Friday, December 5, 2014

Newsweek cover - Planet Reboot: Fighting Climate Change With Geoengineering

Planet Reboot: Fighting Climate Change With Geoengineering

Walking the Plankton

The world’s oceans have countless tiny organisms called phytoplankton. Also known as microalgae, these itty-bitty plants eat carbon dioxide from the water and release oxygen into the ocean as a by-product. Once the phytoplankton blooms take up the carbon from the ocean’s surface, they sink down to the deep ocean, where the carbon is effectively sequestered. They’re so productive that scientists think phytoplankton produce about 50 percent of the oxygen humans breathe.
If we could get phytoplankton to boost their uptake of carbon, it could have a huge global impact—and would be very simple to do. When the tiny plants get a boost of nutrients from the water around them, they eat a lot more carbon. And right now the oceans of the world are low in one particular nutrient—iron—although scientists aren’t sure why. So the phytoplankton aren’t nearly as active as they could be. In fact, when big storms blow iron-rich dust into the oceans, satellites see evidence of phytoplankton blooms in areas where they normally aren’t visible.
Over the past decade there have been more than 12 small-scale experiments in which scientists (and one rogue California businessman named Russ George) dumped iron dust into the ocean to test the hypothesis that phytoplankton could be triggered to wake up and start devouring mass quantities of carbon. All of the experiments (except George’s) showed that there was some benefit to seeding the ocean with iron.
Victor Smetacek, a biological oceanographer at Germany’s Alfred Wegener Institute for Polar and Marine Research, contributed to one such study in 2009. Though he says there needs to be a lot more research into ocean seeding, he believes it’s a very promising option. “I’m talking about using a natural mechanism that has already proven itself,” Smetacek says. “We need to harness the biosphere and see where we can apply levers to lift the carpet and sweep some of the carbon under.”

Oddly, however, the ocean-seeding option seems to be a controversial one. Smetacek says that although he believes strongly in its benefits, it has never been a popular option among climate scientists. “This ocean iron fertilization is highly unpopular with technocratic geoengineers because it involves biology. But we have to get the biosphere to help,” he says. “The only thing we can do is try and nudge the biosphere as much as possible and try to open up as many carbon sinks as possible.”

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