Extreme outcomes from fossil fuels burning are probably easily avoidable at low cost.. Ocean iron fertilization would cool the Earth by increasing natural sulfur aerosal production which would increase cloud formation and planetary reflectivity.
July 24, 2007 -- Prof. Oliver Wingenter of New Mexico Tech and his colleagues propose a limited iron fertilization of the Southern Ocean as a means to stimulate the natural sulfur cycle associated with marine phytoplankton which could result in increased cloud reflectivity that would slow down global warming and possibly decrease sea level rise.
Wingenter and his research colleagues Dr. Scott M. Elliot at Los Alamos National Laboratory and Prof. Donald R. Blake at University of California, Irvine report their research findings in an article published online July 18 in the journal Atmospheric Environment, titled "New Directions: Enhancing the natural sulfur cycle to slow global warming,".
The scientists base their plan on their observations made during the Southern Ocean Iron Experiments (SOFeX) research expedition, the longest and most comprehensive ocean iron fertilization experiment to date, which was carried out in 2002 aboard three research ships in the Southern Ocean, between New Zealand and Antarctica.
The scientists who conducted the SOFeX experiment were looking for a cheap way to cool the planet by pulling carbon dioxide out of the atmosphere. Instead they found a cheap way to pump a planet-cooling sulfide into the atmosphere.
Wingenter thinks we could delay global warming by 10 to 20 years at very low cost with iron fertilization of only 2% of the Southern Ocean. With just 30 ships and at most $100 million per year we could delay warming by 10 to 20 years.
"However, marine microorganisms not only consume inorganic carbon, but also produce and consume many climate-relevant organic gases," Wingenter continues. "The greatest climate effect of iron fertilization may be in enhancing dimethyl sulfide (DMS) production, leading to changes in the optical properties of the atmosphere and cooling of the region." Samples taken by Wingenter during SOFeX showed that the concentration of DMS increased about five times in the iron fertilized patch versus outside. Emissions of DMS are the main source of sulfate particle formation to the region and "seed" much of the cloud formation.
Wingenter and his research colleagues propose a limited fertilization of only about 2 percent of Southern Ocean---which would result in an estimated two degrees (Celsius) cooling of the region. A program of limited-scale iron fertilization in the Southern Ocean and perhaps a portion of the equatorial Pacific may have the potential to set back the tipping point of global warming from about 10 years to about 20 or more years," Wingenter estimates.
An iron-fertilization program of the scale envisioned by Wingenter and his fellow researchers would require about 30 ships, fertilizing the Southern Ocean with about 22 kilotons of iron sulfate, at an annual cost of anywhere between $10 million and $100 million, according to the article in Atmospheric Environment.
A program like this one could get tested at smaller scales and then scaled up very quickly as necessary. UC Irvine physicist Gregory Benford has proposed another cheap way to cool the planet as well. Cooling the planet down seems relatively easy. But I've yet to come across proposed engineering solutions for another consequence of atmospheric CO2 build-up: acidification of the oceans as atmospheric carbon dioxide dissolves into the oceans. What to do about that other than reduce CO2 emissions or accelerate the extraction of carbon from the atmosphere?
Writing in the Spring 2007 edition of the Wilson Quarterly scholar James R. Fleming argues that would-be climate engineers lack the ability to model all the side effects of climate engineering.
Yet thanks to remarkable advances in science and technology, from satellite sensors to enormously sophisticated global climate models, the fantasies of the weather and climate engineers have only grown. Now it is possible to tinker with scenarios in computer climate models—manipulating the solar inputs, for example, to demonstrate that artificially increased solar reflectivity will generate a cooling trend in the model.
But this is a far cry from conducting a practical global field experiment or operational program with proper data collection and analysis; full accounting for possible liabilities, unintended consequences, and litigation; and the necessary international support and approval. Lowell Wood blithely declares that if his proposal to turn the polar icecap into a planetary air conditioner were implemented and didn’t work, the process could be halted after a few years. He doesn’t mention what harm such a failure could cause in the meantime.
There are signs among the geoengineers of an overconfidence in technology as a solution of first resort. Many appear to possess a too-literal belief in progress that produces an anything-is-possible mentality, abetted by a basic misunderstanding of the nature of today’s climate models. The global climate system is a “massive, staggering beast,” as oceanographer Wallace Broecker describes it, with no simple set of controlling parameters. We are more than a long way from understanding how it works, much less the precise prediction and practical “control” of global climate.
Fleming also wonders who should control a climate engineering effort. The effects of climate engineering would create large numbers of both winners and losers. Cooling via engineering efforts would improve farming in some regions and make it much harder in other regions. Cooling would change costs of heating and air conditioning and air conditioning and change which structure designs are ideal in many areas.
Assume, for just a moment, that climate control were technically possible. Who would be given the authority to manage it? Who would have the wisdom to dispense drought, severe winters, or the effects of storms to some so that the rest of the planet could prosper? At what cost, economically, aesthetically, and in our moral relationship to nature, would we manipulate the climate?
But these questions which Fleming raises can already be raised about existing human activity. We build cities and cities cause severe thunderstorms. We plow fields on a massive scale to grow crops and farms reduce cloud cover and rainfall. In fact, humans might already have engineered the planet's climate thousands of years ago via farming and forest destruction that might have prevented an ice age. The difference with the modern would-be climate engineers isn't necessarily the scale on which they want to act. Rather, they want to intervene on purpose in a system to partially cancel out the effects of interventions we've already done by accident.
Given that our current industries, technologies, and lifestyles already generate lots of side effects and external costs (and not just due to climate effects) I do not see why we should oppose climate engineering just because it will inflict costs on some. If we took that approach on all environmental questions we'd have to abandon modern technology and force a huge contraction in the size of the human population. In many cases those costs will effectively come from returning a local environment to a state more like it would be absent human intervention. Though that would not always be the case.
Update: Climate cooling measures such as Gregory Benford and Oliver Wingenter propose can be implemented so quickly that we can wait to see whether global warming becomes a big problem before trying these methods. But it would be helpful to do research on these proposals to measure their effects and get a better handle on what undesirable side effects would arise from their use.
The best response I can see to rising CO2 levels is to try harder to develop cheaper substitutes to fossil fuels. Research that produces energy that is both cheaper and cleaner would give us the best of both worlds.
|Share |||Randall Parker, 2007 September 01 03:25 PM Climate Engineering|