Bill Nye is done messing around. Look out, because while you might not typically associate angry talk with the normally-mild-mannered “Science Guy” Nye, when it comes to the threat of global climate change, he has – understandably, perhaps – lost his patience. And how.

The beloved science educator and television personality, best known for his children’s program Bill Nye the Science Guy, appeared on Last Week Tonight with John Oliver on Sunday in a segment on the plan to fight climate change, and started throwing the F-word about – a lot. (The plan is sponsored by the US House of Representatives’ Alexandria Ocasio-Cortez and the longtime environmental advocate and Senator Ed Markey, and is known as the Green New Deal.)

bill nye just grounded me and sent me to my room and i can’t come out until i make the planet stop melting pic.twitter.com/Uck1Qt2mau — Jarvis Johnson (@jarvis) May 14, 2019

The non-binding resolution, as Oliver pointed out in the segment, has been especially polarizing, and is regularly ridiculed in bad faith by Republicans, despite the scale of the climate-based issues it merely suggests might be a good idea to address, such as carbon-pricing.

In a short bit, Nye appears to explain why that concept might help.

“When something costs more, people buy less of it,” Nye says in a makeshift science lab, cutting to the chase. He goes on to explain why burning less fuel in our cars or burning less coal might help prevent fires, floods, and crop failures. And then he says, because Oliver is a “42-year-old man who needs his attention sustained with tricks, here’s some fucking Mentos in a bottle of Diet Coke”, an experiment with mints and soda that appears to delight the host.

After explaining the idea being carbon taxes, and the difficulty politicians have getting people to accept the idea of a new tax, Nye returns for another experiment to cut through all the talk.

“By the end of this century, if emissions keep rising, the average temperature on Earth could go up another four to eight degrees,” Nye says, losing his patience. “What I’m saying is the planet is on fucking fire,” he says while taking a torch to a globe.

“There are a lot of things we could do to put it out. Are any of them free? No, of course not. Nothing’s free, you idiots. Grow the fuck up. You’re not children any more. I didn’t mind explaining photosynthesis to you when you were 12. But you’re adults now, and this is an actual crisis, got it? Safety glasses off, motherfuckers.”