I’d say when we’re talking about a dietary choice an individual makes, looking at carbon on a per capita basis is the right way to look at it. Especially given that the US consumer is a very influential one in the world. China is set to put a substantial chunk of global emissions under a carbon tax in the near term, which should prove to be a market force which drives down meat consumption, among other things.

The US agricultural system has global implications — from tooling and process, to subsidies and what poor countries grow. A fundamental change in the American diet would have an enormous ripple effect across the globe.