Climate models omit a major source of warming, according to a newsletter article from MIT Technology Review. The article says that climate feedback loops, which occur when warming triggers further warming, are not fully accounted for in current climate models or in emissions-reduction goals.
The article cites a September study in Environmental Research Letters. That study, which synthesized earlier research, found that carbon dioxide and methane released from thawing permafrost, intensifying wildfires, hotter lakes and reservoirs, and wetter, warmer wetlands could raise global average temperatures by 0.2 °C to 0.4 °C this century. Modelers already expect 2.6 °C of warming above preindustrial levels through 2100.
The article says none of the models informing major UN climate reports account for all of these feedback effects, and many include none. A March analysis in One Earth, according to the article, found that three regional feedback sources could shorten by as much as 25% the time before the planet consistently breaches the 1.5 °C and 2 °C thresholds.
Sam Abernethy, lead author of the One Earth paper and a climate scientist at Spark Climate Solutions, a San Francisco-based nonprofit research group, says the climate models and UN reports need updating. He says nations must also step up emissions reductions. The article reports that more than 20 international teams are running a shared set of analyses through Spark's Warming-Induced Greenhouse Gas Emissions Model Intercomparison Project. Researchers hope the UN will include the results in its next major climate assessment, due in 2029.
The article also describes early research into countermeasures, including fire prevention and rapid fire suppression near permafrost at the Woodwell Climate Research Center, and lab work on adding sulfate, iron, or other compounds to wetlands, backed by the Environmental Defense Fund's Climate Innovation Initiative. It says researchers are in the earliest stages of assessing how much these efforts could reduce emissions.