Distance is just a really bad proxy for environmental impact, though. Larger trucks are more efficient than smaller ones, rail is much more efficient than truc

Distance is just a really bad proxy for environmental impact, though. Larger trucks are more efficient than smaller ones, rail is much more efficient than trucking, and shipping is much more efficient than rail. (This is part of why I'm so strongly in favor of carbon taxes:. It means businesses can continue to be optimizing for lowest cost, and the tax reconciles places where cost and environmental impact currently diverge)