Three out of four people in danger due to deadly heat, by 2100, scientists warn

Heatwaves are becoming increasingly problematic and if we look at the recent events in Portugal, United Kingdom and the United States, it is easy to understand the new dire warnings regarding the deadly heat coming from scientists. 

A new study published in the journal Nature offers an even grimmer perspective stating that by 2100, if the current trend continues, three out of four people will be in danger due to deadly heat.

Scientists conducted a global analysis of documented lethal heat events to identify the climatic conditions associated with human death and then quantified the current and projected occurrence of such deadly climatic conditions worldwide. What they found was that around 30% of the world’s population is currently exposed to climatic conditions exceeding this deadly threshold for at least 20 days a year.

In the long run, things look even bleaker. If the global community does not find the ways and means to reduce the greenhouse gas emissions, the consequences will be deadly.

“By 2100, this percentage is projected to increase to ∼48% under a scenario with drastic reductions of greenhouse gas emissions and ∼74% under a scenario of growing emissions. An increasing threat to human life from excess heat now seems almost inevitable, but will be greatly aggravated if greenhouse gases are not considerably reduced,” the study warns.

What makes matters much more complicated is that deaths due to heat are often underdiagnosed because exposure to extreme heat often results in the dysfunction of multiple organs, which can lead to misdiagnosis.

Also, mortality data from heat exposure are sparse and have not been analysed in a consistent manner. So the true effects of climate change and the impact it has on human life is not yet well documented.

The new study, coordinated by Camilo Mora has used extensive data in order to correctly assess the global risk of deadly heatwaves.

Looking at the models, the study also points out that while temperatures will mostly go up at higher latitudes, people in the tropical regions will be disproportionately affected because of their exposure to year-round warm temperatures and higher humidity, and the area requires less warming to cross the deadly threshold.

The models presented by the new analysis show that under the different scenarios, the areas that will suffer the most from deadly heatwaves are Central Africa, Northern Latin America, Southern United States, Northern Australia and Southern Asia.

And the effects of heat could be exacerbated, the scientists say, as the population is growing older, becoming more vulnerable to temperature spikes. Also, the increased urbanization will drive up the heat-island effect.

The researchers are asking for urgent measures in order to limit the population exposure to deadly heatwaves and a reduction in greenhouse gases, to curtail the temperature rise.