Heliophage


The biochar backlash
March 30, 2009, 11:07 am
Filed under: Farming, Geoengineering, Interventions in the carbon/climate crisis

Interest in biochar has been building up in the UK recently. There was a cover story by Fiona Harvey in the FT a month ago with a familiar headline, Jim Lovelock and James Hansen have been extolling its virtues, it’s been on the Today Programme (text here on BBC News), there are new technologies being talked up and there’s an interesting looking workshop at the newly established UK Biochar Research Centre in Edinburgh on April 1st. And so of course there is also a backlash: last Monday George Monbiot, whose written on such subjects before,  delivered a stirring oppositional salvo in the Guardian (and here’s the link to the version on his own site, same text but with references — a good habit more newspaper columnists should take up):

This miracle solution has suckered people who ought to know better, including the earth systems scientist James Lovelock(3), the eminent climate scientist Jim Hansen(4), the author Chris Goodall and the climate campaigner Tim Flannery(5). At the UN climate negotiations beginning in Bonn on Sunday, several national governments will demand that biochar is eligible for carbon credits, providing the financial stimulus required to turn this into a global industry(6). Their proposal boils down to this: we must destroy the biosphere in order to save it.

In his otherwise excellent book, Ten Technologies to Save the Planet, Chris Goodall abandons his usual scepticism and proposes that we turn 200 million hectares of “forests, savannah and croplands” into biochar plantations. Thus we would increase carbon uptake, by grubbing up “wooded areas containing slow-growing trees” (that is, natural forest) and planting “faster-growing species”(7). This is environmentalism?

But that’s just the start of it. Carbonscape, a company which hopes to be among the first to commercialise the technique, talks of planting 930 million hectares(8). The energy lecturer Peter Read proposes new biomass plantations of trees and sugar covering 1.4 billion ha(9).

In their book Pulping the South, Ricardo Carrere and Larry Lohmann show what has happened in the 100m ha of industrial plantations planted around the world so far(16). Aside from trashing biodiversity, tree plantations have dried up river catchments, caused soil erosion when the land is ploughed for planting (which means the loss of soil carbon), exhausted nutrients and required so many pesticides that in some places the run-off has poisoned marine fisheries.

In Brazil and South Africa, tens of thousands of people have been thrown off their lands, often by violent means, to create plantations. In Thailand the military government that came to power in 1991 sought to expel five million people. Forty thousand families were dispossessed before the junta was overthrown. In many cases plantations cause a net loss of employment. Working conditions are brutal, often involving debt peonage and repeated exposure to pesticides.

As Almuth Ernsting and Rachel Smolker of Biofuelwatch point out, many of the claims made for biochar don’t stand up(17). In some cases charcoal in the soil improves plant growth; in others it suppresses it. Just burying carbon bears little relationship to the complex farming techniques of the Amazon Indians who created terras pretas. Nor is there any guarantee that most of the buried carbon will stay in the soil. In some cases charcoal stimulates bacterial growth, causing carbon emissions from soils to rise. As for reducing deforestation, a stove that burns only part of the fuel is likely to increase, not decrease, demand for wood. There are plenty of other ways of eliminating household smoke which don’t involve turning the world’s forests to cinders.

This kicked off a whole week of biochar stuff in the Guardian. Various people criticised came back to say that they were really talking only about making biochar from crop waste: here’s Jim Lovelock’s benevolent response and here’s a slightly pricklier one from Hansen and Kharecha. Chris Goodall also came back in a let’s find common ground sort of way, and there were letters pro and con. Peter Read’s right-to-reply piece, by way of contrast, comes out fighting.

This degraded land [a large amount of land discussed in Read’s biofuel plans] is former forest that has been logged over and abandoned – not, as Monbiot says, “land occupied by subsistence farmers, pastoralists, hunters and gatherers”. Given the chance, impoverished people often opt for a waged income. Does Monbiot wish to keep them impoverished for ever?

In reality there is not the shortage of land Monbiot implies but a desperate shortage of investment in the land. His “global total” of 1.36bn hectares of arable land does not include 2.38bn of unused potential arable land reported by the UN’s Food and Agriculture Organisation, into which such investment, eg irrigation, might go. Moreover, the productivity of the 1.36bn could be raised with biochar pyrolysed from currently wasted agricultural residues, thus linking carbon removal with increased food supply and incomes.

Monbiot misses the point that the need for land-use improvements comes from the threat of climatic catastrophe. With too much carbon in the atmosphere and oceans, some of it has to be removed and put somewhere safer. Using the gift of nature – photosynthesis which enables green plants to use the sun’s energy to absorb atmospheric carbon – is the only economic way.

