The past three days may be the warmest in Earth’s modern history, scientists said Thursday, as a surprising surge of heat around the world continues to break temperature records from North America to Antarctica.
The spike comes as forecasters warn that Earth could enter a multi-year period of exceptional warming 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 Niño, a cyclical weather pattern.
And in the North Atlantic, the ocean is not as warm. Surface temperature in May It was 2.9 degrees Fahrenheit or 1.6 degrees Celsius warmer It beat previous records by an unusually large margin over this year’s norm.
The sharp increase in temperature has made even scientists who monitor climate change uneasy.
“It’s hard to wrap your head around what’s been observed,” said Brian McNoldy, a senior research scientist at the University of Miami. “It just doesn’t seem real.”
On Tuesday, the global average temperature rose to 62.6 degrees Fahrenheit or 17 Celsius. It was the hottest day Earth has experienced since at least 1940According to an analysis by the European Union’s Copernicus Climate Change Service, when the records began, and possibly even earlier.
Because it was average, some parts of the world felt that extra heat very strongly. For example, in the southern United States and northern Mexico, where the heat index has reached triple digits, climate change has made the current heat wave 5 degrees Fahrenheit warmer, according to scientists at the Lawrence Berkeley National Laboratory. In California.
The planet’s overall warming is “within the range of what scientists have predicted,” as humans continue to pump large amounts of heat-trapping greenhouse gases into the atmosphere, said Zke Hausfather, a Berkeley Earth and paid climate scientist. Company Stripe.
Overall, the Earth has warmed about 2 degrees Fahrenheit since the 19th century, and will continue to grow warmer until humans stop all emissions of fossil fuels and stop deforestation.
But other factors layered on top of human-caused warming may have helped accelerate temperatures 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 by shifting heat in and out of the deep ocean layers. Global surface temperatures are cooler during La Nina years and warmer during El Niño years.
“A big reason so many records have been broken is that we’re transitioning from an unusually long three-year La Niña, suppressing temperatures, to a strong El Niño,” Dr Hausfather said.
This means more heat is coming. The current El Niño has just begun and many researchers don’t expect it to peak until December or January, the months after which see another surge in global temperatures. Scientists have said that next year will be hotter than this year.
Other dynamics may be at work. The North Atlantic has seen much warmer temperatures since early March, before El Niño conditions set in. One factor may be a subtropical high pressure system called the Azores High, which has weakened the winds blowing over the ocean and limited the amount of dust blowing from the Sahara, which normally helps cool the ocean.
Those weather patterns could change in the coming weeks, said Dr. McNoldy of the University of Miami. “But even then, we’ll go from very record-breaking temperatures to very record-breaking temperatures,” he said.
Other researchers have recommended Recent efforts to remove sulfur pollution from ships around the world may increase temperatures slightly, as sulfur dioxide reflects sunlight and partially cools the planet. However, that precise impact is still debated.
“There appears to be an extraordinary convergence of warming factors right now,” said Princeton climate scientist Gabriel Vecchi. “But all of this is happening in a world where we’ve been increasing greenhouse gases for the last 150 years, and it’s really rolling the dice and we’re going to be pushed into record territory.”