By Maddie Stone
In the flurry of actions that President Joe Biden has taken to respond to climate change—rejoining the Paris Agreement, canceling the Keystone XL pipeline, pausing oil and gas leases, directing the government to purchase only zero-emissions vehicles—one move has gotten less attention but may be critical for the future of life on Earth. It concerns a number most people have never heard of.
On January 20, his first day in office, Biden ordered an immediate review and revision of the “social cost of carbon,” a wonky economics metric that represents how much each additional ton of carbon dioxide emitted to the atmosphere costs society. First calculated by the Obama Administration, the number was slashed under former President Donald Trump. That made it easier for his Environmental Protection Agency to justify rolling back major climate regulations, including Obama-era fuel economy standards and the Clean Power Plan.
Experts say that revising the value assigned to the social cost of carbon to once again be in line with science will allow the Biden Administration to craft stricter greenhouse gas regulations across myriad sectors of the economy and ultimately help meet its climate policy goals.
“The executive order is a really exciting step in the right direction,” says Tamma Carleton, an environmental economist at the University of California, Santa Barbara. “It’s exciting that it will be established and updated to reflect best available science.”