Progress Toward a Tokamak Fusion Reactor

Nearly 90% of the world's energy needs are today supplied by fossil fuels. Long‐term reliance on fossil‐fuel energy sources, however, is acknowledged to be a dangerous strategy—despite the large reserves of coal available in the US and elsewhere. Use of fossil fuels exacerbates pollution and acid rain and heightens the risk of global warming by adding ${\mathrm{CO}}_2$ to the atmosphere. Society will be served best if energy production in the next century uses environmentally attractive methods that do not involve the combustion of fossil fuels. (See the article by John H. Gibbons and Peter D. Blair in PHYSICS TODAY, July 1991, page 22.) The long time required to develop and implement new large‐scale energy technologies—on the order of decades—underscores the urgency of the need to accelerate development of alternative energy sources.