Biochar threatens biodiversity and soil biology?
Friday, May 22, 2009
Could it be that biochar doesn’t need scientists, it needs market economists and management accountants? Why are we questioning biochar? Because it threatens to distract government and industry attention from the soil carbon solution.
Ross Garnaut lambasted Australian business leaders for not making the effort to understand the issues behind climate change and the CPRS. He could have included anyone who eulogises biochar as the miracle solution to biosequestration and soil fertilty. Hip Hooray for Stephen Joseph and his wonderful team to be given $1.5 million for research. It canÂ´t be the only research being done on it. We suspect it is a drop in the ocean. Stephen’s response to the announcement is revealing: He preferred to have the money put towards building a pyrolisis burner that can produce 10,000 tonnes: “There is not a facility in Australia that the research community has access to.” Why not? How expensive are they? What will be the cost of biochar once it is up and running? Could it be that biochar doesn’t need scientists, it needs market economists and management accountants?
Why are we questioning biochar? Because it threatens to distract government and industry attention from the soil carbon solution. Lumping soil carbon in with biochar is misleading. They are not brothers or even cousins. Biochar is primarily a manufacturing process producing fuel, energy and soil ameliorants. A side effect of the manufacturing process is hte conversion of vegetation into char – a stable form of carbon. Its stability is similar to that of humus. But it cannot be compared. Because in the next 10-15 years agricultural soil management can produce hundreds of millions of tonnes of humus and biochar will struggle to produce one million in that time. The relative performance as a process for reducing the “Legacy Load” can be see in the conclusion of 20 IPCC soil scientists in the Royal Society’s Journal which decided that the world’s soils can extract 5-6 billion tonnes of CO2e per year.
There is another reason we want to draw attention to biochar’s limitations: it could have a negative impact on biodiversity and soil biology. This morning we had an enquiry from our CMA. A local farmer wants to put the dead and fallen timber on his property through a pyrolisis burner, creating char and offsets for the nearby cement manufacturer to buy. He mentioned that he had heard about biochar and the idea of using ‘waste’ vegetation on his farm from Tim Flannery during his visit to the Central West last week. Tim did suggest this idea during his lunch time speech to the 150 farmers on a bus tour of ‘carbon cockys” But after his visit to Michael Inwood and Graham Ross’s properties, he heard many things about the importance of soil biology and the role fallen timber plays in providing living quarters to microbes and worms, et al. Tim described it as ‘waste’ because fallen timber is considered only as a source of methane as they decompose. In his latest book – Now Or Never – Tim arrives at accurate conclusions about soil carbon: Soil, he says, is “˜the fastest way of sequestering carbon”™. He has reached a clear understanding of the reason why soil is so important: The Legacy Load: “œStanding stock of greenhouse gas in the atmosphere is around 200 gigatonnes… The strongest prospect of very large draw-down of atmospheric carbon lies in changes to our global agriculture and forestry practices,” he says. He acknowledges capacity of the 4 billion hectares of rangeland. Increase the soil carbon in “˜world”™s dry rangelands by a mere 2 per cent”¦ we could pull down around 880 gigatonnes of carbon from the atmosphere.”
It would be a tragedy if Biochar caused a battle for biomass.
Posted by Michael Kiely