||Chemtrails program is not an imaginary conspiracy theory. Speak mad that all this came up.
Environmental scientist David Keith proposes a cheap, effective, shocking means to address climate change: What if we injected a huge cloud of ash into the atmosphere to deflect sunlight and heat?
David Keith studies our climate, and the many ideas we've come up with to fix it. A wildly original thinker, he challenges us to look at climate solutions that may seem daring, sometimes even shocking.
"You've all seen lots of articles on climate change, and here's yet another New York Times article, just like every other darn one you've seen. It says all the same stuff as all the other ones you've seen. It even has the same amount of headline as all the other ones you've seen. What's unusual about this one, maybe, is that it's from 1953. And the reason I'm saying this is that you may have the idea this problem is relatively recent. That people have just sort of figured out about it, and now with Kyoto and the Governator and people beginning to actually do something, we may be on the road to a solution. The fact is -- uh-uh. We've known about this problem for 50 years, depending on how you count it. We have talked about it endlessly over the last decade or so. And we've accomplished close to zip.
This is the growth rate of CO2 in the atmosphere. You've seen this in various forms, but maybe you haven't seen this one. What this shows is that the rate of growth of our emissions is accelerating. And that it's accelerating even faster than what we thought was the worst case just a few years back. So that red line there was something that a lot of skeptics said the environmentalists only put in the projections to make the projections look as bad as possible, that emissions would never grow as fast as that red line. But in fact, they're growing faster.
Here's some data from actually just 10 days ago, which shows this year's minimum of the Arctic Sea ice, and it's the lowest by far. And the rate at which the Arctic Sea ice is going away is a lot quicker than models. So despite all sorts of experts like me flying around the planet and burning jet fuel, and politicians signing treaties -- in fact, you could argue the net effect of all this has been negative, because it's just consumed a lot of jet fuel. (Laughter) No, no! In terms of what we really need to do to put the brakes on this very high inertial thing -- our big economy -- we've really hardly started. Really, we're doing this, basically. Really, not very much.
I don't want to depress you too much. The problem is absolutely soluble, and even soluble in a way that's reasonably cheap. Cheap meaning sort of the cost of the military, not the cost of medical care. Cheap meaning a few percent of GDP. No, this is really important to have this sense of scale. So the problem is soluble, and the way we should go about solving it is, say, dealing with electricity production, which causes something like 43-or-so percent and rising of CO2 emissions. And we could do that by perfectly sensible things like conservation, and wind power, nuclear power and coal to CO2 capture, which are all things that are ready for giant scale deployment, and work. All we lack is the action to actually spend the money to put those into place. Instead, we spend our time talking.
But nevertheless, that's not what I'm going to talk to you about tonight. What I'm going to talk to you about tonight is stuff we might do if we did nothing. And it's this stuff in the middle here, which is what you do if you don't stop the emissions quickly enough. And you need to deal -- somehow break the link between human actions that change climate, and the climate change itself. And that's particularly important because, of course, while we can adapt to climate change -- and it's important to be honest here, there will be some benefits to climate change. Oh, yes, I think it's bad. I've spent my whole life working to stop it. But one of the reasons it's politically hard is there are winners and losers -- not all losers. But, of course, the natural world, polar bears. I spent time skiing across the sea ice for weeks at a time in the high Arctic. They will completely lose. And there's no adaption.
So this problem is absolutely soluble. This geo-engineering idea, in it's simplest form, is basically the following. You could put signed particles, say sulfuric acid particles -- sulfates -- into the upper atmosphere, the stratosphere, where they'd reflect away sunlight and cool the planet. And I know for certain that that will work. Not that there aren't side effects, but I know for certain it will work. And the reason is, it's been done. And it was done not by us, not by me, but by nature.
