Democratic presidential candidate Beto O'Rourke announced a $5 trillion plan to fight climate change, in his first detailed policy rollout to date.

O'Rourke, whose Iowa rollout in March grew criticism for being light on specifics, said on his campaign website that 80 per cent of the funds would go toward research in order to 'rapidly achieve net-zero emissions while growing our economy.'

He is calling for net zero emissions by 2050 and getting halfway there by 2030 – a similar goal but with a lengthier timetable than Rep. Alexandria Ocasio-Cortez, whose 'green new deal' calls for reaching zero emissions within a decade.

O'Rourke says the plan is needed to keep Earth from sliding past the point of no return in less than a generation.

The former Texas congressman unveiled his proposal on Monday from California's Yosemite National Park, a dramatic backdrop for a move he hopes can jumpstart a campaign that began to much national fanfare but has seen some of that luster fade in recent weeks.

The plan calls for increasing taxes on 'corporations and the wealthiest among us' and 'ending the tens of billions of dollars of tax breaks currently given to fossil fuel companies' while offering federal grants to encourage innovative improvements in housing and transportation.

Democratic presidential candidate and former Texas congressman Beto O'Rourke visited Yosemite National Park and unveiled his $5 trillion plan to combat climate change

However the revenue provisions he mentions lack detail. O'Rourke claims it will be paid for by 'structural changes' to the tax code dealign with corporations and ending oil company tax breaks.

O'Rourke tweeted Monday: 'Climate change is the greatest threat we face. And we won't solve it with half measures or half the country. It will take all of us. That's why I just announced an historic, ambitious plan to meet this challenge and invest in our communities.'

His caution against 'half measures' comes even as even as one of his plan's central features calls for reducing carbon emissions by half by 2030.

Beto O'Rourke visits Yosemite National Park to talk about his historic climate action plan

O'Rourke snaps a selfie at Yosemite National Park on a day he unveiled his climate plan

The plan includes $1.5 trillion in direct federal funding, while seeking to incentivize an additional $3.5 trillion from states, private capital and other sources over 10 years to improve aging infrastructure nationwide and to take 'significant actions to defend communities' preparing for intensified floods, droughts, hurricanes, fires and other natural disasters fueled by a changing climate.

Like others in the packed field of Democrats seeking the White House, O'Rourke promised to sign climate change-fighting executive orders on the first day of his presidency - including rejoining the 2016 Paris Agreement, from which President Donald Trump withdrew the U.S.

O'Rourke cautioned against 'half-measures' to combat climate change

The plan is O'Rourke's most detailed proposal to date

Like the plan proposed by Alexandria Ocasio-Cortez (D-NY), O'Rourke is calling for steep reductions in carbon emissions

'Climate change is the greatest threat we face,' O'Rourke tweeted

And, aligning with the Green New Deal , an ambitious but long-shot initiative backed by some of the most liberal Democrats in Congress, O'Rourke's proposal calls on the U.S. to guarantee net-zero carbon emissions by 2050, while promising to reach half that goal in just the next 11 years.

'This is the most ambitious climate plan in the history of the United States,' O'Rourke said on a video from Yosemite that he posted on Twitter. He has for weeks warned that the U.S. and the world only have a few years to act before damage to the climate becomes nearly irreversible, and he called the issue his top priority.

O'Rourke's plan will find a receptive audience in California. The state has set a goal of generating 100 percent of its electricity from noncarbon sources by 2045 and achieving 'carbon neutrality,' meaning it takes as much carbon dioxide out of the air as it emits.

The announcement comes amid O'Rourke's first visit as a presidential candidate to California, a state that's experiencing more destructive and deadlier wildfires due in part to climate change. A blaze last summer caused a partial shutdown of Yosemite, and O'Rourke on Sunday met privately with firefighters in Mariposa County who battled it for weeks.

Shunning the lucrative fundraisers that commonly bring presidential contenders to California, O'Rourke drove hours from San Francisco, where he held a town hall on Sunday, to Mariposa, home to fewer than 20,000 people and, in the 2016 presidential primary, only about 6,000 voters.

Democratic presidential candidate and former Texas congressman Beto O'Rourke speaks at the University of Nevada, Las Vegas, during a campaign stop Friday, April 26, 2019, in Las Vegas. (AP Photo/John Locher)

Former congressman and Democratic presidential candidate Beto O'Rourke answers questions during a presidential forum held by She The People on the Texas State University campus Wednesday, April 24, 2019, in Houston. (AP Photo/Michael Wyke)

He was similarly encountering few voters on his early morning walking tour of Yosemite, designed to learn about the effects of climate change on the park, 1,200 square miles (3,100 square kilometers) known globally for breathtaking waterfalls and giant sequoia trees. He then planned to drive to the Central Valley to meet with college students, a staple of his campaign.

The trip is consistent with the do-it-yourself campaign style that gave O'Rourke an unorthodox credibility with supporters in Texas and beyond. Californians contributed more than $5.5 million to his unsuccessful Senate bid last fall, second only to Texans in giving to the campaign.

The state's big donor bases in Silicon Valley and Hollywood often function as ATMs for presidential hopefuls, and candidates such as Minnesota Sen. Amy Klobuchar, South Bend, Indiana, Mayor Pete Buttigieg and California Sen. Kamala Harris are already tapping in. Former Vice President Joe Biden, who entered the race Thursday, has planned two fundraisers in May.

'It is unusual to come to California, where there are so many Democratic donors, and decide not to raise money,' said Rose Kapolczynski, who managed former U.S. Sen. Barbara Boxer's campaigns. 'Maybe he's doing so well online that he thinks he can not raise money on this trip and try to make a point of wanting to talk to people instead.'

O'Rourke opened his campaign last month to large crowds in key early states such as Iowa and New Hampshire but also in battleground areas that included Pennsylvania, Michigan and Ohio, as well as solid early fundraising . But, as the initial curiosity surrounding the onetime punk rock guitarist has subsided, O'Rourke has seen some of the buzz around his upstart campaign die down.

He may be hoping his I'll-campaign-anywhere style is novel enough to sprawling California to gain fresh buzz. The state moved its 2020 presidential primary to March with the goal of gaining more sway in the nominating contest. But with nearly 40 million people to reach in California alone, breaking through is tough for any candidate.

'We're the black hole of politics,' said Bob Mulholland, a Democratic National Committee member from Northern California who is supporting Harris. 'Almost anything you do in this state, no one notices.'