V i v i a n  S o n g
Freelance writer
Freelance writer
Reflecting on the weather

Published in the Toronto Sun and Sun Media papers January, 2008.

The human imagination is both a remarkable and frightening thing.

Long before carbon dioxide and climate change dominated headlines, visionary scientists have been dreaming up ways to artificially manipulate the global environment through large-scale engineering feats of the most ambitious kind.

It's called geoengineering and explores futuristic ideas such as the positioning of space-based mirrors between the Earth and the sun to reflect the sun's rays and help cool the earth, not unlike a gargantuan pair of sunglasses for the planet.

It's also what made rainmakers out of scientists after the World War II, once it was discovered they could make it rain by dumping silver iodide and dry ice from planes to induce cloud formation.

While geoengineering had long been dismissed as fringe science -- dangerous and irresponsible tampering of Mother Nature -- the tide has turned recently along with the growing skepticism that the world will be able to cut emissions in time, said the University of Calgary's David Keith, who holds the Canada Research Chair in Energy and the Environment.

"What's changed in the last year is that now, a bunch of reasonably serious and respected people in atmospheric science and the political world are saying we need to pay attention to this," he said.

But the notion of interfering with natural cycles using man-made technology is not without its ethical, political and scientific controversies.

In theory, launching sun shades into space to deflect sunlight from the planet makes sense. In 1992, the National Academy of Sciences published a report positing that 55,000 mirrored sails would increase the Earth's albedo, or surface reflectivity, by 0.5% and cancel out the doubling effect of CO2.

It's also one of the "cleaner" albedo modification schemes, Keith writes in an article published in 2000 by the Oxford University Press.

If the solar sails were steerable, their effect could be switched off at will and could also be used to redirect radiation at specific areas of the Earth as a form of weather control.

One scientist has been putting flesh to the idea after recently winning a NASA Institute for Advanced Concepts grant, attributing costs and measurements to what was once considered a flight of fancy.

In a 2006 report published in the Proceedings of the National Academy of Sciences, astronomer Roger Angel detailed plans of launching trillions of small lenses -- each about 60 cm wide and as light as a butterfly -- above Earth into an orbit aligned with the sun, called the Lagrange point, or L1 orbit.

Despite their research, Keith and Angel stress geoengineering solutions should be viewed as emergency strategies only, akin to exit plans in the event of a house fire, Keith said.

"I don't think anyone who is responsible is advocating we do geoengineering right now," he said. "What I think many people, including me, are advocating is that at this point, we have to do the research. Geoengineering has been so politically incorrect and now we're in a dangerous position where there's a lot of hype in the blogosphere but there's been very little quality research over the last decade."

Instead of addressing climate change at its source, critics charge that geoengineering schemes are nothing more than extravagant contraptions that would reduce the political will to reduce emissions.

Keith also points out the larger implications for solar shields in his report. They could be used as offensive weaponry. How would the project be governed? What would be the side effects? Could weather control lead to the geoengineering of the global environment to suit human needs?

"If we get this wrong, or overpromise what geoengineering can do, everybody loses," Keith said. "It's not something that can be done tomorrow but it's important that people talk about it seriously in order to make decisions. We will, whether we like it or not, be faced with the decision of whether or not to do this over the next few decades, especially if the climate problem is worse than we think."

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A SCIENCE FICTION SOLUTION?

·  The proposal: Deploy 16 trillion refracting discs, made of transparent film, into orbit between the Earth and the sun, to block about 2% of the sun's rays.

·  Their total mass would weigh 20 million tonnes and the lenses would be assembled before launch, to avoid the need for construction or unfolding in space.

·  Transporting the holding fliers into space would cost $4 trillion US alone at $50/kg, while production costs are still unclear, given the unprecedented scale of mass-production.

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1. Lenses would be launched into space, in batches of 800,000, by electromagnetic acceleration to escape the Earth's gravity, followed by ion propulsion.

2. One-tonne payload would disperse lenses, over a period of one year, into an orbit in alignment with the sun.

3. Eventually, trillions of lenses would orbit around the sun and deflect heat from Earth.

For the next few weeks, Green Planet will look at other geoengineering project like stratospheric aerosols, ocean fertilization, and mass forestation.



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