Researchers ask how best to engineer the planet

October 31, 2009 6:00 AM PDT
by Martin LaMonica

CAMBRIDGE, Mass.--A group of academics on Friday considered the ultimate engineering challenge: building machines to stabilize the earth's climate.

The Massachusetts Institute of Technology convened a symposium here to discuss the potential benefits and pitfalls of geoengineering, also called climate engineering. Everything from shooting light-blocking particles into the atmosphere to "artificial trees" is being seriously studied, despite trepidation among researchers and opposition from others.

During talks Friday morning, academics said climate engineering techniques are not well understood and, because of the complexity of the global climate system, individual approaches are pockmarked with uncertainties.

...(snip)...the symposium...was called Engineering a Cooler Planet.

Speakers said each climate engineering approach needs to be viewed with an associated cost and risk. For example, one relatively inexpensive idea is to shoot particles, called aerosols, into the air in order to block the amount of heat from the sun that reaches the earth's surface.

The cooling effect from aerosols, such as sulfur dioxide, in the atmosphere is rapid--measured in days or years. But they also impact the planet's water cycle. Early models show that large-scale efforts to inject aerosols in the atmosphere would likely make certain areas drier and affect the monsoons in India and Asia, said Joyce Penner, a professor of atmosopheric sciences at the University of Michigan.

...(snip)...

There are two general approaches to engineering for a cooler planet: reflecting sunlight back into space or removing carbon dioxide from the air and storing it.

Injecting sulfur-based aerosols in the atmosphere have a known cooling effect observed in volcanic eruptions, including Mount Pinatubo in 1991. The approach is more practical than, say, placing mirrors in space. But there still isn't suitable understanding of how the entire climate system would react, including potential changes to ocean circulation, ocean ecosystems, and land precipitation, said Penner.

Also, blocking sunlight from space does not address the problems caused by higher concentrations of carbon dioxide on earth, notably ocean acidification which makes it more difficult for marine animals with shells or corals to grow, speakers noted.

Other approaches for reflecting heat back into space include spraying sea salt from special-purpose boats to enhance the reflectivity of clouds or installing white roofs on buildings to bounce more sunlight back into space.

Land-based approaches to reducing greenhouse gas concentrations include growing algae-based fuels at massive scale, storing carbon dioxide in underground geological formations, and making charcoal with plants to create a soil amendment called biochar.

There have also been 12 tests to stimulate plankton growth by "fertilizing" the ocean with iron. The goal is to create a rapid "plankton bloom" which will remove carbon dioxide and sequester it in the ocean. But this technique is difficult to verify and risks transforming the existing ocean ecosystems, said Tim Lenton, professor of earth system science at the University of East Anglia.

...(snip)...

The symposium at MIT is not the first meeting of scientists to consider geoengineering--the idea has been discussed for decades. But some of the academics on Friday said the current trajectory of climate change argues in favor of at least doing research on climate engineering techniques, even if these projects are ultimately never launched.

...(snip)...


http://news.cnet.com/8301-11128_3-10387 ... 7-1_3-0-20

There are some things on this Planet that should just not be fooled with and IMHO Mother Nature is one of those things, this can only lead to something very bad