This could be the coolest summer of the rest of your life

Summer started with an oppressive heat wave. Get used to it

Summer only just started, but much of the world is already experiencing brutal heat. In the last two weeks, extreme heat waves have struck many parts of the US, Europe and China, threatening lives, increasing the risk of wildfires, and testing the limits of electric grids.

In Minnesota, temperatures soaring above 100 degrees Fahrenheit buckled streets and shattered car windows earlier this week. Thousands of cattle perished in Kansas. Temperatures in France, meanwhile, reached nearly 110°F and set or tied more than 200 monthly heat records across the country.

And that was all before summer technically began — Tuesday was the summer solstice — raising concern among climate scientists that heat waves are arriving earlier as the planet warms. “It’s especially impressive (and unsettling) to see all-time heat records being set in Europe before we even get to the summer solstice,” meteorologist Bob Henson wrote on Twitter over the weekend.

The European heat wave is starting to wane. But extreme heat in the US — the deadliest weather-related phenomenon in the country — is lingering, and moving east from the Great Plains to the southeastern US. An astonishing 70 percent of the US population could see temperatures in the 90s over the next week, including residents of major cities like Atlanta, New Orleans, and Dallas. Tens of millions of American were under a heat advisory Tuesday. Looking farther out, the National Weather Service predicts a hotter than average July, August, and September — offering little hope of relief.

This isn’t normal for June, or for any part of the summer

The world has warmed by 1.1°C (roughly 2°F) since the dawn of the Industrial Revolution. And while that increase might sound modest, it makes extremes much more likely — just check out the graphs below.

Heat waves are becoming more common

Summer is only getting hotter and starting sooner (in a bad way)

What’s especially alarming, according to climate experts, is that these events are happening earlier in the year, when people, cities, and the infrastructure they depend on might not be prepared for extreme heat. “Heat waves that occur earlier in the spring or later in the fall can catch people off-guard and increase exposure to the health risks associated with heat waves,” the EPA writes.(As it gets hotter in a season, people’s bodies can physiologically adapt a bit to cope with heat, but the process takes time.)