The endangerment finding underpins the EPA's ability to regulate greenhouse gases. The Trump administration is trying to reverse it.

In 2009, the Environmental Protection Agency declared that the rising concentrations of greenhouse gases in the atmosphere threatened public health and welfare. This “endangerment finding,” as it’s known in legal jargon,

The Trump administration is releasing its proposal to undo the “endangerment finding,” the long-standing rationale and legal imperative for regulating greenhouse gases under the Clean Air Act