A Critical Conversation on Climate Change ... - Green Choices

lessons unlearned 153Sinks, biophysics and the unknownSome of the worst trouble that carbon market planners have landedthemselves in has come about as a result of credit-generating schemesthat purportedly soak up carbon dioxide through tree-planting orother biotic means. There are even more verification problems withthese ‘carbon sink’ projects than with other ‘offsets.’Don’t tell me. How could things be any worse?From the beginning, climate technocrats have been under heavy pressureto try to operate a ‘system of credits and debits wherein emissionor sequestration of carbon in the biosphere is equated with emissionof carbon from fossil fuels’. 311 They’ve been pushed into trying toprove that a world which closes a certain number of coal mines or oilwells will be climatically equivalent to one which keeps them openbut plants more trees, ploughs less soil, fertilises oceans with iron,and so forth.So the idea is that if you plant enough trees, you can go on mining and burningfossil fuels forever.Well, not exactly. Even the biggest fans of tree ‘offset’ projects admitthat there’s not actually much scope for using tree-planting to dealwith the climate crisis.As Chapter 1 noted, the pool of carbon stored in living biomass isdwarfed by the pool of remaining fossil carbon awaiting exploitation.Under the most favourable assumptions, using trees even to try to‘compensate’ for current emissions would require protecting impossiblecontinent-sized plantations rigorously for decades. 312 Trying tocounteract a single year’s emissions in the UK would necessitate coveringDevon and Cornwall with trees. 313 Doing the same for a singleyear’s global emissions would mean, at a minimum, setting up andprotecting industrial plantations on all ‘available’ land in Brazil forthe next 40 to 50 years. 314 Attempting to absorb the carbon dioxidereleased by the burning of the fossil fuels still in the ground wouldrequire additional planets full of trees. As a distinguished group ofscientists writing in Science concluded:Prospects of retrieving anthropogenic CO 2 from the atmosphereby enhancing natural sinks are small… There is no natural ‘saviour’waiting to assimilate all the anthropogenically-producedCO 2 in the coming century. 315A similar point applies to projects producing biofuels to replace petroleum.Gigantic plantations would be required just to replace a tiny