It is crucial for the world to identify, research, develop, demonstrate,
commercialize and deploy affordable and sustainable new energy sources. This need is driven by various factors; three of the most important are: (1) demand for energy to enable economic growth for a still-increasing global population, (2) concerns regarding the long-term accumulation in Earth's atmosphere of fossil fuel-derived greenhouse gases, and (3) the prospect that during the coming decades annual production of petroleum (and possibly other fossil fuels) will peak and begin to decline.
Continuing economic progress will require a four-fold increase in annual energy use by the end of the century. If carbon dioxide (CO2) emissions into the atmosphere are to be constrained during the same span, by 2100 some 90% of all energy used must be from renewable or nuclear sources. Notwithstanding optimistic claims to the contrary, it does not appear that there is at present a solution to these concurrent challenges.