The US midterms made waves Wednesday at a UN climate summit on the shores of Egypt, with activists urging President Joe Biden to take bolder action against global warming regardless of the result.
Campaigners were optimistic that Biden's $370 billion green energy legislation would not be thwarted even if Republicans take one or both houses of Congress.
But with Biden due to join the UN's COP27 climate conference in the Red Sea resort of Sharm el-Sheikh on Friday, they also had a message for the US leader.
"I think it would be a catastrophic mistake if President Biden does not seize this literally once-in-the-universe opportunity now to be the climate president that the world needs him to be," said Jean Su, energy justice programme director at the Center for Biological Diversity, a US environmental group.
"We are literally at the tipping point for an unlivable world," she said at a news conference, urging Biden to phase out fossil fuel production and use his presidential powers to declare a climate emergency.
But Su and others were also pleased to see candidates that campaigned on climate change gain seats in Congress.
"A lot of climate champions did win across states, governorships, legislatures, and more," said Frances Colon, climate policy director at the Center for American Progress.
"What we expect is that they will turn these winds into more climate action," she said.
- Split Congress? -
With a majority of races called, Biden's Democrats appeared to have countered Republican hopes of riding a "red wave" to take full control of Congress.
While Republicans seem on track to reclaim the House of Representatives, Democrats appear to have a decent chance of keeping their Senate majority.
"Republicans really ran on platforms of inflation and increased gas prices," Colon said.
"Being propped up by fossil fuels, election denying, and climate denying really didn't work out so well for them."
Republicans will not be able to reverse the Inflation Reduction Act, Biden's flagship programme to green the US economy.
"What you might see from them is that they try to slow down things, try to present some obstacles to what the Biden administration will do for the next two years," Colon said.
But activists said a Republican victory in the House would endanger Biden's pledge to contribute $11.4 billion to a $100 billion per year fund from rich countries to help developing ones green their economies.
Colon said Democrats need to pass the legislation before the new Congress is sworn in January.
- Trump shadow -
After the new Congress is known, all eyes will quickly turn to the 2024 presidential election, with Donald Trump hinting that he will announce his intentions on November 15.
Climate activists fear a Trump comeback. The former US leader pulled the United States out of the Paris Agreement in 2017 -- a move that Biden reversed as soon as he took office.
"We know that there's a huge climate denier that may announce (his candidacy) pretty soon," said Ramon Cruz, president of the Sierra Club, a major US non-government organisation.
"We knew how difficult that was not only for the US, but for the whole world," he said.
The Sierra Club, which supported candidates in this year's election, already has 2024 on the "horizon", he said.
But one campaigner had a different take on the impact of US elections on the climate agenda.
"The US has acted in bad faith irrespective of elections," said Harjeet Singh, senior adviser at Climate Action Network.
Singh said that, for years, the United States has blocked attempts to create a "loss and damage" mechanism through which rich polluters would compensate developing countries for the destruction caused by climate-induced disasters.
The United States has dragged their feet on the issue, but loss and damage has taken centre stage at COP27 as it was finally put on the official agenda following intense negotiations.
"The US has been an obstructionist, always," Singh said.
"Please look at the US role beyond what happens in this election. It is for the US to change course and be more constructive in its approach."