Planting trees does indeed trap carbon but, as Cecil points out in “Nature, fossil fuels, and global warming…”, the tree will eventually die and release much of its carbon back into the atmosphere. But Cecil makes the mistake of stopping there.
One reason for planting trees is so that the trees can be harvested when they reach maturity. The carbon is trapped forever in wood and wood byproducts such as paper or houses or whatever. Well, maybe not forever – but some wood products stay around for centuries.
But the main reason for cutting the trees is to stuff them back into all those empty coal mines and burying them – putting the carbon back where we found it. Granted, this will stick in the craw of those worshipping at the First Church of Conservation, where conservation is the Word handed down from God and never to be questioned, but normal people can see some advantage in actually burying the carbon.
The fact is, the conservationists too often have tunnel vision. They see the control that conservation gives them over other peoples’ lives, the money, and the political power and they forget that maybe there really are other approaches.
I think we should turn plantation timber farms over to this purpose. But before we put those trees back in the ground, we turn them into charcoal. Why? Because charcoal is a more concentrated form of carbon than coal is, and it releases the other nutrients that would otherwise be bound up in the buried wood.
And we would keep the timber workers in employment as charcoal burners.
And second, what’s the advantage of specifically putting the carbon back where we got it from? The important part of sequestration is that it’s out of the carbon cycle, not where specifically it’s out of the cycle. If we can get some use out of the wood in the process of sequestering it (like by making houses, furniture, or books out of it), why shouldn’t we? I mean, I suppose that if we completely saturated the market for wood, and needed some other place to store all of it, old coal mines (if there are any) are as good a place as any, but we’re far from that point. And even that assumes that there’s such a thing as an “empty coal mine”: Most modern coal mining techniques don’t leave behind a hole in the ground.
Sure, a little less, yes. But that’s compensated for by the fact that the carbon thus stored will never ever be released; if it was just thrown down old coal mines as whole trees they’d decay and no doubt some CO2 would reach the surface.
Plus there would be transportation costs associated with bringing the trees to the mines, which uses resources associated with creating, maintaining, and using the transportation (even if it may be green transportation it still uses resources.)