According to two highly respected environmental scientists, sending nutrient-rich water from the ocean's depths to the surface through vertical pipes could fertilize carbon dioxide-eating algae and help slow climate change.

James Lovelock, the author of Gaia, and Chris Rapley, director of the Science Museum in London, adhere to the belief that the 200-meter tubes would help offset our consumerist culture's carbon dioxide emissions. The two men wrote a letter to the journal Nature saying the Earth was becoming hotter much faster than we could limit our carbon emissions, suggesting that our small attempts at doing so have little impact.

A Santa Fe, New Mexico-based company, Atmocean, has created a similar, if not opposite, idea called "upwelling." The company is developing pipes (shown in photo) that would bring carbon dioxide down to the ocean's floor, which the University of Hawaii at Manoa plans to test next year. You can watch a video demonstrating Atmocean's technologies here.

But the folks at Greenpeace still think limiting our own emissions and changing the way we produce energy is the way to go, instead of turning to fancy geo-engineering.