So I worked out while watching this week’s episode of Cosmos. I’m several weeks “behind”, if it’s possible to be behind for a documentary series (though I’ve DVRed them all for future marathon sessions). But this was a wonderful episode to come back to. It was a really good primer on contemporary understanding of climate change, especially addressing rebuttals from skeptics that have become more common over the last 20 years or so. In particular, I liked these points
- Tyson pointed out that the greenhouse effect is “beneficial” in that Earth would be like 30 degrees cooler without it. But he also points out how little CO2 it takes to get that much of a shift, and how little CO2 we need to add to make temperature change too much.
- It’s not that climate is changing that’s bad, it’s that climate change that is too fast can destroy ecosystems. Tyson pointed out the speed of anthropogenic CO2 emissions isn’t close to anything previously seen in Earth’s history aside from the previous mass extinction believed to be caused by climate change.
- We can in fact figure out the difference between CO2 we’re emitting and CO2 from many natural sources, and that evidence points out most of the new CO2 is from our fossil fuels. How? The CO2 from fossil fuels is made up of carbon atoms that are different weights from what we would otherwise expect in the atmosphere.
- The Sun hasn’t really appreciably changed to cause the temperature increases we see.
- The ocean is warming up. Actually, I’m not sure the show mentioned the “greenhouse pause” people talk about, but what is important to note is that so-called “stop” in air temperatures doesn’t really tell the whole story. The Spaceship of the Imagination gave us an infrared view of the Earth to look at the planet’s heat emissions. We’re finding out that while the atmosphere may not have heated up over this last decade, the ocean definitely has. I’m also surprised the show didn’t mention the potential danger of ocean acidification.
I also loved the presentation of climate as better understood by large scale driving forces and not “just” the average of weather. I don’t know any climatologists, but I’m sure such a simplifying definition of their field has always bugged them. One major factor is energy conservation, and since I took a simple engineering class that tried to stress how much of understanding technical systems is based on just applying various conservation laws, I try to emphasize that more. Those space satellites let us measure how much heat Earth radiates away, and given that the sun’s input is relatively constant, if the atmosphere traps more heat in, then we must be heating up. (This is also the source of my very basic understanding as to why severe weather gets worse under climate change. We’re trapping in more energy, and so storm systems basically get stronger because it goes somewhere.) And I also loved that they tied in how our knowledge of other planets has helped inform our understanding of Earth. (And even gave a shout out to Carl Sagan’s research!) I do have one major peeve, though, and I want to point out that they did commit the cardinal sin of data presentation and not include any scale for the color representing temperature increases on their maps.
I had never heard of Frank Shuman before and now I want to look him up. It amazes me how similar his pointing out a small region of solar power generators could power civilization is to Rick Smalley’s idea, minus the nanotubes. If there’s anything I’ve learned the last two years in grad school while doing literature research for my own project, it’s how freakishly non-linear and coincidental energy research can be. To a more philosophically minded friend, I joked that learning about energy technologies has destroyed the last shreds of my old belief in logical positivism, the idea that human history is generally a linear progression towards more good. But I’ll be darned and say I’m still an optimist and had slight chills hearing JFK’s “We choose to go to the moon” speech with scenes of that (super utopian) city of sustainable energy and green spaces.