This week on Cosmos: A Spacetime Odyssey, Neil deGrasse Tyson finally broached the topic of climate change, and it was truly terrifying. But in addition to scaring the living fossil fuels out of us, Tyson also delved into the alien wonders of Earth past, present, and future. 

Nobody's fault but our own

Abby: Although tonight’s episode stayed away from the current political debate over climate change until the end, we kind of saw it coming as Tyson described the biggest mass extinction event in history: the Permian–Triassic, from which life on Earth took as many as 10 million years to recover. The way Tyson told it, scientists believe “coal smoke” resulting from volcanic activity in the Siberian Traps produced a deadly “witches brew" that helped to warm the climate and push the Earth nearly to extinction. In other words, there’s more than just recent data telling scientists that coal-burning industries could be behind climate change: there’s the Earth’s own fossil records. 

Danielle: We finally got the climate change episode, and it was expertly done. I think Tyson really managed to show just how terrifying global warming is, and did so without allowing any space for climate change skeptics. This is kind of becoming a signature move for him, and it's one I really like.

Abby: Right. It's also one of the things that owes a bit of its success to the original Cosmos series. Like Tyson, Sagan had a few overarching themes that surfaced again and again. 

Danielle: But before we delve more into the climate change stuff, I think we should spend some time on what Tyson discussed in the first half of the episode. Like those massive, alligator-sized, oxygen-fueled centipedes, and the subterranean forests that trapped carbon within the Earth. I love when Cosmos focuses on this planet, and the drastically different forms it has taken -- and will take.

Abby: It's about perspective. While there's an easy sense of wonder that comes from, say, watching Tyson's ship imagine what it will look like when our entire galaxy collides with a neighbor, our day-to-day perception of the cosmos is Earth. And we know it less than we assume, as is becoming more and more clear as the episodes continue. At one point, Tyson mentions that fewer humans have been down to the Marianas Trench on the ocean floor of our own planet than have been to the Moon. 

Danielle: I’m so glad that another female scientist, Marie Tharp, was mentioned in this episode -- with just the right amount of acknowledgement that she’s a woman. Last week we took issue with how the “women’s” episode played out, but this time I think there was a pretty fair balance. Tyson talked about Tharp as an influential scientist who happens to be a woman, but also as one who should be recognized as a scientist who overcame sexism to contribute to her field.

Abby: Yes agreed. It seems to me that Cosmos has been better about applying the social commentary it made on sexism and social bias in science than they were at articulating it last week. In this episode, Tyson made his point very clear when he briefly placed the scientific method in tension with the scientists who practice it, using Tharp as an example. The method, he said, is at its heart a way to reduce human error, blindness, and bias in scientific work as much as possible. But it's hardly instant or complete, which is why every single episode of this show has clearly featured (and sometimes criticized and commented upon) the social context in which discoveries that have propelled us closer to an understanding of the world were made. Often, that human propensity for error or willful ignorance has come from external, powerful institutions, like the Roman Catholic church at its peak of influence. But with Tharp, the call was coming from inside the house. 

Danielle: Definitely. Speaking of challenges to female scientists and awkward segues, I find life in the deep sea to be totally fascinating. As crazy as it is to think about the depth and reach of the cosmos, it’s even crazier to think about how much of the earth is alien to us. We share a planet with animals that don’t need sunlight to live and survive off of bacteria spewing from hydrothermal vents.

The inhospitality of the deep sea is yet another reminder of how foolish it is for us to pump fossil fuels into our air -- not only is Earth the only place in the known universe that our kind could survive, but most of Earth is also hostile to human kind. When you think about, as Tyson instructed us to do throughout the episode, how unlikely it is for us to have survived thus far and how tiny our swathe of this planet practically is, our willingness to throw it all away seems even more stupid than usual. I hope the EPA was watching last night.

Abby: Ha ha, oh man, Danielle. After this week's episode, there are going to be plenty of Cosmos hate-watchers who think the EPA must be secretly funding the show, along with the lamestream media and Al Gore and Soros and Satan, probably. 

Danielle: Ugh, seriously. Tyson may as well have been speaking to the haters directly with a rather stern warning to ditch the head-in-the-sand attitude towards climate change, saying “The dinosaurs never saw the asteroid coming. What’s our excuse?”

Abby: I felt like Tyson was treating a section of his audience like Ebenezer Scrooge, working through the past, present, and future of climate change. At one point, Tyson just straight-up points us down a future corridor in the "Hall of Extinction," with the ominous warning that it might be our turn next. It's as if The Ghost of Climates Future instructed America to wipe the snow off of a tombstone, only to see an engraved image of a crying eagle in the marble. I doubt anyone who isn't already on board with the consensus of science on climate change will have changed minds from Tyson's tale, but it does seem to be a more widespread strategy. 

Danielle: Yes, NASA is using this line as well, although to a slightly different end. During this year’s SXSW conference, NASA reps ran a panel called “Are We Smarter Than the Dinosaurs?” during which they discussed the importance of the agency’s asteroid mission, and called on citizen scientists to contribute to the effort to track asteroids. They say that the only way to make sure that we’re not wiped out by a city-sized asteroid is to try to map out as many of the Earth-bound space rocks as possible, so that NASA can blast them off course if needed. Which is not the most pleasant way to think about our mortality, but is probably the smartest.

But what did the Internet say?

People seemed to embrace the (not discussed, but obvious) political side of climate change: 

And some also noticed another little challenge to religion:

And NASA, as usual, shared some of its awesome pictures:

What we learned

Abby:  That the mediterranean sea was essentially created, or at least re-flooded into existence as the body of water we know today, in less than a year. 

Danielle: I had no idea that scientists expect the contents to drift back together, Pangea style. Talk about globalization, amiright? Although based on this episode it seems highly unlikely that humans will still be around when that happens, hypothetically in about 250 million years.

Check out our discussions of previous Cosmos episodes below: 

Episode one: What Does Neil deGrasse Tyson's Cosmos Say About Religion?

Episode two: Neil deGrasse Tyson Addresses Creationists' Evolution Fears in Cosmos

Episode three: Neil deGrasse Tyson Makes Us Feel Inadequate on This Week’s Cosmos

Episode four: Neil deGrasse Tyson Says Time Travel Is All Around Us on This Week’s Cosmos

Episode five: Neil deGrasse Tyson Shows Us How to See Sounds on This Week's Cosmos

Episode six: Neil deGrasse Tyson Shrinks the Scale on This Week's Cosmos

Episode seven: Neil deGrasse Tyson's Cosmos Explains How we Got The Lead Out of Our Environment 

Episode eight: This Episode of Neil deGrasse Tyson's Cosmos Was for the Ladies