Bill Nye says President Donald Trump s anti-science policies could have devastating ramifications for the environment and humanity.

The celebrity scientist railed against Trump administration climate change skeptics Monday during a Facebook Live interview with Sen. Bernie Sanders (I-Vt.), an outspoken advocate for climate action and renewable energy development.

The longterm implications are potentially catastrophic, Nye told the 2016 presidential candidate. The problem is the speed at which the world is warming. Its not that the climate is changing its the rate.

Nye, best known for hosting the popular 90s childrens television show Bill Nye the Science Guy and the upcoming Netflix series Bill Nye Saves the World, went on to explain the damaging consequences of ignoring climate change.

Half the people in the world live near coastlines. As the ocean gets a tiny bit warmer, it gets a tiny bit bigger. But the ocean is big and a tiny bit is huge, Nye said, referencing scientific reports that show rising sea levels caused by climate change could engulf many major cities.

The Earths temperature has surged in the recent decade : 2016 was the hottest year on record and January 2017 was 3.5 degrees Fahrenheit above the 20th century average . A report from the Copernicus Climate Change Service earlier this month found that the average global surface temperature soared to 58.6 degrees Fahrenheit in 2016, approximately 2.3 degrees Fahrenheit above pre-industrial times.

Sanders, who holds positions on the Senates energy and environmental committees, hosted the live stream on his Facebook page to help viewers better understand the global crisis of our time.