Energy Seminar | David Keith

The combination of inertia and uncertainty makes the coupled climate-economic system dangerously hard to control. Emissions cuts are necessary to manage climate risks, but they are not necessarily sufficient. If the climate's sensitivity is at the high end of current estimates it may be too late to avert dramatic consequences for human societies and natural ecosystems even if emissions are eliminated instantaneously. Prudence demands understanding of methods that might limit environmental risks posed by the accumulation of fossil carbon in the atmosphere. The engineered alteration of the earth’s radiation budget—solar geoengineering—offers a fast means of managing climate risk, but it entails a host of new risks and it cannot fully compensate for the risk posed by the carbon burden. Professor David Keith will review the science and technology and of solar geoengineering and show new results from climate models, lab experiments, and integrated assessment models.

Speaker Biography:

David Keith has worked near the interface between climate science, energy technology, and public policy for twenty-five years. Best known for his work on the science, technology, and public policy of solar geoengineering, David led the development of Harvard’s Solar Geoengineering Research Program. He took first prize in Canada's national physics prize exam, won MIT's prize for excellence in experimental physics, and was one of TIME magazine's Heroes of the Environment. David is a Professor at the Harvard School of Engineering and Applied Sciences and Harvard Kennedy School, and founder of Carbon Engineering, a company developing technology to capture CO2 from ambient air.

[profcpbl]

This is an honest, passionate, articulate, Bayesian brain on display. Thanks for this helpful, dense lecture, David.

[richjones]

David Keith is a forward-thing, cautious and wise professor, but he really does bring out the fucking crazies in the comments section.

[PnPrailroad]

Also. The last thing we see in this video is: "Sponsored by Chevron Petroleum". That explains a lot.

[danimalplanimal]

isn't this the guy who said "It's not really a moral hazard, it's more like free-riding on your grand kids"? /watch?v=f61DuRkzzRA

[ronaldgarrison]

The scariest thing David Keith said is probably that SRM is relatively cheap, as least compared to the effects. (I'll avoid using the term "benefits, " as it isn't established that they really are.) If that's so, it may be pursued instead of carbon removal. In fact, it may be cheap enough for NGOs to pursue on their own, maybe clandestinely (say, by some agribusiness in some region).

He may be right when he says that Pinatubo wasn't especially bad, so putting sulfates in the stratosphere may not be so bad, either. But to counter 6 degrees of warming, which may be the case if the moral hazard objection holds, may take multiple Pinatubos each year.

Elon Musk has called the CO2 increase the "dumbest experiment ever." But we may be about to do an even dumber one.

How expensive, and slow, is air capture? Keith says it will be very slow. How slow? Let's ballpark it a little. In the last 20 years, CO2 has gone up steadily about 2.5 ppm. Being, I think, very pessimistic, let's suppose it goes up to 500 ppm, which represents about another 30 years at present rates. (I say pessimistic because I think it will peak within 20 years, probably sooner; but we're already at 425 ppm, so 500 is plausible, much as I hate to say it.) Let's say the reduction target is 350. You want to reduce by 150. Let's suppose that, after stopping net emissions, you can reduce by the same amount as it's now increasing: 2.5 ppm/year. That suggests 60 years, after reaching zero net emissions. But in fact, the oceans have been soaking up half of the excess CO2, so when you start removal, you'll have to remove all the excess that the oceans took up as well. So you might expect 120 years.

But it's probably better than that. Pessimism is only justified IMO if energy, and industrial capability, are scarce. And after all, we don't have to atone for all past energy production—only the carbon-based portion. Some of the oil-based energy, most of the gas-based, and the vast majority of all past joules from all other sources (taking into account embedded energy of production), was "innocent." IAC we can probably expect to be going this extraction in the context of a global economy that is, on average, maybe 3X the current one. That makes 40 years (or 60 to 70 years from now) quite reasonable.

It may be better than that, because it may be that carbon capture can be driven mainly from low-grade waste heat.

But it could be long a 40 years, and the temptation to go for a quick fix is something I find increasingly frightening.

[matthewhatfield]

David Keith a very dangerous man that should be stopped at any cost.

[vinnywest]

Oh ok. He said geo engineering doesn't affect human health. Thanks David :)

[PnPrailroad]

Here's a solution David: Let's stop burning stuff and plant & grow vegetation instead. How's that ?

[realeyesrealizereallies]

I cannot believe how many times this fool says, "Might", "Maybe", "May", "Could", Should", "Presume", "Assume". Identified a useless discussion within 3 minutes.

[marynoonan]

Like Oppenheimer, he’s just the academic. The US military are the ones unfolding this climate and weather manipulation plan.

[PnPrailroad]

David starts out saying: Cost of PV solar has come down so much, so let's dim the sun hitting the planet ? So go buy many more PV panels to harvest the same amount of power ? Seems he's playing tug rope with himself.

[DragonBallSuperZ]

Why are we not talking about zero point energy for carbon capture david?

[davidwilkie]

Making Climate change policy sausages? Complicated and messy, but watching the process is vital.