Biochar: Environmental and Socio-Economic Issues

The toxins question

Two toxins are especially of concern with regard to biochar because they are associated with combustion processes. They are polycyclic aromatic hydrocarbons (PAHs) and dioxins. How often these are found in charcoal and in what concentrations is, according to CSIRO, “inadequately researched”. While charcoal samples have been found to contain PAHs, CSIRO says these are “not at environmental risk level.” However, it adds, “a more systematic evaluation for a more complete range of other potentially harmful chemical contaminants associated with combustion, as well as toxic substances within feedstocks, has not been made.”

Similarly, an environmental risk assessment of the impacts of these toxins on terrestrial or aquatic ecosystems has not been done. CSIRO says that such an assessment is critical for three reasons: “the irretrievability of biochar once added to soil, the apparent general permanency of biochar once in the soil and the scale and speed at which the strategy needs to be implemented to contribute to climate change mitigation.”

Biochar vs people or ecosystems?

Many of the problems identified with biochar center on the conversion of large areas of land to charcoal production.

An open letter signed by a variety of NGOs from across the world warns against large-scale production of charcoal as “a new big threat to people, land, and ecosystems.” It says that converting large areas of land to produce charcoal “poses a major threat to biodiversity and ecosystems that play an essential role in stabilising and regulating the climate and are necessary to ensure food and water security” and “threatens the livelihoods of many communities, including indigenous peoples.”

Critics of industrial charcoal production object to generalizations about the supposed benefits of a technology that is still poorly understood. Biofuelwatch warns that given the limited knowledge available at present, “there are likely to be serious and unpredictable negative impacts if this technology is adopted on a large scale.”

One of the most influential critics of charcoal has been the journalist George Monbiot. He writes scathingly of Chris Goodall’s book Ten Technologies to Save the Planet, which champions large-scale charcoal production as one of those ten technologies: “[Goodall] abandons his usual scepticism and proposes we turn 200m 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’.” Monbiot asks, “This is environmentalism?”

Such plans are seriously being put forward. Carbonscape, a company that hopes to be among the first to commercialise charcoal production, talks of planting 930m hectares for charcoal. The energy lecturer and biochar proponent Peter Read proposes new biomass plantations of trees and sugar covering 1.4bn hectares. The problem is, the world’s total cropland only comes to 1.36 billion hectares. If Read’s plan were followed, Monbiot writes, “we would either have to replace all the world's crops with biomass plantations, causing instant global famine, or double the cropped area, trashing most of the remaining natural habitats.”

Read was one of the promoters of first-generation liquid biofuels, which played a major role in the rise in the price of food in 2008, causing food shortages worldwide. Monbiot, who sees biochar as the next disastrous techno-fix in the pipeline, asks, “Have these people learned nothing?”

Read suggests that new charcoal plantations be created on "land on which the occupants are not engaged in economic activity". Read and Carbonscape call such lands “degraded”. Monbiot is skeptical, saying that this term means “land used by subsistence farmers, pastoralists, hunters and gatherers and anyone else who isn't producing commodities for the mass market: poorly defended people whose rights and title can be disregarded.”

Biofuelwatch agrees, saying that just as there are “no large quantities of wastes and residues lying around unclaimed” for use as feedstock, nor are there “vast expanses of ‘marginal and idle’ lands.” Biofuelwatch warns that such terminology dangerously excludes land uses that are not seen as contributing to global financial markets even though they are crucial to the livelihoods of small farmers and rural peoples.

An article for Links, an Australian journal, says that including industrially produced charcoal in carbon trading schemes would have disastrous effects on food security in the developing world: “An assured world market for biochar would turn the substance into an internationally traded commodity. Biochar is non-perishable and easily transported; give it a further boost by allotting it carbon credits, and producing it for export would in all likelihood yield better profits in developing world settings than growing food crops.”

Effects of industrial scale charcoal plantations on biodiversity have also attracted criticism. Chris Goodall suggests that biochar plantations could maintain a profusion of animals and plants in the forests that would be cleared by planting a mixture of fast-growing species, rather than a monoculture. But the Amazon ecologist Philip Fearnside says that a mixture does "not substantially change the impact of very large-scale plantations from the standpoint of biodiversity".

Biochar and agrofuels

Many objections to the industrial production of biochar center on the diversion of land from small-scale farming and food production to industrial agriculture and large-scale plantations of non-food crops. This argument also applies to the production of agrofuels. Indeed, biochar and agrofuels are being promoted by the same multinational companies. This is no coincidence, as charcoal is a byproduct from a type of bioenergy production which can also be used to make second-generation agrofuels, i.e. liquid agrofuels from wood, straw, sugarcane residues, palm kernel residues and other types of solid biomass.

Resources

• See main page: Biochar
• Biochar: Carbon Sequestration
• Biochar: Effects on Soil and Crops
• Biochar Lobby