Do you hear the latest news about geoengineering proposals and wonder if you tripped and fell through the looking glass? I do. Adding to the vertigo is an article from New Scientist that asks, Hacking the planet: who decides?:
Proposals to cool the Earth by deploying sunshades or sucking carbon dioxide from the atmosphere were considered fanciful just a few years ago, but are now being considered by politicians in the US and UK. At a gathering of key scientists and policy experts held in Asilomar, California, last week, detailed debates began over who should control the development of a planetary rescue plan.
The sense at the meeting was that drastic emissions cuts are the best way to limit the catastrophic droughts and sea-level rises that global warming is expected to cause. But the failure of December’s summit in Copenhagen, Denmark, and the relentless rise in global CO2 emissions have persuaded many to reluctantly consider geoengineering solutions (see diagram, right).
…
Oliver Wingenter at the New Mexico Institute of Mining and Technology in Socorro presented details of an ambitious plan to shift westerly winds. Temperature and pressure changes over the Southern Ocean are thought to have pushed these westerlies 3 to 4 degrees south over the last 50 years. This shift strengthens the ocean currents that bring warm, salty water to the surface, where it accelerates the melting of Antarctic ice.
Wingenter proposes seeding the Southern Ocean with particles of iron to boost phytoplankton growth. Plankton release a chemical called dimethyl sulphide into the atmosphere which helps cloud droplets form. More droplets mean whiter clouds that bounce more solar energy away from Earth. Wingenter calculates that it would be possible to cool regional temperatures by 0.5 ˚C, which could push the westerlies back towards their original position.
Little is known about the side effects, however. Cooling a small region by 0.5 ˚C could dramatically change rain patterns. The impact of plankton blooms on ocean life is also poorly understood. Computer models can go some way to filling in these blanks, and Wingenter foresees at least 10 years of computer studies before field tests could kick off. Other solutions could be field-tested sooner, raising the delicate question of whether such experiments should be allowed in the first place, and what forms they could take.
…
There is one geoengineering solution that almost everyone would like to see work. If carbon dioxide can be removed from the air and stored safely underground, we might be able to stave off the worse effects of climate change.
The big problem is that sucking CO2 out of the atmosphere is expensive: many estimates put the cost at close to $1000 for each tonne captured.
It might, however, turn out to be a lot cheaper than that. In October 2009, David Keith, a climate and energy researcher, founded Carbon Engineering in Calgary, Alberta, Canada. The firm aims to build a device to captureCO2 at economically viable prices. He claims his device will draw down a tonne for US$100 to $250.
If you said “no” to my looking glass question, now might be a good time to rethink that.
The diagram mentioned above is reproduced below. Notice that there’s no distinction made between those approaches that reduce warming and those that attack the core problem, the CO2 level in the atmosphere. I have no further information about what was said at the conference, but I hope that they made a point of talking about geoengineering in at least these two categories. The reason is ocean acidification, of course. Even if you assume we can use orbiting sunshades or some other technique to reduce warming without making some really horrific mistake along the way, such as tripping over an unforeseen side effect, we will have addressed only half of the emissions problem. Minimally, ocean acidification threatens the food supply for hundreds of millions of human beings.
The politics of geoengineering is even more problematic than the article suggests. International relations will certainly be a challenge, to put it mildly, but I would expect to see some horrendous fistfights within some countries. I live in the northeast US, a place that’s packed with people who would be eager for “just a few degrees of warming.” Anyone who thinks that the recent health care reform mud wrestling event here was contentious should be prepared for a much uglier and bigger show if we ever have to debate the US’s participation in geoengineering.
The future is going to be a lot of things, but dull ain’t on the list.
Excellent graph! Thanks.