waves that are longer, more intense and more frequent. Researchers say the increasing heat will take a worsening toll in human lives as temperatures continue to rise.
“Previous research has significantly understated climate change damages due to mortality,” said the study published by the National Bureau of Economic Research. “The mortality damages we estimate in 2100 account for 49% to 135% of total damages across all sectors of the economy according to leading IAMs.”
IAMs, or integrated assessment models for climate change refer to a broad category of research approaches in climate change.
The perils of extreme heat are also grossly unequal. The poor and marginalised are likely to be much more vulnerable to extreme heat. People in countries such as Ghana, Sudan, Pakistan and Bangladesh may face an additional 200 or more deaths compared with the global average of 73 per 100,000 people.
“The data show that poor communities don’t have the means to adapt, so they end up dying from warming at much higher rates,” said co-author Tamma Carleton of University of California.
“In poor hot countries, the heat may be even more threatening than cancer and heart disease are today,” said Michael Greenstone of the University of Chicago, another co-author of the study.