If we do not learn...

"If we do not learn to eliminate waste and to be more productive and more efficient in the ways we use energy, then we will fall short of this goal [for the Nation to derive 20 percent of all the energy we use from the Sun, by 2000]. But if we use our technological imagination, if we can work together to harness the light of the Sun, the power of the wind, and the strength of rushing streams, then we will succeed. "

-- US President Jimmy Carter (1979).