The remedy is not “an easy way out” but needs hard work and good policy resulting in, to quote last year’s Sustainable Biofuels Consensus, “a landscape that provides food, fodder, fibre, and energy; that offers opportunities for rural development; that diversifies energy supply, restores ecosystems, protects biodiversity, and sequesters carbon.”

George comes back in kind:

I wasn’t harsh enough about Peter Read. In his response column today he uses the kind of development rhetoric that I thought had died out with the Indonesian transmigration programme.

To him, people and land appear to be as fungible as counters in a board game. He makes the extraordinary assertion that “degraded land” – which he wants to cover with plantations – is uninhabited by subsistence farmers, pastoralists or hunters and gatherers. That must be news to all the subsistence farmers, pastoralists and hunters and gatherers I’ve met in such places. Then he repeats the ancient canard that, by denying such people the opportunity to have their land turned into a eucalyptus plantation/hydroelectric dam/opencast mine/nuclear test site/re-education camp or whatever project the latest swivel-eyed ideologue is trying to promote, we are keeping them in poverty.

Has he learnt nothing from the past 40 years of development studies? Does he not understand that development is something that people must choose, not something that can be imposed on them from on high by megalomaniacs?

It should be fairly obvious to everyone who’s not just in this for the aggro that there will be good biochar interventions and bad ones. Forcing biochar on people or soils that don’t want it or can’t prosper with it will not help; helping people to find systems that are biochar friendly could quite possibly provide the win-win prospects everyone wants to see. As usual, Gary has sensible things to say about this, with helpful comparisons to the use of manure and lime as soil additives — as might be expected from someone whose ideas are rooted in practice and who has been blogging on this topic a lot while remaining impressively self-critical.

My biggest worry about the technology is that its strengths could have within them a fatal flaw. The soil is an easily reached reservoir, and provides a multiplier effect that’s crucial to the efficacy of biochar: the carbon stored in biochar schemes is not just the carbon in the charcoal, it’s the increased organic carbon in the rest of the soil. But easily reached is also easily breached, and multipliers can work two ways. If people use biochar to store a lot of carbon in soil, but not enough to forestall significant warming (which is a not unlikely scenario in the world biochar enthusiasts imagine) then they’ll have provided an extra bolus of soil carbon to be respired back into the atmosphere by the warmer, and thus harder working, soil bacteria; they will have effectively traded emissions now for emissions later. So the carbon could quickly come right back out. If the microbial priming effect kicks in in this scenario — with the easily mobilised carbon providing enough energy for the bacteria to tackle more refractory carbon they would normally ignore —  you might end up with not just with the carbon you stored away leaking out, but also some of the carbon that was already there. This is a subject on which I’d like to see more research before squirelling away the odd gigatonne of carbon.

Further resources: International Biochar Initiative, CSIRO biochar report (pdf), Biofuelwatch

Image borrowed from www.vividaria.it, rights neither asserted not inquired into, happy to remove if owners object


5 Comments so far
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Oliver makes the reasonable comment that if biochar is effective it may increase the total amount of organic carbon in the soil and that in warmer temperatures we can expect more respiration from bacterial and other activity.

On page 92 of the recently published Biochar for Environmental Management (ed Lehmann and Joseph) Thies and Rillig make the point that biochar amended soils have ‘higher microbial biomass and abundance of culturable bacteria and fungi, but significantly lower respiratory activity and, thus, a higher metabolic efficiency’.

Biochar soils also seem to have decreased nitrous oxide and methane emissions and greater water retention. These advantages should, I think, should make us particularly interested in biochar in a world of higher temperatures.

Comment by Chris Goodall

When will it occur to those concerned about carbon leaking from a biochar pool in soil that bio-available carbon (BAC) is respired from bacterial metabolic processes that digest infalling biomass waste from plamts all of the time? Biochar is mostly not bio-available carbon. It is mostly “fixed Carbon” (90-95% by weight). All of the “fixed Carbon” part biochar that is invested in soil will reminn in the soil, regardless of microorganism activity. It will not gas off, is not soluble in water, and sdoes not provide an energy souce like bio-available Carbon does. Bacteria cannot make use of it. It is NOT bio-available and will not be digested by microbes or expired as CO2. But plant waste do. Plant wastes also can be feedsotck for pyrolysis into charcoal/biochar.

Comment by Sean K. Barry, Minnesota

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