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Predicting the future is always a difficult and sometimes futile endeavor, but scientists have been surprisingly good at predicting how hot it will be next year. For decades, their models have been pretty consistent with global temperatures. Then 2023 arrived.
Earlier this year, climate scientists from four organisations – Berkeley Earth, NASA, the UK Met Office and Carbon Brief – predicted that 2023 would be slightly hotter than the previous year, with the consensus being 1.2 degrees It was predicted that temperatures would rise by 2.2 degrees above pre-industrial levels, but this is much higher than expected. The hottest year on recordIt is estimated that 1.5℃ (2.7 degrees Fahrenheit). “We were way off, and we don’t know why,” said Zeke Hausfather, one of the Berkeley Earth scientists who worked on the prediction.
The first signs that something was wrong came in March 2023. Global ocean temperatures reach record high It was the hottest June in modern history. And the heat hit land too. It was the hottest June on record, followed by the hottest July, and the hottest month of every month since. On Wednesday, the European Union’s Copernicus Climate Change Service confirmed that last month was the hottest May on record, marking a record-breaking year of global temperatures, with an average rise of 1.63 degrees Celsius compared to pre-industrial times. The report said: World Meteorological Organization’s latest forecast One of the next five years is likely to surpass 2023 as the warmest year on record.
The two reports came as a heat wave raged across the western U.S., putting 29 million Americans under heat watches or warnings Wednesday into the weekend. “If we choose to continue releasing greenhouse gases into the atmosphere, 2023/2024 will soon be a cool year,” Samantha Burgess, director of the Copernicus Climate Change Service, said in a statement.
Much of the warming over the past year has been within the range that scientists have long predicted is due to the overuse of fossil fuels. Temperatures rose even higher last summer as a recurring weather pattern known as El Niño took hold. But scientists say these two factors alone cannot explain the recent spike in global temperatures, especially in the second half of 2023. Was this extra warming a blip that could be brushed aside and chalked off to natural variability or a coincidence, or was it a sign that climate change was starting to deviate from a predictable trajectory?
“This isn’t just some obscure weird thing that nobody cares about,” says Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies in New York. “It’s a really important problem, and how this is solved will have implications for the future.” Schmidt and other scientists are considering a variety of theories that could explain the rising temperatures, from a decrease in global aerosol pollution to undersea volcanic eruptions. “Any number of possibilities are possible,” he says.
Here’s what scientists know so far: Climate change is causing the Earth to 1.3 degrees Temperatures have risen since pre-industrial times. However, the latest data shows that temperatures have risen by 1.6°C over the past 12 months. Of that, around 0.1°C to 0.2°C is due to the warming of the Pacific Ocean caused by the El Niño phenomenon. 0.2℃ I can’t explain it.
The scientists A solid explanation Perhaps for just 0.1°C of extra heat, a side effect of global efforts to reduce pollution. Starting in January 2020, the International Maritime Organization Forced reduction Sulfur oxide emissions from marine fuels. These airborne particles Harmful It’s harmful to human lungs, causes acid rain and stunts plant growth, but it also increases cloud cover and reflects heat back into space. The paper was published in Nature magazine last week. It turns out that if some of these aerosol particles suddenly disappear, the Earth begins to absorb more heat.
The search for other pieces of the puzzle continues. The 2022 volcanic eruption The warmth increased massive Water vapor traps heat Released into the atmosphere. Changes in weather patterns usually Crossing the AtlanticMore sunlight is now heating the oceans, which could be the start of increased solar activity. Faster than expectedOr China is trapping radiation in the atmosphere. Cleaning up air pollution faster than expectedAnd there are even fewer aerosols to reflect heat away from the Earth.
Read next: The Pollution Paradox: How Removing Smog Increases Ocean Warming
Even more ominously, some scientists believe that the Earth are more sensitive to climate change than previously thought“The climate system is an angry beast, and we’re poking it with a stick,” geochemist Wallace Blocker, who died in 2019, used to say. Daniel Swain, a climate scientist at the University of California, Los Angeles, thinks it might be time to revise that metaphor. “We’re getting closer to the beast, and it’s happening more frequently and on a larger scale than it’s ever been,” he says. “So at some point, we might see some surprises.”
Swain says solar activity and other suspects are too far-fetched to explain the “wild card” that caused so much warming in 2023. He doubts the mystery will even be solved. Schmidt, meanwhile, is hopeful that scientists will figure out the X-factor by the end of the year.
While temperatures this year continue to break records, scientists haven’t been as surprised as they were in 2023. The heat in recent months has been more in line with what scientists had predicted. Expected from El NiñoAnd El Niño’s cooling twin, La Niña, is expected to dominate this summer. If temperatures don’t drop as expected a few months from now, “I think it’s a sign that we all know something is going on that we didn’t expect and that we don’t have a good explanation for,” Hausfather said.
This article was originally published on Grist in In 2023, Mystery X-Factor became the most obsessive fanatic in human history.Grist is a nonprofit, independent media organization dedicated to telling stories about climate solutions and a just future. For more information, Grist
