WASHINGTON — In the most ambitious U.S. effort to stave off the worst ofclimate change, President Joe Biden signed executive orders Wednesday totransform the nation’s heavily fossil-fuel-powered economy into aclean-burning one, pausing oil and gas leasing on federal land andtargeting subsidies for those industries.

The directives aim to conserve 30 per cent of the country’s lands andwaters in the next 10 years, double the nation’s offshore wind energy, andmove to an all-electric federal vehicle fleet, among other changes. Biden’ssweeping plan is aimed at staving off the worst of global warming caused byburning fossil fuels.

But his effort it also carries a political risk for the president andDemocrats as oil- and coal-producing states face job losses from moves tosharply increase U.S. reliance on clean energy such as wind and solar power.

“We can’t wait any longer” to address the climate crisis, Biden said atthe White House. ”We see with our own eyes. We know it in our bones. It istime to act.”

He said his orders will “supercharge our administration’s ambitious plan toconfront the existential threat of climate change.”

Biden has set a goal of eliminating pollution from fossil fuel in the powersector by 2035 and from the U.S. economy overall by 2050, speeding what isalready a market-driven growth of solar and wind energy and lessening thecountry’s dependence on oil and gas. The aggressive plan is aimed atslowing human-caused global warming that is magnifying extreme weatherevents such as deadly wildfires in the West and drenching rains andhurricanes in the East.

Biden acknowledged the political risk, repeatedly stating his approachwould create jobs in the renewable energy and automotive sectors to offsetany losses in oil, coal or natural gas.

“When I think of climate change and the answers to it, I think of jobs,”Biden said. “These aren’t pie-in-the-sky dreams. These are concreteactionable solutions. And we know how to do this.”

In a change from previous administrations of both parties, Biden also isdirecting agencies to focus help and investment on the low-income andminority communities that live closest to polluting refineries and otherhazards, and the oil- and coal-patch towns that face job losses as the U.S.moves to sharply increase its reliance on wind, solar and other energysources that do not emit climate-warming greenhouse gases.