The past three days were likely the hottest in Earth’s modern history, scientists said, as a blistering heatwave across the planet continued to shatter temperature records from North America to Antarctica.
The spike comes as forecasters warn that the Earth is entering a multi-year period of exceptional warmth driven by two main factors: humans continue to burn oil, gas and coal along with the return of El Niño, a cyclical weather pattern, after three years.
Already the increase was drastic. The planet only experienced its hottest June ever recordedEuropean researchers said, with deadly heat waves in Texas, Mexico and India. In the North Atlantic, ocean temperatures were 2.9 degrees Fahrenheit warmer in May than they usually are at that time of year. Around Antarctica, sea ice levels have plunged to record lows.
And the heat shows no signs of abating. On Monday, global average temperatures reached 62.6 degrees Fahrenheit, or 17 degrees Celsius, the hottest day on record, according to the Climate Reanalyzer from University of Mainewhich combines satellite data, observations and computer modeling to provide a real-time update of climate conditions.
But that record was shattered the next day. On Tuesday, global average temperatures rose to a new high of 62.9 degrees Fahrenheit.
A separate analysis by the European Union’s Copernicus Climate Change Service confirmed that Tuesday was the hottest day the Earth has experienced since at least 1940when records began, and very likely before that.
The planet’s overall warming is “well within the realm of what scientists projected would happen” because humans have continued to pump hot greenhouse gases into the atmosphere, said Zeke Hausfather, a climate scientist at Berkeley Earth and the payments firm Stripe.
But, he added, there may be other factors layered on top of human-caused warming that have helped raise temperatures so dramatically in recent months. For example, a cyclical phenomenon in the Pacific Ocean known as the El Niño-Southern Oscillation causes year-to-year fluctuations in shifting heat in and out of deeper ocean layers. Global surface temperatures tend to be a little cooler during La Niña years and a little warmer during El Niño years.
“A big reason we’re seeing so many records being broken is that we’re transitioning out of an unusually long three-year La Niña, which depressed temperatures a bit, and into a strong El Niño,” Dr. Hausfather said.
Other dynamics may also be at play. In January 2022, a volcanic eruption beneath the Pacific archipelago of Tonga blasted a huge amount of evaporated seawater into the atmosphere that could trap additional heat. Some scientists also suggested that efforts to clean up sulfur pollution from ships and coal plants around the world might raise temperatures slightly, as sulfur dioxide in the atmosphere tends to have a slight cooling effect. But scientists have yet to definitively unravel its role in the current heat wave.