WASHINGTON (AP) — In the most ambitious U.S. effort to stave off the worst of climate change, President Joe Biden signed executive orders Wednesday to transform the nation's heavily fossil-fuel powered economy into a clean-burning one, pausing oil and gas leasing on federal land and targeting subsidies for those industries.

The directives aim to conserve 30 percent of the country's lands and waters in the next 10 years, double the nation's offshore wind energy, and move to an all-electric federal vehicle fleet, among other changes. Biden's sweeping plan is aimed at staving off the worst of glo...