Bill Nye made his name as the titular host of 90s after-school classic, Bill Nye the Science Guy, with his quirky lab-coat-and-bow-tie get up and zany experiments. Today, he is earning himself a reputation as one of the go-to spokespersons for climate science, battling climate skeptics on national TV and urging for more stringent climate change action.

His latest stunt – which involved fire, safety goggles, and a burning globe – has gone viral. Appearing on Last Week Tonight with John Oliver on Sunday, Nye took to the screen to talk about the climate change crisis – and used some very non-PG language to boot. 

"Safety goggles on," said Nye, strapping a pair to his forehead. "By the end of this century, if emissions keep rising, the average temperature on Earth could go up another 4 to 8 degrees."

"What I’m saying is the planet is on fucking fire," he continued, setting a globe aflame to make his point. 

There are ways to put it out, he said, but none of them will be free. "Nothing's free, you idiots. Grow the fuck up," he told viewers. "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 actual crisis, you got it?" 

It's worth mentioning that models predicting the speed and severity of climate change naturally vary due to the unpredictability of certain climatic variables. Melting ice sheets, for example. But a study published last year did find that if nothing is done to curb our enthusiasm for burning fossil fuels, we are on track to see temperatures rise by 4°C (about 7°F) by the end of the century (or earlier).   

Of course, this is bad news for everyone on the planet. Indeed, a landmark report released by the IPCC in 2018 has warned us of the dangers of allowing temperatures to rise by 2°C, let alone 4°C. And while Nye's jokey-but-also-deadly-serious segment has attracted a lot of attention – as one Twitter user said, "I just heard Bill Nye swear and it’s blowing my mind" – he was invited onto the show to discuss ways to stop that 2°C warming from happening.

One of those methods is carbon pricing. 

"When we release carbon, say, by burning coal or driving an SUV, all of us pay for that in the form of things like fires, floods and crop failures," he explained. 

"Putting a fee on carbon creates incentives to emit less carbon, and, more importantly, it also incentivizes the development of low-carbon technology, which is huge, because that's vital to reducing emissions globally."

Host John Oliver mentioned how a carbon tax in his home country (the UK) has seen carbon dioxide fall to the "lowest level since before Mary Poppins danced with chimney sweeps and introduced the Banks children to cocaine."

Both presenters seemed to endorse the Green New Deal, proposed by Rep. Alexandria Ocasio-Cortez (D-NY), with Oliver describing it as "a non-binding resolution that very briefly sets out some extremely aggressive goals, including achieving net-zero greenhouse gas emissions, meeting 100 percent of the country's power demand through clean, renewable and zero-emission energy sources and creating millions of good, high-wage jobs in the United States.

"The whole Green New Deal is just 14 pages long. That is seven pages shorter than the menu for the Cheesecake Factory."