Monday, November 12, 2007

Health Globally, Health Locally

There's talk of promoting the "co-benefits" from using one's own energy to get to school or work:
direct health benefits through the physical exercise, and indirect health benefits through reducing greenhouse gas emissions, smog, vehicular accidents, and so on.

I'm all for it.

Of course, it's a bit sad that such an obvious connection needs a public education campaign.

And when they get talking about co-benefits from reduced meat consumption, I have to raise my usual qualification about the local (and global) benefits of consuming range-fed beef where the land is marginal for crop production.

But this story also brings to mind a caution I raised last summer. When human bodies lose weight, where does the carbon go?


MojoMan said...

Interesting question about where the carbon from weight loss goes. I just started thinking about this relative to logs I may burn in my woodstove. I think perhaps this sort of "biological carbon" is largely carbon neutral. When the plants and trees grow to produce food or biofuel, they capture carbon. When we respire or enjoy the warmth of a fire, we are simply cycling the carbon back. Burning fossil fuel, on the other hand, is releasing carbon that would have stayed locked safely underground forever.

arcolaura said...

Well, more or less forever. I think of it as a matter of scale. The carbon cycle operates on a variety of time scales. The living things we see around us store carbon for a mere blink of time, release it, and store it over again. As long as the total existing biomass is fairly stable, adding and removing biomass is carbon neutral because the additions and removals are in balance.

The trouble with fossil fuels is that they built up over huge spans of time, and as they built up, because they built up, carbon was removed from the shorter biomass-atmosphere cycle. Now we are putting that carbon back in again in an incredibly short time, and slow-acting natural cycles can't remove it anywhere nearly that fast.

I noticed your discussion of the problems with biofuels. There is a fundamental problem with biofuels as a substitute for fossil fuels, and again it comes down to time scales, as discussed on this blog last year.