US Heatwave Threatens 250th Anniversary Events and World Cup

A powerful heatwave is sweeping across much of the United States this week, threatening Fourth of July celebrations and World Cup soccer matches. Scientists say the extreme heat and humidity would have been 'virtually impossible' without climate change. The dangerous conditions are expected to last through the holiday weekend, putting millions of people at risk.

Researchers from a group called World Weather Attribution studied the heatwave and released their findings this week. They found that burning fossil fuels has warmed the planet, making deadly heat events much more likely. Even with climate change, a heatwave this severe only happens about once every 200 years. Without the roughly 1.4 degrees Celsius of warming humans have caused, such an event might not happen even once in thousands of years.

A 'heat dome' — a system of high pressure that traps hot air — is sitting over the central and eastern United States. It is also affecting parts of southern Canada. The combination of high temperatures and heavy humidity makes it feel even hotter and more dangerous than the thermometer shows.

Washington, D.C., is expected to see some of the hottest temperatures. Thousands of people are planning to gather there to celebrate the 250th anniversary of the United States. Researcher Theodore Keeping of Imperial College London noted that the climate in America today is very different from what it was when the Founding Fathers signed the Declaration of Independence in 1776.

World Cup soccer matches this weekend could also be in danger. France is set to play Paraguay in Philadelphia on Saturday, where extreme heat is expected. A global players' union has said that conditions like these should trigger delays or postponements of games. A match between Cape Verde and Argentina in Miami on Friday is also expected to be played in potentially harmful heat and humidity.

Climate scientist Friederike Otto, also from Imperial College London, said the world must quickly reduce greenhouse gas pollution. She pointed out that when a historic national celebration is disrupted and World Cup matches are unsafe, it is a clear sign that action is needed. 'Climate change is here; it's already impacting the things we enjoy in our everyday lives, and it will continue to get worse the longer we drag out the inevitable transition to net zero emissions,' she said.