The end of the fossil fuel age is now in sight. As the world lurches from one energy crisis to another, fossil fuel dependence threatens at every turn to derail the global economy or disrupt its environmental support systems. If we are to ensure a healthy and prosperous world for future generations, only a few decades remain to redirect the energy economy.  Though it has fueled the economic boom of the past 40 years, petroleum is no longer a reliable source of energy. Three severe oil shocks in 17 years are a clear warning that the world cannot continue indefinitely along a path of petroleum dependence. The ultimate constraint is phys-ical- oil supplies are finite but the immediate limits are geographical and political: nearly two-thirds of the world's proven oil reserves are in the volatile Persian Gulf region.

The end of the fossil fuel age is now in sight. As the world lurches from one energy crisis to another, fossil fuel dependence threatens at every turn to derail the global economy or disrupt its environmental support systems. If we are to ensure a healthy and prosperous world for future generations, only a few decades remain to redirect the energy economy.  Though it has fueled the economic boom of the past 40 years, petroleum is no longer a reliable source of energy. Three severe oil shocks in 17 years are a clear warning that the world cannot continue indefinitely along a path of petroleum dependence. The ultimate constraint is phys-ical- oil supplies are finite but the immediate limits are geographical and political: nearly two-thirds of the world's proven oil reserves are in the volatile Persian Gulf region.