Former Vice President Al Gore on Thursday called President Trump's withdrawal from the Paris climate agreement "indefensible" and said it makes it more difficult for humans to "solve the climate crisis in time."

"Removing the United States from the Paris Agreement is a reckless and indefensible action," Gore said. "It undermines America's standing in the world and threatens to damage humanity's ability to solve the climate crisis in time. But make no mistake: if President Trump won't lead, the American people will."

Still, the Democrat, who starred in the global warming documentary "An Inconvenient Truth," argued "we are in the middle of a clean energy revolution that no single person or group can stop."

"President Trump's decision is profoundly in conflict with what the majority of Americans want from our president; but no matter what he does, we will ensure that our inevitable transition to a clean energy economy continues," Gore said.

The United States entered into the non-binding Paris climate change agreement with 196 other countries in December 2015.

Trump announced Thursday the U.S. would withdraw from the agreement, which will take four years to complete, and "begin negotiating to re-enter either the Paris accord, or an entirely new transaction on terms that are fair to the United States, its businesses, its people, its taxpayers."

Gore has warned before about taking action before it's too late. In 2006, he famously said "many scientists are now warning that we are moving closer to several ‘tipping points' that could — within as little as 10 years — make it impossible for us to avoid irretrievable damage to the planet's habitability for human civilization."