Heat records are broken around the globe as earth warms, fast

NEW YORK – The past three days were quite likely the hottest in earth’s modern history, scientists said on Thursday, as an astonishing surge of heat across the globe continued to shatter temperature records from North America to Antarctica.

The spike comes as forecasters warn that earth could be entering a multi-year period of exceptional warmth driven by two main factors: continued emissions of heat-trapping gases, mainly caused by humans burning oil, gas and coal; and the return of El Nino, a cyclical weather pattern.

Already, the surge has been striking.

The planet just experienced its warmest June ever recorded,

researchers said, with deadly heatwaves scorching Texas, Mexico and India. Off the coasts of Antarctica, sea ice levels in 2023 have plummeted to record lows.

In the North Atlantic, the ocean has been off-the-charts hot. Surface temperatures in May were 1.6 deg C warmer than typical for this time of year, breaking previous records by an unusually large margin.

The sharp jump in temperatures has unsettled even those scientists who have been tracking climate change.

“It’s so far out of line of what has been observed that it’s hard to wrap your head around,” said Mr Brian McNoldy, a senior research associate at the University of Miami. “It doesn’t seem real.”

On Tuesday, global average temperatures climbed to 17 deg C, making it the hottest day that earth has experienced since at least 1940, when records began, and very likely before that, according to an analysis by the European Union’s Copernicus Climate Change Service.

Since that was an average, parts of the globe felt that extra heat more forcefully. For instance, in the southern United States and northern Mexico, where the heat index has reached triple digits, climate change has made the ongoing heat wave about 2.8 deg C hotter than it would have been otherwise, according to scientists at the Lawrence Berkeley National Laboratory in California.

The overall warming of the planet is “well within the realm of what scientists had projected would happen” as humans continue to pump vast amounts of heat-trapping greenhouse gases into the atmosphere, said Dr Zeke Hausfather, a climate scientist at Berkeley Earth and payments company Stripe.

On the whole, earth has warmed by roughly 1 deg C since the 19th century and will continue to grow hotter until humans essentially halt all emissions from fossil fuels and stop deforestation.

But other factors layered on top of human-caused warming may have helped temperatures accelerate dramatically in recent months.

For instance, a cyclical phenomenon in the Pacific Ocean known as the El Nino-Southern Oscillation causes year-to-year fluctuations by shifting heat in and out of deeper ocean layers. Global surface temperatures tend to be cooler during La Nina years and hotter during El Nino years.

“A big reason we’re seeing so many records shattered is that we’re transitioning out of an unusually long three-year La Nina, which suppressed temperatures, and into a strong El Nino,” Dr Hausfather said.

This probably portends even more heat is coming. The current El Nino is just getting under way, and many researchers do not expect it to peak until December or January, with global temperatures seeing another surge in the months thereafter. This means that 2024 could be even hotter than this year, scientists said.

Other dynamics may be at work too. The North Atlantic has seen record heat since early March, before El Nino conditions began. One factor may be a subtropical high pressure system known as the Azores High that has weakened the winds blowing over the ocean and limited the amount of dust blowing from the Sahara, which normally helps cool the ocean.

These weather patterns could change in the weeks ahead, said Mr McNoldy. “But even then, we’d probably be going from insanely record-breaking temperatures down to just extremely record-breaking,” he said.

The soaring heat has led some meteorologists to increase their warnings about 2023’s hurricane season. On Thursday, forecasters at Colorado State University said they now expect an above-average Atlantic hurricane season, with about 18 tropical cyclones, a reversal from earlier forecasts of a quieter-than-usual year.

Hurricanes in the Atlantic are often suppressed during El Nino years, but that may be not be true this year because of the unusually warm ocean waters, which can fuel storms.

Other researchers have suggested that recent efforts to clean up sulphur pollution from ships around the world may be pushing up temperatures slightly, since sulphur dioxide tends to reflect sunlight and cool the planet somewhat. This precise impact is still being debated, however.

“There does seem to be this unusual convergence of warming factors right now,” said Professor Gabriel Vecchi, a climate scientist at Princeton. “But this is all happening in a world where we’ve been increasing greenhouse gases for the past 150 years, and that really loads the dice and makes it much more likely that we’re going to get pushed into record-breaking territory.” NYTIMES