Here's Mount Pinatubo in the early '90s. That put a whole bunch of sulfur in the stratosphere with a sort of atomic bomb-like cloud. The result of that was pretty dramatic. After that, and some previous volcanoes we have, you see a quite dramatic cooling of the atmosphere. So this lower bar is the upper atmosphere, the stratosphere, and it heats up after these volcanoes. But you'll notice that in the upper bar, which is the lower atmosphere and the surface, it cools down because we shielded the atmosphere a little bit. There's no big mystery about it. There's lots of mystery in the details, and there's some bad side effects, like it partially destroys the ozone layer -- and I'll get to that in a minute. But it clearly cools down. And one other thing: it's fast. It's really important to say. So much of the other things that we ought to do, like slowing emissions, are intrinsically slow, because it takes time to build all the hardware we need to reduce emissions. And not only that, when you cut emissions, you don't cut concentrations, because concentrations, the amount of CO2 in the air, is the sum of emissions over time. So you can't step on the brakes very quickly. But if you do this, it's quick. And there are times you might like to do something quick.
Another thing you might wonder about is, does it work? Can you shade some sunlight and effectively compensate for the added CO2, and produce a climate sort of back to what it was originally? And the answer seems to be yes. So here are the graphs you've seen lots of times before. That's what the world looks like, under one particular climate model's view, with twice the amount of CO2 in the air. The lower graph is with twice the amount of CO2 and 1.8 percent less sunlight, and you're back to the original climate. And this graph from Ken Caldeira. It's important to say came, because Ken -- at a meeting that I believe Marty Hoffart was also at in the mid-'90s -- Ken and I stood up at the back of the meeting and said, "Geo-engineering won't work." And to the person who was promoting it said, "The atmosphere's much more complicated." Gave a bunch of physical reasons why it wouldn't do a very good compensation. Ken went and ran his models, and found that it did.
This topic is also old. That report that landed on President Johnson's desk when I was two years old -- 1965. That report, in fact, which had all the modern climate science -- the only thing they talked about doing was geo-engineering. It didn't even talk about cutting emissions, which is an incredible shift in our thinking about this problem. I'm not saying we shouldn't cut emissions. We should, but it made exactly this point. So, in a sense, there's not much new. The one new thing is this essay. So I should say, I guess, that since the time of that original President Johnson report, and the various reports of the U.S. National Academy -- 1977, 1982, 1990 -- people always talked about this idea. Not as something that was foolproof, but as an idea to think about.
But when climate became, politically, a hot topic -- if I may make the pun -- in the last 15 years, this became so un-PC, we couldn't talk about it. It just sunk below the surface. We weren't allowed to speak about it. But in the last year, Paul Crutzen published this essay saying roughly what's all been said before: that maybe, given our very slow rate of progress in solving this problem and the uncertain impacts, we should think about things like this. He said roughly what's been said before. The big deal was he happened to have won the Nobel prize for ozone chemistry. And so people took him seriously when he said we should think about this, even though there will be some ozone impacts. And in fact, he had some ideas to make them go away.
There was all sorts of press coverage, all over the world, going right down to "Dr. Strangelove Saves the Earth," from the Economist. And that got me thinking. I've worked on this topic on and off, but not so much technically. And I was actually lying in bed thinking one night. And I thought about this child's toy -- hence, the title of my talk -- and I wondered if you could use the same physics that makes that thing spin 'round in the child's radiometer, to levitate particles into the upper atmosphere and make them stay there. One of the problems with sulfates is they fall out quickly. The other problem is they're right in the ozone layer, and I'd prefer them above the ozone layer. And it turns out, I woke up the next morning, and I started to calculate this. It was very hard to calculate from first principles. I was stumped. But then I found out that there were all sorts of papers already published that addressed this topic because it happens already in the natural atmosphere. So it seems there are already fine particles that are levitated up to what we call the mesosphere, about 100 kilometers up, that already have this effect.
I'll tell you very quickly how the effect works. There are a lot of fun complexities that I'd love to spend the whole evening on, but I won't. But let's say you have sunlight hitting some particle and it's unevenly heated. So the side facing the sun is warmer; the side away, cooler.
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