It’s well known that trees capture CO2 in the atmosphere. As we look for strategies to reduce carbon(1), the idea of planting more trees is very attractive. In fact, some states have a carbon offset program that allows carbon polluters to offset their emissions by planting trees or preserving trees that would have been cut. Will the offset programs actually reduce carbon or could they even increase the amount of carbon in the atmosphere? In other words, what are the possible unintended consequences of a carbon offset program involving trees?
First we need to consider some facts about the carbon absorption of trees. The absorption of carbon by trees depends upon the type of tree, the local climate, tree density and other factors. The exact amount carbon capture is complicated. The amount of carbon capture is not static. Over time carbon capture can increase or decrease depending upon the health of the trees, their age, forest thinning, etc. Forrest lands capture carbon now. Carbon offsets should be for the preservation of forests that exceed what an average forest would already be capturing.
Now think about the unintended consequences. What might happen if the carbon absorption calculations underestimate the actual carbon absorbed? If this is the case, carbon emitters are putting more carbon into the atmosphere than is being offset by trees. This has actually occurred in some states.
What might happen if the trees used in the offset program are on lands that would never expect to be logged? In this case, carbon credits are essentially “given away” for no actual reduction in carbon. The carbon emitter is being given credit for no increase in carbon absorption. Thus the carbon emitter can release more carbon into the atmosphere.
Currently there is no federal carbon offset program. As a result one state could be giving credit for carbon absorption that came from another state. Carbon emissions don’t recognize state boundaries.
There is another issue with the lack of a federal program. While forced preservation may increase carbon absorption in one state, it’s likely to lead to more logging and less carbon absorption in another state. As a result, the net effect on carbon reduction may be zero.
There are other unintended consequences to explore. The question is how to explore them so that they can be prevented? Unintended consequences should be dealt with in the design stage, not after the fact when problems arise. Unfortunately this doesn’t often happen. The result is that worthy programs become tainted and discontinued.
What we need to see from program proposals is a list of anticipated challenges and mitigation strategies. What we don’t need are over-promised solutions and hype.
Just imagine how we might generate a series of questions to explore possible consequences of a new program. Just imagine how many worthy programs have been discontinued or harmed by failure to anticipate likely consequences of such programs. Just imagine what it might take to improve our processes for program design to anticipate consequences.
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“Always plan ahead: It wasn’t raining when Noah built the arc.” – Richard Cushing (Roman Catholic Cardinal)
(1)CO2 – will be referred to as just carbon in the rest of this message.