Dozens of U.S. states, alongside city and county governments, have filed a lawsuit against the Trump administration’s Environmental Protection Agency (EPA), seeking to block the agency from rescinding a rule that allows regulation of greenhouse gases.

The Endangerment Finding, established in 2009, recognizes carbon dioxide and other pollutants as threats to both public health and the welfare of the United States. The finding is used as a legal basis for why the EPA can establish rules and regulations on greenhouse gases.

In February, the agency announced that it would rescind the rule completely, thereby ending the legal justification for myriad regulations and terminating rules on greenhouse gases in one fell swoop.