The theme for this special issue is "Crossroads for Planet Earth." In the introduction, we'll hear how the next 50 years will be decisive in determining whether the human race can ensure the best possible future for itself. Then, "The Human Population Grows Up" as our numbers swell toward more than nine billion. Also, "Sustaining the Variety of Life" without breaking the bank, and making "More Profit with Less Carbon" through efficient energy use. Finally, we'll hear a policy-focused article that asks "How Should We Set Priorities?"
©2005 Scientific American