WHAT IS IT?
Biochar is simply another term for charcoal – specifically for fine-grained charcoal added to soil. Mixing some charcoal with the soil in your back yard garden of course isn’t geoengineering – (though it might not do anything good either), but trying to cool the entire planet with charcoal is.
Biomass is falsely classified as ‘carbon neutral’, despite overwhelming evidence to the contrary. Biochar advocates say we should collect and then char wood, agricultural “wastes and residues” or even crops and trees grown for this purpose, and then plough the resulting carbon-rich charcoal in soils. By doing this, they claim, we can end up with more carbon in the soil than would otherwise be the case and they describe the whole process as ‘carbon negative’.
Many biochar advocates, including those represented in the main lobby group, the International Biochar Initiative (IBI), speak about billions of tonnes of biomass being turned into charcoal, which is to be ploughed into soils, where it is supposed to create a ‘carbon sink’. Some IBI members even claim that if we bury enough biochar, we can sequester all of the carbon emitted from fossil fuel burning. In public, IBI members prefer to speak only about ‘residues’, but in scientific articles, many of them have made it clear that producing a billion or more tonnes of biochar a year would require a lot of extra land. Some, including the Chair of the IBI, have even called for “research in genetics and plant breeding is needed to develop new, high-yielding hybrids of cereal crops and dedicated biomass crops”.
Many hundreds of millions of hectares of industrial tree and crop plantations would be needed to produce such vast quantities of biochar – forests and farmlands would be stripped of residues, soils degraded, nutrients lost, and lots of emissions would result from transporting large quantities of biomass to facilities for burning….all of these considerations make biochar production on this scale, more, not less destructive.
The International Biochar Initiative is the umbrella organization representing most biochar advocates. They work to convey an image of working “to protect soils”, and to “alleviate poverty”. Yet in their partnership with the Carbon War Room, the IBI advocates for “applying overwhelming force” to get biochar included into various carbon trading schemes. This, they say, will require overcoming obstacles, including “slow UNFCCC recognision [and]limited support from wider climate science community/”.” The implication is that these obstacles should be overcome, regardless of the potentially quite valid concerns of members of UNFCCC or scientific community.
The IBI mainly represents start-up biochar companies (such as Biochar Engineering in the US, Pacific Pyrolysis in Australia or Carbon Gold in the UK) other firms and industry associations with biochar interests and consultancy firms. Several scientists are involved, however many if not most of them have related business interests. From palm oil industry representatives to agribusiness interests to oil companies, biochar is attracting ever greater support. Tim Lenton and Nem Vaughan described biochar as the most promising geo-engineering strategy, while Frank Raes, head of the climate unit at the European Commission’s Joint Research Centre, has dubbed it ‘geo-renovating’.
Officially, the IBI is careful not to use the term geo-engineering and to only speak about charring ‘residues’ and ‘waste’, yet many of their members promote something far bigger off the IBI website and several quite openly speak about geoengineering – the IBI’s regional group in India, for example calls biochar ‘a geoengineering initiative’. Some members of the IBI’s Scientific Advisory Committee also promote other types of geoengineering. The IBI routinely backs legislation which would reward biochar made not just from residues but from dedicated plantations or from loosely defined ‘excess biomass’ in US National Parks.
WHAT’S WRONG WITH BIOCHAR?
Even if we were to ignore the question of where all the biomass is to come from, biochar could still be bad news for the climate and for soils. Fine biochar dust is essentially soot, which can be blown away and further heat the planet. Nobody knows how much carbon in charcoal will stay in soil for how long, yet there is evidence that adding charcoal can help turn carbon which was already in the soil into CO2 in the atmosphere. And even if biochar helps plants access nutrients, plants need those in the first place and if all organic residues in sight are charred, synthetic fertilisers become the only option.
True, in some areas farmers have traditionally mixed some charcoal with compost and other residues and, over time, rich soils have been created this way, best known the Terra Preta soils in Central Amazonia which were created between 2,500 and 500 years ago. Yet nobody has ever charred vast quantities of biomass over a quick period of time and ploughed it into the land, most likely combined with fossil-fuel based fertilisers.
The biggest danger of biochar for geoengineering, however, is scale. Hundreds of millions of hectares of land likely needs to be turned over to new plantations in order to produce the quantities of biochar many talk about. Directly or indirectly, this will mean more deforestation, more destruction of other ecosystems, biodiversity losses and more land-grabbing and evictions.