From one former vice president to another, Al Gore on Wednesday endorsed Joe Biden for president, picking Earth Day to formally put his support behind the presumptive Democratic nominee.

Gore announced the endorsement during a climate change virtual town hall hosted by the Biden campaign, calling President Donald Trump "the face of climate denial globally."

"We need policy changes and that means we need to change some of the policymakers, particularly the one in the White House right now. And that's why I am so proud to endorse your candidacy, Joe," Gore told Biden on a split screen.

Gore, who narrowly lost his Democratic bid for president in 2000, has become one of the world's leading climate activists over the past two decades, starring in the movie "An Inconvenient Truth" in 2006 and winning the Nobel Peace Price for his efforts one year later.

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In a 36-minute conversation, Gore told Biden that Trump has lifted constraints on polluters, contributing to more pollution into the atmosphere. He called it "crucial" that Biden win the election and vowed to do "everything I can" to persuade everybody who cares about the climate crisis to back Biden.

"If you want to start solving the climate crisis, this is not rocket science. This is the most consequential choice in a presidential election that we've ever had in American history," Gore said. "This is a no-brainer. This is real simple choice, and if anybody has a doubt about that, come talk to me."

Biden thanked Gore and told him, "Beating Trump won't end climate change but it's a critical first step."

In coordination with Earth Day, Biden also picked up the endorsement of Democratic Washington Gov. Jay Inslee, who made tackling climate change his top issue during his failed presidential run last year.

Before Gore became vice president under President Bill Clinton from 1993 to 2001, he served in the Senate with Biden. As a young congressman in the early 1980s, Gore held some of the first congressional hearings on global warming.

In his talk with Gore, Biden slammed the Trump administration's decision last week to withdraw an Obama-era rule that compelled the country’s coal plants to cut back emissions of mercury and other human health hazards. The move is designed to limit future regulation of air pollutants from coal- and oil-fired power plants.

"It's wrong," Biden said. "It's a step backwards, and as we try to seek some progress, he's eviscerating the EPA and everything that's out there."

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As Gore nodded in approval, Biden called it "particularly dangerous" that communities of color are disproportionately affected by air pollution and the ongoing coronaviarus pandemic.

"It shouldn't be more likely to breathe poisoned air and drink poisoned water based of your ZIP code or the color of your skin," Biden said.

Biden has endorsed much of the framework of the ambitious Green New Deal climate proposal backed by progressive Democrats. But his $5 trillion, decade-long plan to combat the climate crisis, unveiled last summer, falls short in some areas, especially in the timeline he envisions for eliminating carbon pollution from the economy.

Biden has pushed tax breaks, direct spending and more aggressive federal regulations including the reversal of many actions of the Trump administration, which has rolled back a wide range of Obama-era environmental rules. Biden has said he would be more aggressive on the world stage, using U.S. political and economic muscle to limit emissions from other nations, including China.

"There's so much more that needs to be done. Donald Trump has ignored the science and he's literally taken us backwards and the whole world with it," Biden said.

Contributing: Associated Press

Follow Joey Garrison on Twitter: @joeygarrison.