Heat Waves in Europe and the US Reveal Climate Adaptation Limits

Just as a debilitating heat wave linked to thousands of deaths began to ease in Europe, a heat dome engulfed the central and eastern United States over the Fourth of July weekend. Americans from Texas to New York were left facing the same kind of sweltering weather their European counterparts had only just endured. As temperatures approached 110 degrees Fahrenheit in some places, organizers across a number of US cities made the call to cancel America 250 events and parades.

Neither heat wave was the first this year for Europeans or Americans. In March, an early-season heat wave gripped the western United States. Europe, meanwhile, has seen temperature records shattered dozens of times since May.

Pollution from burning fossil fuels is contributing to the increased incidence of heat waves, as more heat is being trapped in the atmosphere. The average global surface temperature is already more than 1.4 degrees Celsius (2.52 degrees Fahrenheit) above preindustrial levels. The more that number creeps up, the more often heat waves will occur, and the more severe they will become.

Arguably, the United States, with greater penetration of air conditioning, is better situated to withstand heat waves than Europe. Nearly 90 percent of US homes have air conditioning, compared to about 20 percent of European households. A history of mild summers meant most Europeans historically had no need for air conditioning, and high electricity prices made it something of a luxury for many. But while there remains some ideological hostility to air conditioning in some quarters, exigency will likely lead more Europeans to install A/C units or, better yet from a climate perspective, heat pumps, which are far more efficient and can both cool and heat a home.

Even though the worst effects of the current heat wave may have passed in Europe, another may be on the way. There are also now heightened wildfire risks with blazes underway throughout France and Spain among other countries. These could prove catastrophic and test governments in the weeks to come as they have increasingly in previous years, forcing the mobilization of thousands of firefighters to prevent the loss of lives and property and to contain blazes that foul the air.

While there is greater access to air conditioning in the United States than in Europe, prevalence is not uniform across the country. Cooler conditions in the Northeast and Northwest historically led to lower rates of air conditioning. But that is changing. Today, about 85 percent of households in the northeast United States have some form of air conditioning, even if for many houses it is only window units. Still, A/C penetration remains lower in the Northwest, which was why a heat wave in Washington and Oregon in 2021 led to several hundred deaths.

Even with access to air conditioning, escalating costs of electricity, fueled in part by rising data center demand, may make it difficult for low-income Americans to afford cooling their homes as much as they would like. And those unconcerned with energy costs are still subject to the vulnerability of electricity grids, which are increasingly at risk of power outages during demand spikes.

While the United States thus far this year has escaped without a major power outage, should one occur, it could have a disastrous impact on public health. In 2003, an outage in the northeastern regions of the United States and Canada led to a multi-hour blackout that affected more than 50 million people and claimed nearly 100 lives. That outage, however, only lasted a few hours. Should a new outage persist for several days, it could create a nightmare scenario, particularly for elderly populations vulnerable to extreme heat effects.

The dangers of a failed grid extend far beyond air conditioning access, with cascading impacts on water and sanitation, transportation networks, and communication platforms. On July 1, US Energy Secretary Chris Wright declared an Emergency Energy Alert directing the PJM Interconnection, which handles the grid in the Mid-Atlantic, to take measures to reduce the risks of blackouts, including curtailing power to data centers. Ironically, the Trump administration has simultaneously warned of the risks of power outages while paying billions of dollars to wind power producers to not complete planned projects that would help address burgeoning power needs.

Avoiding a World of Runaway Climate Change

As heat waves sadly become more common around the world, local and national governments are increasingly being forced to develop heat management plans to protect citizens, secure electricity and water supplies, support farmers, and safeguard critical infrastructure. Some cities have opened cooling centers to support vulnerable groups, particularly the homeless population, while others have created demand management programs to reduce the risks of power outages. Both are among the preparatory measures governments can take to prevent heat waves from becoming mass casualty events.

However, there are limits to adaptation and resilience measures in a world of runaway climate change. Along the Colorado River in the southwestern United States, higher temperatures and changing rainfall patterns have contributed to major water shortages, affecting the nearly 40 million people who depend on the river for water, irrigation, and power. Lake Powell and Lake Mead, which rely on the Colorado River to provide hydroelectric power for millions, are at some of their lowest levels, threatening their ability to generate electricity and supply water to downstream users.

While conservation measures can help address energy and water demand, without meaningful efforts to restrain greenhouse gas emissions, prolonged droughts and heat waves may become worse and permanent for many Americans and people around the world. With each year now hotter than the last, it is often said in climate circles for each successive year that the previous year was the coolest year any of us will experience in our lives.

Still, the human species is ingenious in its ability to shield itself from climatic conditions. Witness the World Cup this summer, where many of the soccer games are being held in air-conditioned stadiums like those in Dallas and Houston, and where athletes benefit from hydration breaks to cool off. But while these innovations make it tolerable for fans and players alike, humanity cannot simply air condition every setting. Without more intentional action to rein in pollution and a move to cleaner energy, today’s heat waves are simply a harbinger of worse times to come.