My disagreement with Albert Bates at the Permaculture Convergence last year was his contention that biochar could be a solution to global warming if we just planted enough trees and cut them for biochar. That disagreement touched a range of issues:
- Peak water – if we tried to grow trees in marginal or arid/semi arid lands as he suggested we would quickly run up against the problem of water. We are already on the limits of fresh water use, if we haven’t already overshot, where does the water come from and what are the opportunity costs?
- Peak phosphorous (and in NZ trace elements such as boron, selenium etc) Again, we are reaching peak phosphorous without which growth will be much more limited than we would wish. Where do these critical minerals come from?
- Peak Oil – given that we are demonstrably in a peak energy plateau with an unknowable time to fall-off, it is critical to ask what is the energy cost of converting all these marginal lands to biomass production? How much fuel will we have to burn to feed and water and house the workers who will do all the planting, the machines to transport the seedlings, the mulches to support the seedlings, the nurseries to produce them, the milling, chipping and transporting etc before the first gram of biochar hits the soil?
Because if we haven’t calculated ALL of that, and done so in a factual environment with good numbers for depletion rates and time scales, we could easily get part way through and find ourselves unable to complete the projects, effectively wasting all of the resources that go into them.
But now Rachel Smolker has added a piece that I did not think of at the time. Ecosystems and markets.
Those marginal lands are already filled with their own ecosystems; have we calculated the costs of converting thnem to biomass production and what sort of repalcements will we create? Will they be biodiverse enviromnents in a permaculture mould or will we be going flat out for carbon sequestration and create yet more monocultures designed to suck CO2?
But her main target is the problem of markets and their political power. IF biochar becomes either an enviromental necessity, or the big players can extract rents from their political cronies, we will see something similar to what is happening as described in Smolker’s document,
Since humans first learned to manipulate fire, people have used local biomass—including wood, other plant matter, and dried animal dung—for heat and for cooking. Billions of people continue to do so. But now, in addition to these traditional uses there is an unprecedented push for large-scale industrial/commercial bioenergy.
This new trend includes refining plant materials (corn, wheat and other grains, sugarcane, soy and palm oil) to make liquid biofuels for transportation and burning plant materials (wood, agricultural residues, municipal waste, etc.) for heat and electricity. Less widely known is the development of plant-based petroleum substitutes for use in bioplastics, biochemicals, inks, fabrics, pharmaceuticals, and other products.
Proponents refer to a new “bioeconomy” featuring massive biorefineries that take in millions of tons of plant biomass and convert them into all manner of energy and materials.
But two important questions are often overlooked in the rush toward bioenergy: Where will all that plant biomass come from, and what will the consequences be on ecosystems, wildlife, agriculture, human rights, climate, water, and soil?
At the moment I am making char out of trees that have to come down both to protect my neighbour’s house and to open up the amount of light that falls across the middle of the block. The longer term aim to to significantly increase the total amount of biomass being generated by the property in the form of an edible forest and to use the prunings as the source of biochar, compost and firewood – including a woodlot.
I’m prepared to make a case that replacing old, slower growing trees with many more younger, faster-growing ones is possibly net carbon negative if the old trees are properly handled but we also acknowledge that the energy cost of managing the place chainsaws, mulchers, the tractor, WWOOFERS will leave us carbon positive for most of the rest of our lives.
We are doing this because, on balance, we believe that working towards a more sustainable future is better than doing nothing and that some kind of permaculture model is better than anything else we have seen and biochar is a part of that thinking..
I would be saddened to see the biochar revolution being co-opted into the mania for fuel production and contributing to raising the price of biomass and hence the temptation to continue eating the good stuff to make a financial profit.