Ecological footprint analysis is a method to evaluate the real demands made by each of us on earth's ecologically productive area by our patterns of consumption of food and wood products and our share of built up (ecologically degraded) land. A separate calculation of our energy footprint estimates the area of new forest that would need to be generated if we wanted to sequester all of the carbon emitted into the atmosphere from the burning of fossil fuels. Calculation of the current ecological footprint for each citizen of the United States shows that our style of consumption, which we market to the world, is not sustainable for the world population of approximately 9 billion people expected in 2050 if they wish to live as we do. Our food footprint can be significantly mitigated by reducing beef consumption by approximately 80%; our wood products footprint, if extrapolated to the world, exceeds the carrying capacity of earth's forests. We continue to degrade ecologically productive land beneath cities and the transport and business infrastructure that maintains our economy. Our energy footprint is so large that there is no realistic sink for the excess carbon dioxide we produce from the burning of fossil fuels. We need to know the consequences of this more clearly. We must face the reality of replacing our petroleum-based economy with alternative renewable energy sources during the twenty-first century. The challenge to bring human consumption into balance with earth resources for a sustainable and humane future, probably within two generations, is daunting.