President-elect Joe Biden will take office with a plan to adopt tough new climate targets for the US and reverse many of the environmental actions of the Trump administration in a stance that was welcomed by world leaders over the weekend.
Mr Biden, who has pledged to rejoin the Paris climate accord on his first day in office, has called climate change an “existential threat to humanity” and pledged a $2tn green stimulus package to help reduce US emissions.
That would be a dramatic reversal from the position of President Donald Trump, who pulled the US out of the Paris climate deal and weakened environmental rules.
UK prime minister Boris Johnson, in a congratulatory tweet, suggested that climate would be an important area of co-operation between the US and UK, alongside trade and security.
“I think now with President Biden in the White House in Washington, we have the real prospect of American global leadership in tackling climate change,” Mr Johnson told the Associated Press.
Mr Biden has pledged to cut US emissions to net zero by 2050, which would significantly slow down the pace of global warming if implemented.
This would put the Paris accord goal — of limiting global warming to 1.5C — within striking distance “for the first time ever”, according to Bill Hare, chief executive of Climate Analytics, a research group. “This could be an historic tipping point,” he said.
China recently pledged to reach carbon neutrality by 2060, and the EU’s goal is net zero emissions by 2050.
“Welcome back America!” said Paris mayor Anne Hidalgo in a tweet, referring to the US rejoining the climate accord.
“It is a big relief that the US comes back,” said Laurence Tubiana, chief executive of the European Climate Foundation, and one of the key architects of the Paris pact. “The positive domino effect from [the] Biden presidency will be enormous,” she added.
Net zero targets in both the US and China could reduce global warming from 2.7C by the end of the century, to about 2.3C-2.4C, according to projections from Climate Action Tracker, a research group based in Germany.
However, Mr Biden’s domestic climate agenda could be challenged if the Republican party retains control of the Senate, which will be decided by two run-off elections in Georgia in January.
Paul Bledsoe, strategic adviser at the Progressive Policy Institute, and a former climate adviser in the Clinton White House, said Mr Biden could lean more on regulatory measures to enact his environmental agenda, if he were unable to pass climate legislation.
“Trump overturned over 100 major environmental regulations. Many of those will be reinstated,” said Mr Bledsoe. Vehicle emissions standards, which were watered down under the Trump administration, could be one of the first areas to be revived.
A Biden administration is also expected to set up the first National Climate Council, a high-level group whose chair would direct policy across the federal government. Among those tipped as contenders to chair the council are John Kerry, a former secretary of state.
Even with a Republican-controlled Senate, a Biden administration might find common ground with Republicans who are willing to include clean energy in broader economic stimulus measures.
“There is some common ground there,” said Nat Keohane, senior vice-president for climate at the Environmental Defense Fund, a US-based advocacy group. Areas of possible agreement included electric vehicles, decarbonisation of the power sector, and preparing the manufacturing sector for low-carbon technologies.
One of the challenges facing a Biden administration will be to determine new climate targets, once it rejoins the Paris accord. Mr Biden has said he will target net zero emissions by 2050, and for all electricity to be emissions-free by 2035.
However, the Paris agreement would also require the US to set climate targets for 2030, a more near-term goal.
In a tweet late on Wednesday night, Mr Biden reiterated that he would ensure the US rejoined the Paris climate accord on his first day as president. The US formally quit the climate pact on the day after the election was held.