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 news agency spoke to more than three dozen scientists about what the destroyed records mean. Most say they fear an acceleration of climate change that is already on the brink of the 1.5 degrees Celsius increase since pre-industrial times, which countries had hoped to keep contained.
“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.
It was especially bad last year.
The climate behaved in strange ways in 2023
Earth’s average temperature has smashed the previous record by just over 0.15 degrees Celsius, a wide margin, according to calculations released Friday by two leading US scientific bodies, the British Meteorological Agency and a private group founded by a climate skeptic.
Several scientists who made the calculations said the climate was behaving strange ways in 2023. They wonder whether man-made climate change and a natural El Nino were amplified by a bizarre blip or whether “something more systematic is going on,” as NASA climate scientist Gavin Schmidt put 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 the waters of the Pacific Ocean, which influences global weather patterns, is expected to disappear. If ocean temperatures, including deep water, continue to rise records well into the summer, like 2023, that would be an ominous indication, they say.
Nearly every scientist who responded to AP’s questions blamed greenhouse gas emissions 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 say.
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 era estimated.
Temperatures tend to be highest above normal in late winter and spring, they say. But the highest heat of 2023 occurred June and remained at record levels for months.
The heat of the deep oceans, which plays a major role in global temperatures, behaved in a similar way, Burgess says.
Is global warming accelerating faster than predicted?
Former NASA climate scientist James Hansen, often considered the godfather of global warming science, theorized that last year pre workout 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 over the past decade than it has been over the past decade — which meets the mathematical definition of acceleration,” said climate scientist Daniel Swain of UCLA. “However, this is also largely in line with the predictions” that warming would occur accelerate at some point, especially when particulate pollution in the air decreases.
The US National Oceanic and Atmospheric Administration (NOAA) has calculated that the Earth had an average temperature of 15.08 degrees Celsius in 2023. That is 0.15 degrees Celsius warmer than the previous record from 2016 and 1.35 degrees Celsius warmer than pre-industrial temperatures.
“It’s almost like we jumped down the stairs [of normal global warming temperature increases] to a slightly warmer regime,” said Russ Vose, global monitoring lead for NOAA’s National Centers for Environmental Information. He says he sees an acceleration of warming.
NASA and the United Kingdom Meteorological Office had warming slightly higher since the mid-19th century at 1.39C and 1.46C 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 that 2023 would be 1.45 degrees Celsius warmer than pre-industrial temperatures.
Is a warming limit of 1.5 degrees Celsius still feasible?
Many climate scientists saw little hope of stopping global warming Target of 1.5 degrees 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,” said Jennifer Francis, scientist at the Woodwell Climate Research Center. “It is technically possible, but politically speaking impossible.”
“The slow pace of climate action and the persistent misinformation that underpins it 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” says Katharine Hayhoe, chief scientist at The Nature Conservancy.
Both NASA and NOAA say that the last ten years, from 2014 to 2023, have been the ten years hottest years they measured. 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, says the big concern is not that a record was broken last year, but that they are broken so often.
“For me, the speed of constant change is what is most alarming,” says Cerveny.
Climate scientist Natalie Mahowald of Cornell University says: “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.”