Monday, July 25, 2005

The stopgap solution

Winston Peters has revealed his party's plan to reduce greenhouse emissions and thereby avoid having to buy carbon credits on the international market: plant more trees. It's a stopgap measure which won't solve the ultimate problem, but at least he's trying. Unlike, say, the parties who are sticking their fingers in their ears like children and saying "lalalalalala"...

Will it work? Sure - temporarily. Forests absorb carbon dioxide, so putting more land under forest will gain us more credits with which to offset emissions. The problem comes in twenty years time; in order to keep the credits, the land-use change must be permanant - so we can't cut them down (or rather, we can't cut them down without replanting). Forest sinks are therefore only a stopgap measure - but they are a useful one, and an essential part of the policy mix. In the long term, we need to work towards emissions reduction through more efficient energy use and better technology, but trees are going to be required to cover the gap until then.

I also have no idea of whether Winston's numbers add up, or whether he has pulled them out of his arse in order to sound impressive (they're suspiciously large and round). But I was planning to look at the efficicacy and cost of further forest sinks anyway, and this just gives me an excuse.


Forest sinks are a boondoggle - You've got to clear and break the land to put the trees in (and so the cleared and turned up land becomes a net producer of CO2 due to soil rottage and fungal stuff for about five years as the ground recovers from being turned up to plant the trees.) Then they do take in CO2 as the trees grow, but only for about another ten or fifteen years; by the time the trees are mature, its in equilibrium, emitting as much as it takes in.

Now, everyone's assuming we can put in monoculture forests, and harvest them, which as you have observed, isn't an option if you want to fix the CO2.

Posted by Weekend_Viking : 7/25/2005 12:36:00 PM