Earth: An environmental writer mainstreams an idea floating around the green fringe — save the earth by population control and give carbon credits to one-child families. Are we threatened by the patter of little carbon footprints? New York Times environmental writer Andrew Revkin participated in an Oct. 14 panel discussion on climate change with other media pundits titled "Covering Climate: What's Population Got To Do With It?" People who need people they are not. In a recently rediscovered book, "Ecoscience: Population, Resources, Environment," co-authored with Malthus fans Paul and Anne Ehrlich, Holdren wrote that families "contribute to general social deterioration...