Former Vice President Al Gore – a global leader in the fight to combat climate change – pointed to the environment on Wednesday as he backed former Vice President Joe Biden’s White House bid.

Gore said that supporting the presumptive Democratic nominee over President Trump is “not rocket science.”

GORE RIPS TRUMP FOR LACK OF ACTION ON CLIMATE CHANGE

“This is the clearest most definitive choice in a national election that the United States of American has ever faced, especially for people who care about the climate,” Gore said in an interview with The Associated Press.

“If there is any person in America who cares about the climate crisis and has any doubt whatsoever about the importance of voting for Joe Biden this November, I want to emphasize to that person in as strong a way as I possibly can: This is not complicated,” Gore added. “This is not rocket science. This is not a close call."

Gore’s endorsement – which he made in the interview and in a tweet – came on the 50th anniversary of Earth Day, which is celebrated each year to demonstrate support for environmental protection. Gore later teamed up with Biden later on Wednesday for a virtual town hall on climate change.

"Your election is actually crucial Joe and I want to do everything I can to convince everybody that cares about the climate crisis.. that this is a no brainer, that this is a real clear choice," Gore emphasized as joined Biden. "And if anybody has any doubt about that, come talk to me."

The endorsement of the former vice president by one of his predecessors came a couple of hours after Biden also landed the backing of Washington state Gov. Jay Inslee, one of the Democratic Party’s top crusaders for environmental action.

INSLEE ENDORSES BIDEN AFTER CLIMATE CHANGE CONVERSATIONS

Then-Vice President Gore lost the 2000 presidential election by an extremely narrow margin to then-Texas Gov. George W. Bush in a controversial contest that was decided by a Supreme Court ruling.

Gore’s long been an advocate for combating climate change – dating back to his days as a young congressman from Tennessee in the 1980s – when he called for hearings on global warming.

After leaving the vice presidency, Gore went on to win the Nobel Peace Prize for his environmental activism and won an Academy Award for his documentary, "An Inconvenient Truth."

Fox News' Allie Raffa contributed to this report