Climate Change Made This Week’s Heatwave “Virtually Impossible,” Researchers Say

Heat across the U.S. this week would have been “virtually impossible” without the climate crisis, according to a study by the World Weather Attribution (WWA) consortium, a group of international climate researchers. The analysis, released as a heat dome blankets the central and eastern U.S., links the extreme temperatures to a 1.4C (2.5F) rise in global temperatures.

What Caused the Heat?

A high-pressure system, or heat dome, has trapped hot, humid air over much of the central and eastern U.S., as well as southern parts of Canada. Researchers at Imperial College London, including Theodore Keeping, an extreme weather and wildfire researcher, found that such heatwaves—estimated to occur one time in every 200 years—would not have been expected to occur even once in many thousands of years without human-driven climate change. “The climate the country has today is fundamentally different to the one it had when the founding fathers signed the Declaration of Independence,” Keeping said in a press release.

How Are Events Affected?

The extreme heat has disrupted major events, including the 250th-anniversary celebrations in Washington, D.C. The Great American State Fair postponed events at 1pm local time on Friday until 5pm, with people there being ushered to the exits. World Cup matches are also at risk: France’s game against Paraguay in Philadelphia and Cape Verde’s match against Argentina in Miami are expected to take place in conditions that a global players’ union has previously said should trigger the delay or postponement of games.

What Are the Health Risks?

In Muhlenberg Township, Pennsylvania, more than 100 people at a Union Pacific Big Boy whistle stop event required heat-related medical treatment, officials reported. The incident, treated as a mass casualty event, involved ambulances, cooling buses, and tents. Friederike Otto, professor of climate science at the Centre for Environmental Policy at Imperial College London, warned that such scenarios highlight the urgency of reducing greenhouse gas emissions. “When a historic Fourth of July celebration is disrupted, and World Cup matches are played in conditions that are unsafe for players and fans, it shouldn’t take another scientific study to wake people up,” she said.

Why Does This Matter?

The WWA study underscores the need for immediate action, with researchers emphasizing that the climate crisis is already impacting the things we enjoy in our everyday lives, and it will continue to get worse the longer the world drags out the transition to net zero emissions.

World Weather Attribution | Intergovernmental Panel on Climate Change