The Human Footprint

The Wildlife Conservation Society has some good analysis and a spiffy map (.pdf) of the human footprint on the world. Their analysis shows that only 17% of land in the world is still virtually untouched by humans. Only 2% of land where it is possible to grow rice, wheat or maize is untouched.

This raises the bigger question of whether there is a moral or ethical reason to try and set aside land just for nature/animals or whether the goal of humanity should be to maximize the number of humans that can live. Personally I would like to see more land/ecological resources set aside for nature. But, given the number of humans on the planet and the increasing population not quite sure how we get there. How much land should be set aside for national parks in an ideal world? I don't know but maybe 15% sounds like a good number. And not just the crappy deserts and arctic land. Some good quality highly ecologically productive land should be set aside as well.