A transition from the global system of coal-based electricity generation to low-greenhouse-gas-emission energy technologies is required to mitigate climate change in the long term. The use of current infrastructure to build this new low-emission system necessitates additional emissions of greenhouse gases, and the coal-based infrastructure will continue to emit substantial amounts of greenhouse gases as it is phased out. Furthermore, ocean thermal inertia delays the climate benefits of emissions reductions. By constructing a quantitative model of energy system transitions that includes life-cycle emissions and the central physics of greenhouse warming, we estimate the global warming expected to occur as a result of build-outs of new energy technologies ranging from 100 GWe to 10 TWe in size and 1–100 yr in duration. We show that rapid deployment of low-emission energy systems can do little to diminish the climate impacts in the first half of this century. Conservation, wind, solar, nuclear power, and possibly carbon capture and storage appear to be able to achieve substantial climate benefits in the second half of this century; however, natural gas cannot.

Climate change, pollution, and energy insecurity are among the greatest problems of our time. Addressing them requires major changes in our energy infrastructure. Here,we analyze the feasibility of providing world-wide energy for all purposes(electric power, transportation, heating/cooling,etc.) from wind, water, and sunlight (WWS). In Part II, we address variability, economics, and policy of WWS energy.

Climate change, pollution, and energy insecurity are among the greatest problems of our time. Addressing them requires major changes in our energy infrastructure. Here,we analyze the feasibility of providing world-wide energy for all purposes(electric power, transportation, heating/cooling,etc.) from wind, water, and sunlight (WWS). In Part I, we discuss WWS energy system characteristics,current and future energy demand, availability of WWS resources, numbers of WWS devices, and area and material requirements.