Last year was the hottest on record for the Earth’s land and oceans, capping a clear, decades-long warming trend that will continue producing more frequent and costly disasters, the U.S. government’s chief scientists warned Friday.

Not only was 2023 the warmest year since pre-industrial times, it was significantly warmer than the last record that was set in 2016, according to a joint presentation by the National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA).

“The bigger point here is all of this is consistent with increasing concentrations of heat-trapping gases,” said Russell Vose of NOAA’s National Centers for Environmental Information. He said atmospheric concentrations of carbon dioxide — the greenhouse gas responsible for most of the global warming trend — are about 50% higher than pre-industrial levels, the highest they’ve been in 2 million years. Methane is also up about 150%.

“It’s been a long time since they’ve been this high,” Vose said.

Global temperatures last year were between 2.12 and 2.16 degrees Fahrenheit above the average observed between 1901 and 2000, according to the agencies, which conducted separate but similar analyses. Both ranked 2023 as the warmest on record since at least the mid-1800′s. Their analyses were based on data collected from over two dozen satellites, as well as land, air and water measurements, and mirror findings from scientific agencies around the world showing 2023 was a record-breaking year for heat. NOAA predicts 2024 has a one-in-three chance of beating 2023′s record as the hottest year.

“We’ve been observing the Earth for decades, so we can see the state today and how it’s changing over time,” said NASA chief scientist Kate Calvin. “One of the things we’re observing is climate change, which is impacting people and communities around the world.”

Locally, 2023 was the second-hottest for the city of Atlanta and the sixth hottest for the state.

The increase in global temperatures is also making extreme weather events more frequent and more damaging. The U.S. saw 28 separate billion-dollar weather and climate disasters in 2023, smashing the previous record of 22 set in 2020, according to NOAA.

Environmental groups and others reacted to the analyses by calling for urgent action to transition away from burning fossil fuels, the main driver of climate change.

“We’ve crossed a critical threshold,” Manish Bapna, president of the Natural Resources Defense Council, said in a statement. “We must respond with decisive action to speed the shift from fossil fuels, adapt to the consequences baked into the system and mobilize the resources to help the world’s most vulnerable people cope with cascading catastrophes they didn’t cause.”


A note of disclosure

This coverage is supported by a partnership with Green South Foundation and Journalism Funding Partners. You can learn more and support our climate reporting by donating at ajc.com/donate/climate/