Fossil fuels provide about 80% of the world’s energy and, despite dire predictions since the early 20th century, supplies will not run out any time soon, according to speakers at a AAAS discussion on meeting global energy demand.

“Oil is good for 50 years at current consumption rates, [and] could be extended longer as you go to more difficult resources,” said Steven E. Koonin, under secretary for science at the U.S. Department of Energy. “Coal—there are hundreds of years.”