The latest calculations from several scientific agencies showing that Earth shattered global heat records last year may seem frightening. But scientists fear what’s behind these numbers could be even worse.
The Associated Press asked more than three dozen scientists in interviews and emails what the destroyed records mean. Most said they fear an acceleration of climate change that is already bordering on the 1.5 degrees Celsius (2.7 Fahrenheit) increase since the pre-industrial era that countries had hoped to keep within.
“The heat of the past calendar year was a dramatic message from Mother Nature,” says climate scientist Katharine Jacobs of the University of Arizona. Scientists say warming air and water are making deadly and costly heat waves, floods, droughts, storms and wildfires more intense and likely.
Last year it was a doozy.
Earth’s average temperature broke the previous record by just over a quarter of a degree (0.15 degrees Celsius), a wide margin, according to calculations Friday by two top U.S. science agencies, the British Meteorological Agency and a private group set up by a climate organization. skeptic.
Several scientists who made the calculations said the climate in 2023 was behaving in strange ways. They wonder if man-made climate change and a natural El Nino were amplified by a strange blip or if “something more systematic is going on,” as NASA says. scientist Gavin Schmidt said it – including a much-discussed acceleration of warming.
A partial answer may not come until late spring or early summer. That’s when a strong El Nino — the cyclical warming of Pacific Ocean waters that affects global weather patterns — is expected to dissipate. If ocean temperatures, including deep water, continue to set records well into summer, as they will in 2023, it would be an ominous indication, they say.
Nearly every scientist who responded to AP’s questions blamed greenhouse gases from the burning of fossil fuels as the overwhelming biggest reason why the world is experiencing temperatures unlike anything human civilization has ever seen before. El Nino, bordering on “very strong,” is the second biggest factor, with other conditions lagging far behind, they said.
The problem with 2023, according to NASA’s Schmidt, is: “It was a very strange year… The more you dig into it, the less clear it seems.”
Part of that is the timing for when the great heat wave of 2023 began, according to Schmidt and Samantha Burgess, deputy director of Europe’s Copernicus Climate Service, who earlier this week pegged warming at 1.48 degrees Celsius above pre-industrial time set.
Temperatures tend to be highest above normal in late winter and spring, they said. But the highest heat of 2023 started around June and remained at record levels for months.
Deep ocean heat, a major player in global temperatures, behaved in a similar way, Burgess said.
Former NASA climate scientist James Hansen, often considered the godfather of global warming science, theorized last year that warming was accelerating. While many of the scientists contacted by AP said they suspect this is happening, others were adamant that the evidence so far only supports a steady and long-predicted increase.
“There is some evidence that warming has been slightly faster in the last decade than in the previous decade – which meets the mathematical definition of acceleration,” said climate scientist Daniel Swain of UCLA. However, “this is also largely consistent with predictions” that warming will accelerate at some point, especially as particulate pollution in the air decreases.
The US National Oceanic and Atmospheric Administration has calculated that the Earth had an average temperature of 59.12 degrees (15.08 degrees Celsius) in 2023. That is 0.27 degrees (0.15 degrees Celsius) warmer than the previous record from 2016 and 2.43 degrees (1.35 degrees Celsius) warmer than pre-industrial temperatures.
“It’s almost as if we’ve jumped down the stairs (from the normal temperature increases of global warming) to a slightly warmer regime,” said Russ Vose, global monitoring lead for NOAA’s National Centers for Environmental Information. He said he sees an acceleration of warming.
NASA and the United Kingdom Meteorological Office had warming slightly higher since the mid-19th century at 2.5 degrees (1.39 degrees Celsius) and 2.63 degrees (1.46 degrees Celsius), respectively. The data goes back to 1850.
The World Meteorological Organization, which combined the measurements announced Friday with Japanese and European calculations released earlier this month, estimated 2023 to be 1.45 degrees Celsius (2.61 degrees Fahrenheit) warmer than pre-industrial temperatures.
Many climate scientists saw little hope of stopping warming at the 1.5 degree target called for in the 2015 Paris agreement, which aimed to avert the worst effects of climate change.
“I don’t think it’s realistic that we can limit warming (averaged over several years) to 1.5 degrees Celsius,” Woodwell Climate Research Center scientist Jennifer Francis wrote in an email. “It is technically possible, but politically impossible.”
“The slow pace of climate action and the persistent disinformation it catalyzes has never been about a lack of science or even a lack of solutions: it has always been and remains about a lack of political will,” said Katharine Hayhoe, chief scientist at The Nature Conservancy.
Both NASA and NOAA said the past decade, from 2014 to 2023, were the 10 warmest years they have recorded. It is the third time in the past eight years that a world heat record has been set. Randall Cerveny, an Arizona State University scientist who helps coordinate record-keeping for the WMO, said the big concern is not that a record was broken last year, but that they are broken so often.
“It is the rate of constant change that is most alarming to me,” Cerveny said.
Climate scientist Natalie Mahowald of Cornell University said: “This is just a taste of what we can expect in the future, especially if we fail to reduce CO2 emissions quickly enough.”
That’s why so many scientists contacted by The Associated Press are concerned.
“I’ve been concerned since the early 1990s,” says climate scientist Kim Cobb of Brown University. “I’m more worried than ever. My concerns grow every year that global emissions are moving in the wrong direction.”
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