I remember when real environmentalists drove smoking VW vans with bumper stickers that said stuff like, "You can't call yourself an environmentalist if you eat meat." They didn't get the best gas mileage, but hey, you could do worse. They were replaced by the forest-green Subaru Outback (Eddy Bower edition if you were really cool), seen by the dozens in any REI parking lot. These are presently being eclipsed by the ubiquitous Prius. But, there is stiff competition from the diesel Jetta replete with biodiesel stickers all over the butt end.
As we all know by now, biodiesel can be made out of a lot of things:
Soybeans: 50 gallons per acre
Rapeseed: 150 gallons per acre
Jatropha: 175 gallons per acre
Palm oil: 650 gallons per acre
To limit the impact on the planet, maybe we should start pressuring our biodiesel distributors to sell fuel made only from palm oil? According to the World Wildlife Fund, we would also need to demand that it be made out of palm oil grown only on degraded, non-forested land: