Global warming slowdown projected, with caveats

• But scientists say it shouldn't trigger complacency.

What they're saying: "Although bad actors could misinterpret these results as yet another reason to continue to delay more climate action, in fact they emphasize even more strongly the efficacy of the actions taken to date and the urgency of more," Katharine Hayhoe, a climate researcher who is chief scientist at The Nature Conservancy, told Axios.

Zoom in: The research, published as a viewpoint in the journal Environmental Research Letters, makes a simple — yet perhaps underappreciated — point.

• While the pace and scale of climate action are currently unlikely to be successful at limiting global warming to the Paris Agreement targets, national policies are becoming significant enough to slow the rate of increase in global average temperatures and some of the worst associated impacts.
• In the analysis, two researchers from the Carnegie Institution for Science Department of Global Ecology at Stanford University found that the rate of warming is anticipated to be around 0.21°C (0.37°F) per decade in 2025.
• This would decline to 0.15°C (0.27°F) per decade around the year 2050.

Between the lines: The future warming rates would depend on whether countries meet their climate change commitments and if more stringent emissions cuts are made.

• "The main purpose of the paper is to show that under current emissions reduction policies globally, despite regional disparities, it is likely that total annual carbon emissions are going to decrease compared to previous years," study lead author Lei Duan told Axios via email. "And this would lead to a slowdown of the warming rate due to anthropogenic activities."
• Lei cautioned this would not necessarily result in less warming overall, and it does not consider country commitments to the UN climate summit policies, but rather national policies only.

Threat level: In addition, the researchers caution that climate damage could prove non-linear, meaning that even a decrease in the warming rate would trigger major climate damage.

• Other complications may occur, such as faster-than-expected cuts in emissions of tiny particles known as aerosols, which are part of air pollution but also act to offset some of the warming from greenhouse gas emissions.

What they're saying: "If anything, these results should increase our sense of collective efficacy — which is sorely needed," Hayhoe, who was not involved in the new research, said.

• Citing a 2018 UN IPCC report that emphasized the climate effects of each small increment of avoided warming, she stated: "Now we know it matters even more quickly than we did back then."

Yes, but: The study doesn't address the reasons for the unusual spike in global average surface temperatures in 2023 into the first half of this year, NASA climate scientist Gavin Schmidt, who also wasn't involved in the new paper, told Axios.

• "I'm unclear as to why this is interesting," Schmidt said. "If we reduce emissions it won't warm as fast, and if we get to net zero, it will basically stop," he said, emphasizing that this was already known.
• He said the study ignores the possible factors that could account for the rapid warming last year into this year, which has unnerved scientists and led some to predict an acceleration in the rate of warming in future years.