A new study has warned that up to 2.2 billion people in India’s Indus Valley and Pakistan could be exposed to extreme heat beyond human tolerance by the end of the century. The findings warned that warming of the planet beyond 1.5 degrees Celsius (C) above preindustrial levels will have a devastating effect on human health across the planet.
The study, published in Proceedings of the National Academy of Sciences, revealed that if global temperatures rise by 1°C or more than the current levels then every year, billions of people will experience extreme heat and humidity wherein they won’t be able to naturally cool themselves, a press statement explains.
After a certain level of heat and humidity, humans begin to experience heat-related health problems such as heat strokes or heart attacks.
In 2015, 196 nations signed the Paris Agreement to limit worldwide temperature increases to 1.5°C above pre-industrial levels. The interdisciplinary research team modelled global temperature increases ranging between 1.5°C and 4°C — considered the worst-case scenario where warming would begin to accelerate — to identify regions where warming would lead to heat and humidity levels that exceed human limits, the statement explains.
“To understand how complex, real-world problems like climate change will affect human health, you need expertise both about the planet and the human body,” co-author W. Larry Kenney said in the statement.
The findings indicate that if global temperatures increase by 2°C above pre-industrial levels, the 2.2 billion residents of Pakistan and India’s Indus River Valley, one billion people living in eastern China and the 800 million residents of sub-Saharan Africa will annually experience several hours of heat that are beyond human tolerance.
The regions would mainly experience high-humidity heatwaves. Heatwaves with higher humidity can be more harmful as the air is unable to absorb excess moisture, limiting sweat evaporation from human bodies. According to the press statement, if the warming continues to 3°C above pre-industrial levels, then the heat and humidity levels will affect the Eastern Seaboard and the middle of the United States — from Florida to New York and from Houston to Chicago. South America and Australia would also experience extreme heat.
As the atmosphere gets warmer, people sweat, and more blood is pumped to their skin to maintain their temperatures but at certain levels, these adjustments are not sufficient, and body core temperature begins to rise. If there is no way to cool down, then this can lead to exhaustion,
To stop temperatures from increasing, researchers suggest that it’s crucial to reduce the emission of greenhouse gases, especially the carbon dioxide emitted by burning fossil fuels. If these changes are not made, middle-income and low-income countries will suffer the most, they added.