My 5: Harry Johansing, Costa Rica Natural and EcoPaper

The Deepening Crisis: We are losing the margin of planetary safety as the world trespasses various thresholds of environmental risk. With the human population continuing to rise by 75 million or more per year and with torrid economic growth in much of the developing world, the burdens of deforestation, pollution, greenhouse gas emissions, species extinction, ocean acidification and other massive threats intensify. -- Jeffrey D Sachs, 2010 September issue of Scientific American (Hat tip to Bob Halstead.)