How Extreme Heat Will Eventually Make Much of the Earth Completely Unlivable

Maya May, the host of the PBS series Weathered, warned that much of Earth will become unlivable in the future due to extreme heat and the significant role humidity plays in this process. She also spoke with extreme heat researcher Casey Ivanovich of the NASA Goddard Institute for Space Studies to learn more about how we can protect ourselves.

Heat is the deadliest weather hazard in the U.S. and many places around the world, and it’s only getting worse. The most deadly heat waves so far have been dry heat waves. But a new threat is rising: humid heat waves, aka wet-bulb events. Scientists have identified wet-bulb temperatures where sweat can’t evaporate fast enough to cool the human body. And once this threshold is crossed, it doesn’t matter how much shade or water you have: you won’t survive without environmental cooling like air conditioning.

As of this date, NASA confirmed that 2024 was the hottest year on record.