Reason

What are the potential effects of changing or keeping air pollution rules on our environment and health?

EPA's reversal of the formal 2009 scientific finding that greenhouse gases threaten humans looks slated to land this week, per the WSJ, other reports, and people tracking the move. Why it matters: Rescinding the "endangerment finding" is the Trump administration's most direct effort yet to rip out climate regulations root and branch — and make it harder for a successor to impose new ones. The big picture: EPA did not confirm the timing, but pointed to Administrator Lee Zeldin's comments in the WSJ piece. "This amounts to the largest act of deregulation in the history of the United States," Zeldin tells the paper. "The final rule will be published once it has completed interagency review and been signed by the Administrator," EPA told Axios on Tuesday. The rule is certain to draw litigation that will play out over years. State of play: The agency is planning to remove the finding with respect to motor vehicle emissions specifically. But that could bring challenges to regulation of emissions from power plants, oil and gas sites, and beyond. What we're watching: The White House Office of Management and Budget website still lists the rule as under review. Meetings with outside parties looking to influence the plan are scheduled through Thursday, but that's not proof of anything