Is geoengineering a scary or sensible solution?

Some scientists want to add sulphur particles to Earth's atmosphere

Ken Caldeira is a climate scientist who recently ended up on Rolling Stone’s list of “100 People Who are Changing America.” To be correct, Caldeira’s contemplating changing the atmosphere. He advocates furthering research on geoengineering – intentionally altering Earth’s climate.

Caldeira admits that geoengineering is a very risky endavor, and not something we would try without very good reason. But he told me that the threat of a climate crisis – such as worldwide famine – looms larger every day, as the world continues to delay taking major action to cut emissions. “So we need to ask ourselves, if we did confront a climate crisis, what would be our emergency response plan?” Caldeira said.

A climate emergency response plan isn’t as easy as pointing out the exit signs in your building. Creating a means to cool down the climate – even temporarily – is fraught with potential for unintended consequences. Caldeira has been creating climate models to see what would happen if humans were to to shoot sulfur dust into the atmosphere, mimicking a volcano eruption. He said the models show that this scheme would turn down the global temperature, but there is no way that scientists can imagine or enter into the model every possible bad effect (see the “cat effect” on Macquarie Island).

So what Caldeira thinks we should conduct what he calls, “small scale field tests.” This would allow scientists to see how these geoengineering proposals actually interact with the environment. Yet he said it may be “politically risky” to suggest advance research. Indeed, John Holdren, Obama’s scientific advisor, found himself in hot water last week, when he mentioned in an interview that we should consider geoengineering schemes. Both Holdren and Caldeira emphasize that geoengineering is no substitute for serious work on curbing greenhouse gas emissions, and should only be considered in a desperate situation.

I asked Caldeira if geoengineering needs a scientific consensus, much like the consensus on climate change itself. He gave me a mixed answer: In some ways, geoengineering may be effective because it doesn’t require everyone on the planet to change their practices – instead, perhaps a consensus between government leaders. “It’s much easier to deploy from a practical point of view, even though it’s more scary,” Caldeira said.

But on the other hand, Caldeira added, it’s possible that one country may essentially decide to “go at it alone” to alter the climate. Such an action could be unbelievably disastrous, especially if the science behind it has not been confirmed.

As scary as geoengineering and the implications are, if we have the means to alter the climate, research and a regulatory framework are necessary. Caldeira seemed to imply that we’ve already made an important choice. He said, “We need a discussion of how we handle the global commons – do we see our future as one where we learn to live in harmony with the natural geochemical cycles and the natural climate system? Or are humans going to dominate planet and alter it for our own ends? The second path seems to be the one we’re heading down and it’s extremely risky.”

Image Credit:

April 13, 2009

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