One of President Donald Trump’s most damaging strikes at the foundation of U.S. climate policy is buried deep in a sweeping Inauguration Day executive order focused on “Unleashing American Energy.” Half way through the lengthy document is a directive that would obliterate an obscure but critically important calculation the government uses to gauge the real-world costs that climate change is imposing on the U.S. economy.

Getting rid of the measure, called the “social cost of carbon,” would upend energy and environmental regulations meant to address climate change and could have the long-term effect of shifting costs from polluting industries directly onto Americans as the expenses of climate change rise.

The measure essentially establishes a price for each ton of carbon emitted, based on the long-term damages it is expected to cause in the future. It has become the government’s primary tool to weigh the economic costs of climate change — such as disaster cleanup or health impacts from warming — against the burden of regulations.

The executive order disbanded the working group, which included the treasury secretary, energy secretary and director of national economic policy, that set the social cost of carbon and advised how it should be implemented. It revoked that group’s previous decisions. And it directed the Environmental Protection Agency, which calculates the figure and bases regulatory proposals on it, to reconsider using the social cost of carbon altogether with the goal of eradicating “abuse” that stands in the way of affordable energy production.