My friend Casey helpfully pointed to a study from a well-respected author, though working at an environmental organization. I snip the following from Table 8 of his piece:

	CO2	CH4
Total US emissions reduced by recycling (%)	1.5	9.0

These are the main greenhouse gasses (after water vapor, which stirs another thought, but we’ll get to that later), and recycling saves 1.5% CO₂ over what they would otherwise be. That’s nearly a rounding error, and probably close to his confidence interval, but we can say it’s at worst a wash with a less serious greenhouse gas being reduced noticeably (CH₄ at 9%).

So recycling is a net win, albeit a slight one, for greenhouse gas reduction.

That question settled, it brings to mind another question. Since it’s also fairly settled that, aside from aluminum, recycling always costs more than virgin production, the question turns to one of political economy: what is the opportunity cost of recycling? What other uses could the money spent on recycling be put, and would they get a bigger reduction in greenhouse gas emissions than recycling?

I’m not arguing anybody should stop recycling. All else being equal, it’s irresponsible not to recycle as much as you can. As an individual, using virgin products and landfilling your trash will definitely make your summers hotter and your weather more unpredictable.

Nevertheless, the public policy question of recycling versus other uses for the money should be asked, and answered with a view to the likelihood of implementing alternatives. If we could theoretically pump money into sequestration projects and reduce more atmospheric CO₂ than simply by recycling, it’s still pointless to stop recycling if the political capacity to transfer all those locally-spent funds to sequestration isn’t there.

But if we’re serious about global warming, it’s a good question to ask and answer.