Can we beat the heat — or is this the beginning of the end?

Heat kills. It debilitates. It slows our brain and reduces our cognitive functions. During the day, it makes outdoor work difficult to impossible. At night it makes it harder to sleep, which in turn contributes to poor health and cognitive fatigue. As temperatures rise, heat and lost sleep along with carbon dioxide levels together could cut our strategic decision-making skills in half by the end of the century.

There’s a limit to how much humans can tolerate — a combination of heat and humidity beyond which our bodies can’t survive. While it is sometimes difficult to diagnose heat deaths, we know that the European heat wave of 2003 caused 70,000 premature deaths beyond those expected in normal times and temperatures.

Acclimatization may allow some to adapt to higher temperatures. But the rapid increase in heat extremes in regions with no prior history of them will test our collective ability to adapt, especially as global warming shifts climates out of the range that nurtured the development of human civilization. No one will be able to adjust to the coming heat if we don’t stop the climate pollution that is already killing far too many people, usually the young, old and vulnerable — including the poor who live and die so commonly in the hottest part of a building that these are known as “top floor deaths.”

Heat and drought and other climate impacts also hammer our crops and even kill cattle, as recently seen in Kansas. This is already pushing up the price of food and contributing to our current inflation, through “heatflation.”

We now see the future of climate change more clearly because it’s already here. Punishing heatwaves are roaming the planet, from the U.S., to India and South Asia, to China and Europe: global warming is making them more frequent, more severe and longer lasting. 

But if the climate impacts are clearer and more certain, so are the climate solutions.

A recent paper we co-authored with others in the “Proceedings of the National Academy of Sciences” confirms that the best — and so far the only known — way to slow warming in the next decade or two, is to cut methane and the other short-lived super climate pollutants: hydrofluorocarbon refrigerants (HFCs), black carbon (soot) and ground-level ozone (smog).

It is also essential to decarbonize the energy system as fast as possible to cut emissions of carbon dioxide by shifting to clean energy. However, this strategy alone is not able to slow warming until 2050 and then only by a modest 0.1 degrees Celsius. By contrast, cutting the super climate pollutant methane can avoid nearly 0.3 degrees Celsius by the 2040s.

Slashing all the super pollutants can reduce global warming four times as much by 2050 as aggressive decarbonization, slowing the rate of warming by half worldwide and two-thirds in the Arctic.

We need to win two races to defeat the heat: a sprint to cut the super pollutants in the next decade, and a marathon to decarbonize by 2050 or sooner. That would give us a chance to slow self-reinforcing feedbacks that are causing the planet to start warming itself beyond the heat humans are adding. Failure means breaching the internationally accepted 1.5 degrees Celsius guardrail within a decade and facing a series of irreversible tipping points with potentially catastrophic impacts.

Other actions can help keep us safer during heatwaves. Shade trees can cut peak temperatures by several degrees Celsius, helping to offset the extra heating that occurs in cities. New white roofs can be up to 36 degrees Celsius (50 to 65 degrees Fahrenheit) cooler in the afternoon sun than a dark one. Researchers found that adding street trees and painting roofs lighter colors in Los Angeles would save one in four lives otherwise lost to extreme heat events. Reflective concrete rather than blacktop asphalt also helps.

Then there is air conditioning (AC), which can keep us cool so our bodies and brains function at their normal capacity and prevent vulnerable populations from dying in an intense heatwave. Keeping classrooms in the U.S. cool so kids can learn without sweltering is expected to cost an added $1.5 billion each year.  Some argue that access to AC is a human right, while prisoners in Texas argued that lack of it constituted “cruel and unusual” punishment.

But AC is a double-edged sword.  It uses a tremendous amount of energy — half or more of all electricity during a heat wave — mostly still generated by fossil fuels. So, it feeds a vicious cycle of warming from both its voracious electricity demand and the super climate polluting HFC refrigerants it uses.  

As the demand for AC surges, it is essential to ensure that only the most efficient units, using only climate-friendly refrigerants, are sold. Low-efficiency ones using super climate pollutant refrigerants are energy vampires that suck electricity from the grid, contributing to brownouts and blackouts when demand soars. Electricity use in Texas is expected to break records again this week, stressing the grid and putting at risk those depending on AC to survive.

The August 2020 Californian heatwave caused an electricity shortfall of two gigawatts and rolling blackouts, with the California Energy Commission estimating that cooling devices — primarily air conditioning — accounted for about 45 percent of the total strain on the grid. We estimate that replacing AC systems older than 15 years in California with energy-efficient ones would save four gigawatts of peak electricity, double the 2020 shortfall. And replacing ACs with efficient heat pumps would not only conserve electricity but could save U.S. households over $13 billion on heating bills annually.

Inefficient ACs are marketed to the poor as low-cost, but the added energy it takes to run them makes that a lie.  They also are being dumped in Africa and other developing countries, stealing energy that should be deployed to development.

Meanwhile, extreme heat is shattering records across the planet with triple digit highs in London and unusually hot early season extremes in India and Pakistan and the American Southwest.  We’re about to find out if we’re like the frog put in a pot of water that warms slowly and thus is lulled unto its death, or one dropped into the already too hot pot that quickly jumps out.  If we wait any longer, a little more warming — thank you Sen. Joe Manchin (D-W.Va.) who just squashed climate action in the Senate — and a little more impairment of our strategic decision-making skills may even make us forget that we once had a chance to jump.

Durwood Zaelke is president of the Institute for Governance & Sustainable Development (IGSD) in Washington, D.C. and Paris, as well as an adjunct professor at the University of California, Santa Barbara Bren School of Environmental Science & Management.

Gabrielle Dreyfus, Ph.D., is chief scientist at IGSD and an adjunct professor at Georgetown University.