(CNN) Bill Nye wants to remind you of the seriousness of global warming and he's not mincing words.

The well-known science commentator appeared on "Last Week Tonight with John Oliver" on Sunday and put things bluntly while talking about the Green New Deal , introduced by Rep. Alexandria Ocasio-Cortez and Sen. Ed Markey.

Nye wants you to know, "The planet's on f***ing fire."

"By the end of this century, if emissions keep rising, the average temperature on Earth could go up another four to eight degrees," Nye said. "What I'm saying is the planet's on f***ing fire. 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 f**k up. You're not children anymore. I didn't mind explaining photosynthesis to you when you were 12. But you're adults now, and this is an actually crisis, got it? Safety glasses off, motherf***ers."

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