Carbon should cost 3.6 times more than US price, study says

Each ton of carbon dioxide that exits a smokestack or tailpipe is doing far more damage than what governments take into account, researchers conclude in a scientific paper published Thursday.

Major hurricanes pack more rain, while extremes of wildfire, drought and downpours are all happening more often and with more intensity due to climate change, causing loss of communities, homes and lives all over the world. But what is the actual cost in dollar terms of the carbon emissions driving climactic change?

That's what researchers from a variety of fields — science, economics, medicine — are trying to figure out through a metric called the social cost of carbon, a price that represents the total climate damage caused to society through carbon emissions. It's been used in the past to justify tougher limits on carbon emissions and more spending on climate solutions, like transitioning to renewable energy and natural flood protection.

Currently, the United States government uses a price of $51 per ton of carbon dioxide emitted, but the researchers wrote in the journal Nature that the price should be $185 per ton — 3.6 times higher than the current U.S. standard.

“Our results suggest that we are vastly underestimating the harm from each additional ton of carbon dioxide in the atmosphere,” said Kevin Rennert, a study author and director of the federal climate policy initiative at Resources for the Future, an environmental nonprofit based in Washington, D.C. “And the implication is that the benefits of government policies and other actions that reduce global warming pollution are greater than has been estimated."

Rennert and colleagues created an updated model to measure the societal cost of emitting carbon that includes several measures excluded in previous research. They...