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 December 17, 2009
Resisting the Dangerous Allure of Global Warming Technofixes

 

As the world weighs how to deal with warming, the idea of human manipulation of climate systems is gaining attention.  Yet beyond the environmental and technical questions looms a more practical issue: How could governments really commit to supervising geoengineering schemes for centuries?

Yale.360 In the summer of 2006, geoengineering - the radical proposal to offset one human intervention into planetary systems with another - came roaring out of the scientific closet. Deliberate climate modification, as climate scientist Wally Broecker once noted, had long been "one of the few subjects considered taboo in the realm of scientific inquiry."

Two things spurred this dramatic reversal: growing alarm because climate change was hitting harder and faster than expected and the abysmal failure of political efforts to reduce carbon dioxide emissions. Indeed, since world leaders signed the Rio Convention on Climate Change in 1992, global emissions climbed from 6.1 billion metric tons of carbon a year to 8.5 billion tons in 2007.

Dismayed by the inaction, Paul Crutzen, a Nobel laureate, published a controversial paper in August, 2006 that opened the door to the hitherto unthinkable. Since timely and sufficient reductions appeared to be, in his words, "a pious wish," he urged serious investigation of technological proposals to offset rising temperatures.

For some, geoengineering seemed to hold out another hope: that technology might provide an escape not only from growing heat, but also from the thorny realm of hard choices and difficult international politics. Those politics were on vivid display in Copenhagen this week, as nations have agreed on the gravity of the threat but little else.

Since the release of Crutzen's influential paper, many have voiced concerns about possible hazards posed by geoengineering schemes. For example, the artificial volcano projects, which would inject sulfate particles into the stratosphere to deflect incoming sunlight, might reduce the symptom of excess heat, but experience from past volcanic eruptions and climate models indicates that this approach would likely alter rainfall patterns and intensify drought in many regions. The moral and political hazards of geoengineering are as formidable as the physical dangers.

And because such sunshade schemes only treat a symptom rather than tackle the cause, this technofix would do nothing to prevent another dire consequence of rising levels of carbon dioxide in the atmosphere - increasing acidity in ocean waters. This acidity jeopardizes coral reefs, shelled marine life, and a tiny plankton Emiliania huxleyi, which plays a key role in the transfer of carbon from the atmosphere to long-term storage in deep ocean sediments.

But the biggest hitch in sunshade remedies involves politics and questions of governance, for they would require an unflagging commitment of centuries: five hundred years or so, or, if we do not make major emissions cuts, even as long as a millennium. If anything were to interrupt this geoengineering effort, which would have to keep replenishing the sulfates every few years, the world would quickly confront a doomsday scenario: Temperatures would suddenly soar upward at a rate 20 times faster than they are rising today, causing unimaginable havoc in human and natural systems and with it, the real danger of human extinction. This institutional challenge is without question a far greater obstacle than any technological difficulties. It is hard to imagine that anyone with even a passing knowledge of human history would think this long-term commitment could be a prudent gamble.

The moral and political hazards of geoengineering are altogether as formidable as the physical dangers. However inviting the prospects shimmering on the technological horizon, geoengineering "solutions" and the promise of a technofix down the road lead us easily into temptation. Indeed, these speculative technologies are already figuring in the political debate and hover in the background of diplomatic discussions, since it will be impossible to limit future warming to 2 degrees C, as G-8 leaders pledged in July, without something like a new technology to suck carbon dioxide from the atmosphere. It is easy to forget that these are proposals, not proven technologies. There is no assurance that any will actually work as imagined.

Source: by Dianne Dumanoski www.e360.yale.edu