Pumping Particles Into the Atmosphere: A Global Warming Doomsday Device?

In our last post, we discussed why cooling the planet with sun-blocking atmospheric particles wouldn't do much good if an excess of carbon dioxide still turned the oceans to acid.

"Fine," I hear you saying. "How about we use the particles and cut back on the gases? Maybe the particles will buy us the time we need to that." It sounds pretty good -- and, according to Ken Caldeira, it'd be relatively easy to do:

The amount of material that Mount Pinatubo put up into the stratosphere would be enough, if sustained in the stratosphere, to compensate for a quadrupling of CO2. It's twice as much as needed to compensate for doubling.... The flow rate that you'd have to introduce particles into the stratosphere would be on the order of 25 liters per second, which could be sustained by a single firehose. Essentially a single hose or pair of hoses, suspended by balloons, repeated by pumps, would be enough to reverse the globally averaged effects of global warming.

Why not do it, then? Well, in part because a lot of research is still needed to make sure there aren't any unintended and catastrophic consequences. (As in, "Sorry about that, India! My bad," or "Hmm, I wonder why all the plants are so brown and sickly these days?")

But let's assume we get those kinks worked out -- after all, the world didn't go to hell in a handbasket after Mount Pinatubo exploded. (Or, at least, it didn't go to hell because Mount Pinatubo exploded. 1991
sure looks nice these days, don't it?) In that case, the danger is likely to come from prematurely stopping the particle-seeding project.

Even if the world, particularly the United States and China and assorted developing countries, get very serious very quickly about cutting their greenhouse gas emissions, it's going to take decades to reach a sustainable level. The CO2 we've already released is going to stick around in the atmosphere for centuries after that. And if the particle hose doesn't stay running, says Caldeira, the warming effects of that CO2 are going to be felt. Fast. He calls it the "backlash effect."

Over the decade after you stopped, you could experience climate change
20 times more rapid than what we are experiencing now. This is, in general, an area of concern. When we drive our cars today, one-quarter of that CO2 will be in the atmopshere 1000 years from now. If you're saying that you're going to negate the climate effects of your automobile driving by geoengineering, you're committing people 1000
years from now to throwing particles into the stratosphere.

So is that reason to abandon such plans altogether? Well, that's up to you to decide. Personally, I'm pretty creeped out by the thought of humanity's fate hinging on the maintenance of a few pipes is pretty scary. (He who controls the pipe ... controls the world! And talk about a target for terrorists.) But there does seem to be good reason to insist that these plans not be carried out by whoever has the money and inclination to do so. Would you really trust, say, Microsoft to keep something running for a thousand years? Or some startup carbon offset company? Or the government of Cyprus? Or even the United States? Ultimately, these need to be global decisions.

Image: The Alpha-Omega bomb from Planet of the Apes. It's not easy to find doomsday device images, dammit!

See Also:

• An Umbrella Big Enough to Cool the World
• Fighting Climate Change: Engineer First, Ask Questions Later?
• Could Huge Underwater Pipes Reverse Global Warming? - wired.com
• Geoengineering Not a Free Pass to Pollute