Recent weather patterns have brought extreme heat to many parts of the world, but in most inhabited regions, it typically doesn’t become “too hot for people to live,” especially in dry climates. In these areas, our bodies can usually cool off through the evaporation of sweat. However, in regions where hot deserts meet warm oceans, dangerous heat and humidity can combine, posing serious health risks.
Regions like the Middle East, Pakistan, and India frequently experience deadly combinations of heat and humidity during summer heat waves. The humid air from nearby seas hampers sweat evaporation, preventing our bodies from cooling effectively. Hundreds of millions of people in these areas lack access to air conditioning, making the situation even more dire.
Wet Bulb Temperatures and Their Impact
Scientists measure the severity of heat and humidity using a “wet bulb thermometer,” which accounts for the cooling effect of evaporation. Wet bulb temperatures over 95°F (35°C) are particularly dangerous, as the human body cannot dissipate enough heat. During a severe heat wave in 2023, wet bulb temperatures soared in the lower Mississippi Valley, though not to fatal levels. In May 2024, Delhi, India experienced near-fatal wet bulb temperatures, resulting in several deaths from suspected heatstroke.
Role of Climate Change
Climate change, driven by the burning of carbon-based fuels like coal and gasoline, is exacerbating these extreme weather conditions. Carbon dioxide emissions trap heat in the atmosphere, leading to rising temperatures. As a result, dangerously hot and humid weather is spreading to new areas, including parts of the U.S. Gulf Coast and the irrigated deserts of the Southwest.
The impacts of climate change extend beyond heatwaves. Warmer temperatures increase water evaporation, drying out crops and landscapes and heightening wildfire risks. Rising ocean temperatures cause sea levels to rise, threatening to displace up to 2 billion people by 2100. The global economy could see a 25% reduction in incomes by the end of the century if carbon emissions continue unabated.
Path Forward with Clean Energy
While the outlook appears grim, there is hope. Transitioning from fossil fuels to clean energy sources like solar and wind can mitigate the effects of climate change. Significant progress in making clean energy affordable and reliable has been made over the past 15 years. Nearly every country has committed to combating climate change, aiming to prevent further damage.
By embracing clean energy, we can protect our planet and ensure a livable future, much like our ancestors improved their lives by adopting modern conveniences.