Summer 2024 is already the hottest on record

The Northern Hemisphere just experienced the hottest summer on record since at least 1940, even topping last year’s record-breaking season, according to the European Union’s Copernicus Climate Change Service.

Scorching temperatures so far this year also put 2024 on track to be the hottest year since recordkeeping began in 1850, potentially unseating 2023 for the top spot. Temperatures have risen steadily since greenhouse gas emissions from burning fossil fuels soared with the Industrial Revolution, showing a clear trend in the data.

“The temperature-related extreme events witnessed this summer will only become more intense, with more devastating consequences for people and the planet unless we take urgent action to reduce greenhouse gas emissions,” Samantha Burgess, deputy director of the Copernicus Climate Change Service, said in a statement today.

Hotter summers can trigger all sorts of negative consequences. Olympic athletes raised concerns about the heat impacting their performance and posing health risks in Paris this year, with many teams opting to ship in their own air conditioning to the Olympic Village. The Games aside, spikes in electricity demand for air conditioning during heatwaves can raise electricity bills, stress out the power grid, and cause more blackouts during the summer.

And when people can’t cool down, heat exhaustion can lead to heat stroke and even death. Heat-related deaths have climbed in the US since 2016, peaking with 2,325 documented last year. This is a problem felt across the world. This June, at least 1,300 people died during the annual pilgrimage to Mecca as temperatures reached as high as 49 degrees Celsius (120 degrees Fahrenheit).

The dataset Copernicus uses for its analysis only goes back to 1940. But other recently published research using markers in ancient tree rings found that summer 2023 was likely the hottest for the Northern Hemisphere in at least 2,000 years.

Even compared to more recent years, this summer was hot. Global average temperatures between June and August were 0.69 degrees Celsius above the average from 1991 to 2020. Every fraction of a degree matters since climate change can lead to much more stark impacts at the local level.

The goal of the Paris climate agreement is to keep global average temperatures from rising more than 1.5 degrees Celsius higher than they were before the Industrial Revolution. Doing so would have tremendous health benefits, preventing between 110 and 2,720 heat-related deaths each year across 15 US cities, researchers estimate.