Biden Rejoins Paris Climate Agreement

WASHINGTON — President Joseph R. Biden Jr. on Wednesday recommitted the United States to the Paris climate agreement, the international accord designed to avert catastrophic global warming, and ordered federal agencies to start reviewing and reinstating dozens of environmental regulations that had been weakened or rolled back by former President Donald J. Trump.

The moves represent a first step in healing one of the deepest rifts between the United States and the rest of the world after Mr. Trump rejected the Paris pact and seemed to relish his administration’s push to weaken or undo every major domestic climate policy.

Mr. Biden has elevated tackling the climate crisis among his highest priorities, vowing that ending the coronavirus pandemic, restoring the economy, addressing racial injustice and curbing global warming will be the four driving causes of his administration.

“A cry for survival comes from the planet itself,” Mr. Biden said in his inaugural address. He said that on climate and a range of issues “We will repair our alliances and engage with the world once again.”

Environmental and foreign policy experts hailed Mr. Biden’s first moves as a powerful signal that the United States, the largest contributor to global warming in history, intends to restart its efforts to lower pollution levels and to restore the international order upended by Mr. Trump. Under the Paris Agreement, nearly 200 nations have vowed to reduce planet warming emissions to avert the worst effects of climate change.

But they cautioned that Mr. Biden’s actions on day one were only a first step — one that must be quickly followed by a series of aggressive domestic climate policy actions to drastically lower the country’s emissions of planet-warming pollution from tailpipes, smokestacks and oil and gas wells.

The lengthy legal process of undoing most of Mr. Trump’s environmental rollbacks and replacing them with new regulations could take many years and is likely to be strewn with political land mines as Republicans or business groups potentially fight against new rules.

Even before Mr. Biden was inaugurated Wednesday, some Republicans lashed out against his new policy direction.

“President-elect Biden’s policies from day one hurt American workers and our economy,” Senator Shelley Moore Capito of West Virginia said in a statement. “Killing the Keystone XL pipeline and rejoining the Paris Agreement will eliminate good-paying jobs.” She called Mr. Bidens plans “virtue signaling” that will come at the expense of low-income and rural families that rely on the oil and gas industry for jobs.

Mr. Biden has set an ambitious target for the United States to eliminate carbon dioxide emissions from the electric power sector by 2035 and from the entire economy by 2050. However, it is far from certain that the United States could reach those goals absent new legislation from Congress — a difficult prospect, given the Democrats’ razor-thin one-vote majority in the Senate.

“Everybody who’s serious about climate change is happy to see us back in the Paris Agreement, but it doesn’t come anywhere near to solving the problem,” said Michael Oppenheimer, a professor of geosciences and international affairs at Princeton University and a member of the Intergovernmental Panel on Climate Change, which produces global reports on the state of climate science. “There’s still a very big chore to be done.”