The Biden administration announced it will use Obama-era calculations of the “social cost” of three greenhouse gas pollutants while an interagency working group calculates a more complete estimate, the White House announced Friday. Often described as “the most important number you’ve never heard of,” the “social cost” of greenhouse gasses estimates the harms to society caused by each ton of carbon dioxide, methane, and nitrous oxide emitted into the atmosphere. Those estimates are used across government in calculating the costs and benefits of proposed actions. Though the administration did not specify the exact costs, multiple outlets report the interim estimate of the social cost of carbon will be approximately $51 per ton.