The threat to our climate is becoming graver with each passing year. As NASA scientist James Hansen noted in 2008, "If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleo-climate evidence and ongoing climate change suggest that CO2 [in the atmosphere] will need to be reduced from its current 385 ppm [parts per million] to at most 350 ppm."

That means that in order to decline equitably, Americans will need to cut their CO2 emissions (and thus fossil fuel energy use) by 90-95% by the year 2050, or about 4% per person per year. As the graph at right shows, we in the U.S. need to go from approximately 20 tons of CO2 per person per year, to just 1 ton. As the world’s largest emitter of greenhouse gases, we must not only make the largest cuts, we must lead the way.

By now you’ve also probably heard about Peak Oil, the idea that worldwide oil extraction will plateau due to limited sources, after which production will slow and begin an inevitable decline. What you may not have heard is that studies by a wide swath of groups – the US Army Corps of Engineers (2005), the Energy Watch Group in Germany (2006), the Association for the Study of Peak Oil (2007), and the International Energy Agency (2008) – conclude that Peak Oil may have already arrived, or will likely begin by 2015 at the latest. Our other fossil fuels are in short supply as well; natural gas is projected to peak by 2020 and coal by 2030. (Read a Q&A on Peak Oil here.)

Even companies that have the most investments in oil, and the financiers who invest in oil exploration, are giving off clear signals that they know the game is nearly up. While companies like Shell, ExxonMobil and BP have posted record profits in the last few years, these same companies are spending less and less on finding new oil, as the cost of exploration has already begun to exceed the revenue from the oil discovered. "The great merger mania is nothing more than a scaling down of a dying industry," said Goldman Sachs in a 2004 report, "in recognition of the fact that 90% of global conventional oil has already been found."

So, given that our insatiable demand for energy is generating climate-threatening levels of CO₂, and that we're also running out of the fossil fuels burned to create that energy, and given a world population that just keeps expanding, what can we do?

This is the question we encourage you to ask yourself, and to pose to other members of your community. Our answer is Plan C.