Democratic presidential contender Joe Biden has set out an ambitious $2tn (£1.6tn) green energy plan to create carbon-free electricity by 2035.
The proposal to reduce emissions in the US would see investment in clean energy infrastructure over a four-year period.
"Let's not waste any more time," Mr Biden said at a campaign event in his home state of Delaware on Tuesday, adding: "Let's get to work, now."
His focus on climate issues is in contrast with President Donald Trump.
Mr Trump has previously called climate change "mythical" and "an expensive hoax", but also subsequently described it as a "serious subject".
"When Donald Trump thinks about climate change, the only word he can muster is hoax," Mr Biden said at the Build Back Better campaign event in Wilmington. "When I think about climate change, the word I think of is jobs."
The former vice-president added: "We're not just going to tinker around the edges."
Mr Biden's campaign staff said they would provide details of how the plan to "produce power without producing carbon pollution" would work and how it could be funded in the coming weeks.
The Democratic presidential candidate has previously pledged to raise taxes on large corporations and reverse Mr Trump's tax cuts for high earners.
Mr Biden also said he would re-join the Paris climate agreement, which Mr Trump withdrew the US from in 2017.
As election day approaches and his polling lead holds firm, Joe Biden is getting more ambitious with his proposed first-term presidential agenda.
The latest move, addressing the threat of climate change, targets a top issue for many in the liberal grass roots of the Democratic Party.
The former vice-president's original proposal, unveiled last year, included spending $1.7tn on infrastructure and green jobs over 10 years. It was largely rejected by environmental activists as too little, too slowly.
His latest plan, $2tn over four years, is getting a much more enthusiastic reception, including from groups like the Sunrise Movement, which endorsed Bernie Sanders in the Democratic primaries and have viewed Mr Biden with scepticism.
At the very least, Mr Biden's announcement could help shore up his political left flank as he prepares to face off against Donald Trump in November.
Conservatives have been quick to condemn the plan as big-government profligacy, but the scope of Mr Biden's proposal could reflect rapidly shifting views on what is possible in a political world reshaped by the coronavirus.
Massive government spending and trillion-dollar budget deficits are already a reality. Mr Biden's goal, with his big-ticket climate-change proposal, is to keep the fiscal ball rolling toward his party's priorities.
Responding to Mr Biden's proposal, Trump campaign spokesman Hogan Gidley said it read "like a socialist manifesto that promises to massively raise taxes, eliminate jobs in the coal, oil or natural gas industries, and crush the middle class".
"There is no way he can sell this radical agenda to union workers in energy-producing, manufacturing, or auto industry states like Pennsylvania, Ohio, Michigan, or Wisconsin," Mr Gidley added.
The economy is expected to be a key theme of the 2020 US presidential election, which is due to be held on 3 November.
It will take place following the fallout from the coronavirus pandemic, which has pushed tens of millions of Americans into unemployment.