White House science adviser Arati Prabhakar, appearing with Granholm, called the fusion ignition “a tremendous example of what perseverance really can achieve” and “an engineering marvel beyond belief.″Proponents of fusion hope that it could one day produce nearly limitless, carbon-free energy, displacing fossil fuels and other traditional energy sources.Billions of dollars and decades of work have gone into fusion research that has produced exhilarating results — for fractions of a second.Previously, researchers at the National Ignition Facility, the division of Lawrence Livermore where the success took place, used 192 lasers and temperatures multiple times hotter than the center of the sun to create an extremely brief fusion reaction.US scientists set to announce fusion energy breakthroughEXPLAINER: Why fusion could be a clean-energy breakthroughColorado River water users convening amid crisis concernsStarving seabirds on Alaska coast show climate change perilNet energy gain isn’t a huge surprise from the California lab because of progress it had already made, according to Jeremy Chittenden, a professor at Imperial College in London specializing in plasma physics.Maddie Burakoff reported from New York, Michael Phillis from St. Louis and Jennifer McDermott from Providence, R.I.___Associated Press climate and environmental coverage receives support from several private foundations."