by Ben Courtice
As many who follow the science news would realise, there is a large current of opinion that the amount of greenhouse gases in the atmosphere is already too high and poses an unacceptable risk of runaway climate change. Given that greenhouse gases typically take 20 years after emission to have their effect on climate, we would be best off if we could reduce the amount of these gases before their effects manifest.
Much government and industry spin has surrounded the hypothetical technology for geosequestration of gases by liquefying them and pumping them under layers of rock deep beneath the earth. However, a much easier, proven technique called variously "biochar", "agrichar" or "terra preta" has gained some attention. Greens and lefts ought to pay special attention to biochar.
Climate change is a complex problem with many facets. In the words of Barry Commoner, "It is also important to keep in mind the several aims of the transformation in production technologies, for improperly satisfying one of them may ricochet into another problem area" and "If these goals are approached piecemeal, there is a danger that the method used to reach one of them will interfere with the others".
Biochar has the promise of being (part of) a solution to greenhouse gases that helps to solve other attendant problems, rather than increasing them. Essentially, the technique involves turning left-over crop residue (stalks etc) into charcoal and ploughing this into the earth, where it is found to increase the soil's retention of nutrients and water, and to promote the growth of beneficial micro-organisms. As well as benefiting agriculture, charcoal is a stable form of carbon and may last in the soil for thousands of years. Thus it is possible, as part of a shift to organic farming practices, to use biochar to turn agriculture from a net emitter of carbon to a tool for drawing carbon back out of the atmosphere.
The International Agrichar Initiative (now the International Biochar Initiative) held a conference on April 30 - May 2 2007 in New South Wales, Australia. Kelpie Wilson wrote on May 3 at www.truthout.org, "As delegates met in Bangkok this week to debate climate change solutions contained in the IPCC's latest report, one technology not mentioned in the draft report was being closely examined at a conference in Australia in the beach town of Terrigal, just north of Sydney. The first meeting of the International Agrichar Initiative convened about 100 scientists, policymakers, farmers and investors with the goal of birthing an entire new industry to produce a biofuel that goes beyond carbon neutral and is actually carbon negative. The industry could provide a "wedge" of carbon reduction amounting to a minimum of ten percent of world emissions and possibly much more. " The conference was also covered by the ABC's Catalyst program.
It's not just carbon emissions that are affected. According to Wilson, "Nitrous oxide is 270 times more potent than CO2 as a greenhouse gas and it lasts for 150 years in the atmosphere. Use of nitrogen fertilizers is a major source of the gas, and a difficult one to mitigate. But agrichar applied to fields seems to have a significant damping effect on nitrous oxide emissions. Lukas Van Zwieten, a researcher at the New South Wales Department of Primary Industries, looking at preliminary results of his field trials measuring nitrous oxide emissions from agrichar amended soils, said "the more I look into this, the more excited I get." "
The obvious potential of biochar to be used as a carbon credit or offset in carbon trading schemes will probably help to profile the technology. At least it is a more stable form of sequestration than simply planting trees, one of the best known greenwashing offset schemes.
More importantly, biochar production and use is easily adopted by small poor farmers in third world countries. The main cost is a kiln for pyrolisis of the wood or crop residue. This could conceivable be combined with cooking or other domestic needs. To quote again from Wilson, "About half the world's population relies on charcoal for cooking fuel, and the production of charcoal drives deforestation in Africa and other places... An effort to replace these [inefficient] kilns with modern, efficient pyrolysis units would relieve the pressure on forests by reducing waste and adding the ability to use any source of biomass, including agricultural waste products such as rice hulls. The ultimate objective is to produce enough charcoal to have some left over to bury and increase soil fertility, leading to a bootstrapping effect where increased yields provide both more food and more biomass for energy."
As many who follow the science news would realise, there is a large current of opinion that the amount of greenhouse gases in the atmosphere is already too high and poses an unacceptable risk of runaway climate change. Given that greenhouse gases typically take 20 years after emission to have their effect on climate, we would be best off if we could reduce the amount of these gases before their effects manifest.
Much government and industry spin has surrounded the hypothetical technology for geosequestration of gases by liquefying them and pumping them under layers of rock deep beneath the earth. However, a much easier, proven technique called variously "biochar", "agrichar" or "terra preta" has gained some attention. Greens and lefts ought to pay special attention to biochar.
Climate change is a complex problem with many facets. In the words of Barry Commoner, "It is also important to keep in mind the several aims of the transformation in production technologies, for improperly satisfying one of them may ricochet into another problem area" and "If these goals are approached piecemeal, there is a danger that the method used to reach one of them will interfere with the others".
Biochar has the promise of being (part of) a solution to greenhouse gases that helps to solve other attendant problems, rather than increasing them. Essentially, the technique involves turning left-over crop residue (stalks etc) into charcoal and ploughing this into the earth, where it is found to increase the soil's retention of nutrients and water, and to promote the growth of beneficial micro-organisms. As well as benefiting agriculture, charcoal is a stable form of carbon and may last in the soil for thousands of years. Thus it is possible, as part of a shift to organic farming practices, to use biochar to turn agriculture from a net emitter of carbon to a tool for drawing carbon back out of the atmosphere.
The International Agrichar Initiative (now the International Biochar Initiative) held a conference on April 30 - May 2 2007 in New South Wales, Australia. Kelpie Wilson wrote on May 3 at www.truthout.org, "As delegates met in Bangkok this week to debate climate change solutions contained in the IPCC's latest report, one technology not mentioned in the draft report was being closely examined at a conference in Australia in the beach town of Terrigal, just north of Sydney. The first meeting of the International Agrichar Initiative convened about 100 scientists, policymakers, farmers and investors with the goal of birthing an entire new industry to produce a biofuel that goes beyond carbon neutral and is actually carbon negative. The industry could provide a "wedge" of carbon reduction amounting to a minimum of ten percent of world emissions and possibly much more. " The conference was also covered by the ABC's Catalyst program.
It's not just carbon emissions that are affected. According to Wilson, "Nitrous oxide is 270 times more potent than CO2 as a greenhouse gas and it lasts for 150 years in the atmosphere. Use of nitrogen fertilizers is a major source of the gas, and a difficult one to mitigate. But agrichar applied to fields seems to have a significant damping effect on nitrous oxide emissions. Lukas Van Zwieten, a researcher at the New South Wales Department of Primary Industries, looking at preliminary results of his field trials measuring nitrous oxide emissions from agrichar amended soils, said "the more I look into this, the more excited I get." "
The obvious potential of biochar to be used as a carbon credit or offset in carbon trading schemes will probably help to profile the technology. At least it is a more stable form of sequestration than simply planting trees, one of the best known greenwashing offset schemes.
More importantly, biochar production and use is easily adopted by small poor farmers in third world countries. The main cost is a kiln for pyrolisis of the wood or crop residue. This could conceivable be combined with cooking or other domestic needs. To quote again from Wilson, "About half the world's population relies on charcoal for cooking fuel, and the production of charcoal drives deforestation in Africa and other places... An effort to replace these [inefficient] kilns with modern, efficient pyrolysis units would relieve the pressure on forests by reducing waste and adding the ability to use any source of biomass, including agricultural waste products such as rice hulls. The ultimate objective is to produce enough charcoal to have some left over to bury and increase soil fertility, leading to a bootstrapping effect where increased yields provide both more food and more biomass for energy."
- More on Biochar on LeftClick:Permanent drought or Zero Emissions and drawdown of existing carbon
- More bog discussions on Biochar
