Encounter with a knowledgeable extra-terrestrial. I was recently visited by a learned alien from a distant planet (he didn't say which), who wished to find out how we Earthlings face up to the environmental and food threats that are compromising humanity's very survival. He seemed to know a great deal about our situation. He knew that, without rapid and radical intervention, our current system of development would quite simply collapse in less than a century. The plant and organic cover that...