August 27, 2009

Geo-Engineering Could Help Fight Climate Change

Giant "synthetic trees" that reflect heat back into the sky may become a common sight within the next 20 years, as the Institution of Mechanical Engineers sets out to combat the world's climate change with cutting edge technology.

Engineers are working on producing 100,000 artificial trees as part of three practical geo-engineering ideas listed in a new report.
Without geo-engineering, dangerous climate change will be unavoidable, said the authors of the report.

A 100-year roadmap to "decarbonize" the world was also laid out in the report.

Lead author of the report Dr. Tim Fox told BBC News that one should not see geo-engineering as a "silver bullet" that could single handedly fight climate change, but should rather be combined with other efforts to cut back on carbon emissions and adapt to the effects of climate change.

There are many climate scientists who have calculated that the world has a small window of only a few decades to reduce emissions before there is so much carbon dioxide in the atmosphere that dangerous hikes in global temperature cannot be avoided. 

The authors of this report say that geo-engineering of the type they propose should be used on a short-term basis to buy the world time, but in the long term it is vital to reduce emissions.

Nem Vaughan of University of East Anglia listed two different types of geo-engineering.

"The first category attempts to cool the planet by reflecting some of the sunlight away. The problem with this is that it just masks the problem...the other type of geo-engineering is to remove carbon dioxide from the atmosphere and store it."

Hundreds of different options were examined by the team, but only three were found to be practical and feasible with current technology to make the cut.

The main deciding factor of choosing the three was that they should be a low-carbon option rather than just adding to the problem.

"Artificial trees are already at the prototype stage and are very advanced in their design in terms of their automation and in the components that would be used," Dr. Fox told BBC News.

"They could, within a relatively short duration, be moved forward into mass production and deployment," he added. 

The trees would be designed to capture carbon dioxide from the air, through a filter.
Then, the CO2 would be removed from the filter and stored, which would call for the development of a technology in conjunction with carbon storage infrastructure.

According to Dr. Fox, the size of the prototype artificial tree is comparable to the size of a shipping container and could remove thousands of times more carbon dioxide from the atmosphere than a real tree of the same size. 

One of the other two ideas the team came up with was to capture carbon by installing what they call "algae based photobioreactors" onto buildings. They would be transparent containers holding algae, which would then remove carbon dioxide from the air during photosynthesis.

The third option honed in on cutting back on solar radiation as it comes in by reflecting sunlight back into space. This could be achieved most practically by having reflective roofs on buildings, the report says.

The authors emphasize that all of the option require more research, and that they have called on the UK government to invest over $16 million to analyze the effectiveness, risks and costs of such an endeavor.

"We very much believe that the practical geo-engineering that we are proposing should be implemented and could be very much part of our landscape within the next 10 to 20 years," said Dr. Fox.


On the Net: