By Chelsea Harvey
“Tipping elements” in the rapidly warming Arctic may add trillions of dollars to the long-term costs of climate change, a new study suggests.
As temperatures rise, thawing permafrost may release large amounts of carbon dioxide and methane into the atmosphere, causing even more warming. At the same time, the disappearance of snow and ice cover — bright, reflective surfaces that help to beam sunlight away from the planet — will cause the Earth to absorb even more heat.
The result is to worsen the progression of climate change even further.
The problem is that these processes haven’t been adequately accounted for, if at all, in many of the models scientists use to make projections about the future. That means previous calculations may be underestimating the damages associated with long-term warming.
The new study, published yesterday in the journal Nature Communications, suggests that the extra costs could amount to nearly $67 trillion over the next few hundred years under a trajectory consistent with the climate action that nations have promised so far under the Paris Agreement — that’s on top of the hundreds of trillions of dollars already predicted in baseline costs from climate change. Researchers estimate that the world would likely experience about 3 degrees Celsius of total warming under such a scenario.
Limiting warming to 1.5 or 2 C, the ultimate goals of the Paris Agreement, would still carry significant extra costs. But the savings could be substantial compared with more severe scenarios. The extra costs in a 2 C world would amount to nearly $34 trillion by 2300 and would come to nearly $25 trillion under 1.5 C of warming.
It’s a much longer-term vision than some other estimates present — many climate change projections tend to focus on 2100 as a benchmark. But the “true impact” of certain climate consequences, like the slow thawing of permafrost, can take centuries to manifest, according to study co-author Kevin Schaefer of the National Snow and Ice Data Center.
“True, we don’t know exactly what society and the economy will look like 300 years in the future,” he told E&E News. “But this is still a useful tool to get an idea of what that will look like in today’s dollars.”
According to environmental economist Amir Jina of the University of Chicago, who wasn’t involved with the research, the exact dollar amounts presented in the study may be less important than the overall indication that tipping elements are an important, and underrepresented, consideration when it comes to climate damage.
The type of model used to conduct the new research is very useful when “thinking about how much certain parameters matter when you’re thinking about climate change and the costs of climate change,” he said.
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