A growing concern over global warming is emerging as it threatens to expand areas around the world that are too hot for human habitation. Rising temperatures and humidity levels are pushing more people outside the ideal climatic conditions necessary for human physiology. Currently, about 600 million people live in regions beyond these optimal conditions, with each degree of future warming potentially adding another 10% of the global population.
Regions in North Africa and South Asia are particularly vulnerable due to their exposure and lack of adaptive infrastructure like air conditioning. Lower-income countries face significant challenges in adapting to rising temperatures, exacerbating existing health risks.
If global warming reaches 2°C above pre-industrial levels, the area unsafe for younger adults could triple to about six percent of the world’s landmass—equivalent to an area roughly the size of the United States. This expansion poses severe health risks as humans can only withstand certain combinations of heat and humidity before experiencing severe health issues like heat stroke or heart attacks.
By 2070, one-third of the global population may experience average annual temperatures greater than 29°C. This could lead to billions living outside their traditional climate niches by the end of this century if current trends continue. The increased heat will strain healthcare systems, reduce productivity, and exacerbate social suffering—especially in already vulnerable communities.
To mitigate these impacts, governments are urged to implement early warning systems and specific protection measures for vulnerable groups such as outdoor workers. Improving access to air-conditioned spaces and urban green areas can also help reduce long-term exposure. Policymakers must reassess their strategies focusing not just on temperature but also on humid heat as a major threat moving forward.