Bitter scientific debate erupts over the future of America's power grid

Scientists are engaged in an increasingly bitter and personal feud over how much of the United States' power it can get from renewable sources, with a large group of scientists taking aim at a popular recent paper that claimed the country could move beyond fossil fuels entirely by 2055. In 2015, Stanford professor Mark Jacobson and his colleagues argued that between 2050 and 2055, the U.S. could be entirely powered by "clean" energy sources and "no natural gas, biofuels, nuclear power, or stationary batteries are needed." That would be a massive shift from the current power makeup, as in 2016, the United States only got 6.5 percent of its electricity from hydropower, 5.6 percent from wind, and 0.9 percent from solar. Nonetheless, the paper excited proponents of renewable energy, and has been embraced by Sen. Bernie Sanders, celebrity backers such actor Mark Ruffalo, and many environmental groups.But Jacobson's idea was always contentious. And now, no fewer than 21 researchers have published a study in the influential Proceedings of the National Academy of Sciences (which also published Jacobson's original study in 2015) arguing that the work "used invalid modeling tools, contained modeling errors, and made implausible and inadequately supported assumptions." "We thought we had to write a peer reviewed piece to highlight some of the mistakes and have a broader discussion about what we really need to fight climate change," said lead study author Christopher Clack of the National Oceanic and Atmospheric Administration's Earth System Research Laboratory. "And we felt the only way to do it in a fair and unbiased way was to go through peer review, and have external referees vet it to make sure we're not saying anything that's untrue in our piece."Clack is backed in the study by a number of noted colleagues including prominent climate research Ken Caldeira of the Carnegie Institution, energy researcher Dan Kammen of the University of California, Berkeley, and former EPA Science Advisory Board chair Granger Morgan.In a simultaneous letter in the journal, meanwhile, Jacobson and three Stanford colleagues fire back that Clack's critique is itself "riddled with errors" and "demonstrably false."