The United States could run almost entirely on clean energy by 2050, with a larger economy, $5 trillion in savings––and no acts of Congress. That's a vision of the future as seen by Amory Lovins, a sustainability expert who talked about how to reach that goal in a presentation Tuesday at Harvard University in Cambridge, Mass.
Electric vehicles, retrofits, the sharing economy and the rise of clean energy in Europe and China—all these technologies and trends show how a transition from oil, coal and nuclear power is possible, he said.