Lovelock: Adapt, try to survive, CO2 drawdown via biochar may help

Climate change is inevitable, proceeding and even accelerating

by Tyler Hamilton, June 22, 2009

Climate change is inevitable, proceeding and even accelerating.

With those alarming words, author and theorist James Lovelock left the two dozen or so people within earshot – a mixed bag of politicians, activists, corporate types and media – feeling awkwardly helpless. They'd gathered May 26, 2009, in a small boardroom on Spadina Ave. to hear the British scientist talk about the coming impacts of climate change.

Lovelock kept his message simple: There's nothing we can do now but adapt and survive. He even confided that he wanted the subtitle of his latest book, The Vanishing Face of Gaia: A Final Warning, to read "Enjoy It While It Lasts."

His publisher, perhaps figuring that hopeful people are more likely to purchase books, objected.

All this defeatist talk didn't sit well with most in the room, including Ontario Green Party leader Frank DeJong, who directly challenged Lovelock on his assertion. Surely, said DeJong, there's something we can do. "I just can't accept what you're saying."

When pushed, Lovelock said the only way we could do something meaningful was to extract and permanently store greenhouse gases from the atmosphere, in addition to dramatically reducing our emissions. If we stopped burning fossil fuels tomorrow, he explained, it wouldn't do much. The damage is done. We've already released enough carbon over the past 100 years to push us past the point of no return.

But if we could also extract CO2 we "might" have a shot. And the approach with the most potential, said Lovelock, is to turn organic material into "biochar" and bury it. Lovelock endorsed the approach during his May 26 meeting in Toronto. "I've written before about biochar, or agrichar, or charcoal, or just plain char – it's all pretty much the same. Take biomass, such as wood or municipal organic waste, and bake it at over 300 degrees C in the absence of oxygen. The process is called pyrolysis, and what it does is lock in about 60 per cent of the carbon in the charred biomass."

The char, unlike the original biomass, can't rot and release methane into the atmosphere. It doesn't oxidize. It is chemically stable for hundreds of years, meaning the carbon is permanently sequestered. "This makes it safe to bury in the soil or in the ocean," wrote Lovelock.

It is considered a way to extract CO2 from the atmosphere because while the char doesn't release CO2, the new trees, crops and algae that grow to replace the charred biomass consume CO2. Repeat the char-and-grow process repeatedly and on a large enough scale and you've essentially created a global carbon vacuum.

Lovelock isn't alone in his enthusiasm for charcoal sequestration, to the dismay of hyper-skeptical Guardian News columnist George Monbiot, who trashed the idea in a March column. Australian biologist Tim Flannery, author of the bestselling climate-change book The Weather Makers, is an avid supporter of the approach. James Hansen, head of the NASA Goddard Institute for Space Studies and a professor of Earth sciences at Columbia University, also sees an important role for turning biomass into charcoal as long as it's done responsibly.

Of course, it's not a silver bullet – there are no silver bullets with climate change. But if we're serious about halting and eventually lowering CO2 concentration in the atmosphere, it could prove the best way of managing organic waste from municipalities, croplands, wastewater treatment plants, and a certain amount of residues from forests.

Potentially, though more controversial, fast-growing poplar and willow trees that are planted once and can be harvested for about 20 years could become a source of biomass for char. These trees can be genetically modified to withstand heat and drought, as well as grow on depleted lands that can't be used for much – certainly not for growing food.

The problem, as with all other climate-mitigation approaches, comes with reaching scale. Can this really be done on a large enough scale to make a measurable impact? Nobody can say for sure, but Subodh Gupta, a chemical engineer at natural-gas giant EnCana Corp., says a good place to start is to turn municipal solid waste into charcoal.

Gupta presented a paper on the idea last Tuesday at the Canadian International Petroleum Conference in Calgary, calling it a "powerful concept" with "very significant potential."

Municipal solid waste makes sense for a number of reasons, he said. Thousands of municipalities across the continent have existing collection systems in place. The waste is not just free, but you get paid to take it. Also, there's no risk of running out.

His idea is to use a pyrolysis process to turn the organics (and potentially even plastics) into charcoal. The biogases released from the pyrolysis can be captured and used as fuel to run the process, eliminating the need for an external energy source.

The resulting charcoal is quite brittle and can be crushed or steamrolled to reduce its volume. It can then be safely stored in a landfill or even in bodies of water, where it will sit stable for hundreds of years without risk of rotting. It can even be scattered on topsoil to enhance nutrients of depleted lands.

In Gupta's view, this kind of charcoal sequestration is more practical and less expensive than the approach most pursued by the petroleum industry, which is the capture and underground storage of CO2 emissions from coal plants and other industrial facilities. He estimates that charcoal sequestration of municipal solid waste costs about $42 for every tonne of avoided CO2, compared to estimates as high as $150 a tonne for carbon capture and storage.

Link to article: http://www.thestar.com/sciencetech/article/654444