Wednesday, September 2, 2009

Algae-coated buildings touted as climate fix

The future of green technology is algae-cultivating buildings, artificial trees, and lots of white roofs, according to the U.K.'s Institution of Mechanical Engineers. The group on Thursday released a report that recommends governments fund research on geoengineering, or large-scale fixes for climate change. The report, a year in the making, is targeted at policymakers and is meant to inspire engineers to develop ways to cut greenhouse gas concentrations in the atmosphere.

As concern grows over climate change, a number of geoengineering ideas have been proposed, including placing mirrors in space to reflect sunlight or shooting sulfur particles into the stratosphere, which would also have a cooling effect. However, in its analysis, the Institution of Mechanical Engineers found that most promising geoengineering techniques can be done on Earth. It argues that a handful of technologies be deployed at large scale, along with other strategies, to mitigate the effects of climate change.

At the top of the list are artificial trees, which are mechanical devices that can absorb carbon dioxide from the air faster than trees and then sequester that gas underground. The institution's report refers to the research done by Columbia University Professor Klaus Lackner, who is researching the concept and materials to absorb large amounts of CO2. Also required are underground storage formations, such as depleted oil wells. At a cost of $20,000 per tree, the institution concludes that it's the most practical approach.

Cultivating algae to make liquid fuel is one of the most active areas of research in biofuels. The institution recommends that algae be incorporated into buildings so algae can be grown at a large scale. Algae would grow from pumped-in carbon dioxide and sunlight and be harvested for use either as a liquid fuel to run in a combined heat-and-power unit or turned into biochar, or charcoal used as a soil conditioner that also sequesters carbon from the air.

Finally, the institution says that buildings should be retrofitted with reflective roofs to deflect the sun's rays. In the past months, U.S. Energy Secretary Steven Chu has publicly touted this relatively low-tech approach, which was studied in-depth at the Lawrence Livermore Laboratory last year. Although proposing billions of white roofs doesn't appear to be controversial, many other geoengineering ideas are. For example, scientists have warned about the environmental impact--or effectiveness--of "seeding" the ocean with iron to spur growth of plankton to sequester carbon.

In anticipation of a report on geoengineering from the U.K.'s Royal Society next week, watchdog ETC Group warned against unintended consequences from large-scale projects. "Even the most careful computer models won't be able to predict what will happen if an experiment is scaled-up and moved out of doors," the group said in a statement Friday.

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