Everyone knows that sea otters are adorable (just look at that picture). But now it turns out they can also play a huge role in pulling carbon-dioxide out of the air:

Sea otters could lock nearly 10 million tons of carbon from the Earth’s oceans, if their population was restored to healthy, pre-hunting levels, according to an American scientist.

Chris Wilmers, at the University of California, Santa Cruz, and colleagues determined that the endangered animal, feasting on sea urchins, helped the growth of kelp forests, which can sequester at least 0.18 kg of carbon from the atmosphere for every square metre of otter occupied coastal waters.

As it happens, The Wall Street Journal just reviewed a book about how the sea-otter trade helped drive America's westward expansion from the 1600s on. "With as many as one million hairs per square inch," we learn, "sea otter fur is densest of all mammals', and the most luxurious to the touch." Everyone wanted a piece of the action—North America settlers, the Chinese, Russians, Japanese… But the fur craze took a huge toll on the otter populations, which in some areas are seriously endangered—there are just 70,000 in Alaska today. So urchins are running wild and kelp forests are dwindling. Bad news.

By the way, this story underscores the usefulness (and flexibility) of a carbon-trading approach to fighting global warming. Let's say Congress enacted a cap-and-trade system and pollution permits were selling for about $20 a ton. If Wilmers is right and a healthy sea otter population could sequester ten million tons of carbon, that'd be worth $200 million. So polluters might decide that it's cheaper to fund sea otter preservation programs than cut power use (at least in the short term), and new offset projects could get approved. Voila: There's suddenly money to try this sea otter strategy. (Obviously you'd need to have regulators make sure these offset projects are actually working.)

On the other hand, if your national energy policy just consists of a bunch of flat regulations and subsidies for different energy sources, then this whole sea otter business is going to get ignored. Sure, maybe Congress will decide that sea otter preservation is something worth funding directly, but waiting for the legislature to bankroll worthwhile carbon-reduction projects is an awfully sluggish and inflexible way to do business. (Plus, who knows, maybe the urchin lobby steps into the fray.) Right now, Congress is leaning toward this regulation-and-subsidy approach to energy. But there's an excellent case for a more flexible market-based system. Just ask the otters.

(Flickr photo credit: mikebaird)