Giant ocean tubes proposed as global warming fix

From a story by Kate Ravilious for National Geographic News:

Imagine an ocean full of giant pipes that pump up cold, nutrient-rich water from deep below, encouraging surface algae to bloom and suck carbon dioxide from the atmosphere.

That's the controversial new vision of James Lovelock, the independent British scientist best known for proposing the Gaia hypothesis, and Chris Rapley, a space physicist and director of London's Science Museum.

The pair claims that such climate engineering solutions may be the only way to hold global warming at bay given its current progress. (See a global warming interactive.)

"Global warming appears to be an irreversible process, and if we don't do anything then the world will just heat up to a stable, hot state," Lovelock said. "The stakes are now so high that we have to act."

But other experts are skeptical, pointing out that the scheme could release more carbon than it absorbs while putting fragile marine life in danger.