To avoid climate catastrophe, we’ll need to remove CO2 from the air. Here’s how.

Jay OwenSustainability News

 

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With sufficient investment and strategic deployment, carbon dioxide removal and storage can play a key role in keeping global warming to a level we can live with. Read more…

 

… Reports periodically appear pointing out that one approach or another is not going to cut it: Trees can store carbon, but they compete with agriculture for land, soil can’t store enough, machines like the ones Lackner envisions take too much energy, we don’t have the engineering figured out for underground storage.

It’s likely true that no one solution is the fix, all have pros and cons, and many have bugs to work out before they’re ready for prime time. But in the right combination, and with some serious research and development, they could make a big difference. And, as an international team of climate scientists recently pointed out, the sooner the better, because the task of reducing greenhouse gases will only become larger and more daunting the longer we delay…

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Afforestation and Reforestation

Pay your entrance fee, drive up a winding road through Sequoia National Park in California, hike half a mile through the woods, and you’ll find yourself at the feet of General Sherman, the world’s largest tree. With some 52,500 cubic feet (1,487 cubic meters) of wood in its trunk, the behemoth has more than 1,400 metric tons (1,500 tons) of CO2 trapped in its trunk alone.

Though its size is clearly exceptional, the General gives an idea of trees’ potential to suck CO2 from the air and store it in wood, bark, leaf and root. In fact, the Intergovernmental Panel on Climate Change estimates that a single hectare (2.5 acres) of forest can take up somewhere between 1.5 and 30 metric tons (1.6 and 33 tons) of CO2 per year, depending on the kinds of trees, how old they are, the climate and so on.

Worldwide forests currently sequester on the order of 2 Gt CO2 per year. Concerted efforts to plant trees in new places (afforest) and replant deforested acreage (reforest) could increase this by a gigaton or more, depending on species, growth patterns, economics, politics and other variables. Forest management practices emphasizing carbon storage and genetic modification of trees and other forest plants to improve their ability to take up and store carbon could push these numbers higher…

Carbon Farming

… Soil’s carbon-storing capacity could go even higher if research initiatives by the Advanced Research Projects Agency–Energy, a U.S. government agency that provides research support for innovative energy technologies, and others aimed at improving crops’ capacity to transfer carbon to the soil are successful. And, points out Eric Toensmeier, author of The Carbon Farming Solution, the capacity of farmland to store carbon can be dramatically increased by including trees in the equation as well.

“Generally it is practices that incorporate trees that have the most carbon [storage] — often two to 10 times more carbon per hectare, which is a pretty big deal,” Toensmeier says…