Global warming, population, deforestation, mass extinctions—according to environmental groups and environmental scientists, the earth is in ever more dire straits. Should we heed these warnings and take steps to mitigate our impact on the global ecosystem? Danish statistician Bjørn Lomborg has come forward to say, not so fast. He claims the environmental state of the world is actually improving, not getting worse. His claims have generated a firestorm of condemnation in the scientific community. Why? And how can we in the general public separate ideology from fact in this debate?