Al Gore had just one piece of advice for President Donald Trump - to "resign" immediately.
The former Vice President was promoting his new documentary on climate change when he made the comments to entertainment web site LAD Bible.
He was promoting his new documentary on climate change, An Inconvenient Sequel: Truth to Power.
Mr Gore made these comments before last weekend's violence in Charlottesville and the President's controversial responses to it.
The erstwhile presidential candidate who lost the 2000 presidential race to George W Bush in a battle that ended at the US Supreme Court, has long been an advocate for a stronger American response to global warming, what he called "far and away the most serious crisis we face".
Mr Trump's stance on climate change is to question its existence.
He has promoted Cabinet members like Environmental Protection Agency chief Scott Pruitt and Energy Department head Rick Perry who do not believe human action is a primary cause of global warming and withdrawn the US from the Paris Agreement, a global accord signed by nearly 200 countries to lower carbon emissions and help poorer countries adapt to an already-changed planet.
"They've taken the same playbook as the tobacco industry," Mr Gore said about climate deniers in the US who have spent billions trying to convince people the volumes of scientific studies on climate change is unreliable.