Since his first days in office, President Trump has made eliminating federal regulations a priority. His administration, with help from Republicans in Congress, has targeted environmental rules it sees as overly burdensome to the fossil fuel industry, including major Obama-era policies aimed at fighting climate change.

A New York Times analysis, based on research from Harvard Law School, Columbia Law School and other sources, counts nearly 80 environmental rules on the way out under Mr. Trump. Our list represents two types of policy changes: rules that were officially reversed and rollbacks still in progress. Nearly a dozen more rules – summarized at the bottom of this page – were rolled back and then later reinstated, often following legal challenges.

The process of rolling back regulations has not always been smooth. In some cases, the administration has failed to provide a strong legal argument in favor of proposed changes or agencies have skipped key steps in the rulemaking process, like notifying the public and asking for comment.