A recent study shows that a half-degree rise in global temperatures could triple the land area deemed too hot for healthy adults to survive, posing severe risks to both younger and older populations. If warming reaches 2°C, about six percent of land, particularly in hot regions, would not sustain life, necessitating urgent climate action.
A recent evaluation by an international team led by King’s College London reveals that a half-degree increase in global temperatures could triple the amount of land deemed too hot for healthy adults to maintain a safe core body temperature. Specifically, if global warming reaches 2°C above preindustrial levels, about six percent of the Earth’s landmass—equivalent to an area almost the size of the United States—will become dangerously hot.
The report indicates that this rise in temperature will significantly escalates the risks of lethal heat conditions, particularly in extreme heat events. Currently, those over 60 years are at significant risk, with predictions suggesting that they would be vulnerable across roughly 35% of the planet’s land area if these warming thresholds are crossed. Last year marked the first instance where global temperatures reached 1.5°C above preindustrial averages, foreshadowing an ominous trend towards reaching 2°C by mid-century.
Dr. Tom Matthews, a Senior Lecturer in Environmental Geography at King’s College London and lead author of the study, underscores the dire implications of these findings, stating that prolonged exposure to extreme heat, even with hydration, can lead to fatal heatstroke. The study distinguishes between two critical heat thresholds: uncompensable, where the body temperature rises uncontrollably, and unsurvivable, where it can soar to fatal levels within hours.
The research compiled data from 1994-2023, highlighting breaches of human thermal tolerances—conditions above which the body cannot function. Currently, around 2% of land is too hot for younger adults, while over 20% impacts older adults. If warming increases to 4-5°C, older adults could see uncompensable temperatures over approximately 60% of Earth’s surface, thus broadening the threat to younger individuals in very hot regions.
Certain regions, particularly in Saharan Africa and South Asia, face the highest risks of surpassing these critical heat thresholds. Dr. Matthews emphasizes the necessity of understanding the potential impacts of future extreme heat and targeting mitigation efforts toward the most affected communities. The alarming potential of extreme heat at increased warming levels necessitates a commitment to interdisciplinary research to mitigate these hazards effectively.
Since 2000, heat-related fatalities have numbered over 260,000 during severe heat events, exemplifying the health crisis that extreme temperatures pose. Significant historical heat events, including 2003 in Europe with 72,000 deaths, continue to demonstrate the urgent need for decisive action in addressing climate change to protect vulnerable populations.
The study addresses the implications of rising global temperatures on human heat tolerance, focusing on critical temperature thresholds that could endanger the lives of older and younger adults alike. As global warming progresses, environmental scientists are increasingly concerned about the sustainability of outdoor living conditions, particularly under extreme heat scenarios. The differentiation between uncompensable and unsurvivable heat thresholds provides clarity in understanding the mortality risks associated with climate change.
The findings reveal alarming projections regarding climate-induced heat extremes and their potential to threaten human survival. With projections that up to 40% of global land may become compromised under continued warming, the urgent need for mitigation strategies is highlighted. Future research must prioritize understanding and addressing these escalating heat risks to safeguard vulnerable populations against the dire consequences of climate change.
Original Source: www.kcl.ac.uk
