Climate scientist James Hansen, Whole Earth Catalog founder Stewart Brand and other scientists and environmentalists are urging Governor Jerry Brown to let the state legislature, not the California Public Utilities Commission (CPUC) decide the fate of Diablo Canyon, which provides 21 percent of the state's clean power.



"Retirement of the plant will make a mockery of California’s decarbonization efforts," say the letter writers. "Diablo Canyon’s yearly output supplies 9 percent of California’s total in-state electricity generation and 21 percent of its low-carbon generation. If Diablo closes it will be replaced mainly by natural gas, and California’s carbon dioxide emissions will rise."



The CPUC has been struggling to regain credibility and legitimacy after having engaged in secret dealings with PG&E, which owns and operates Diablo Canyon, after a PG&E natural gas explosion killed eight people.



Meanwhile, Governor Brown has been seeking to reform the agency, and implement new climate legislation. The scientists and environmentalists argue in their letter that Diablo Canyon must be treated as part of a holistic strategy to deal with climate change.



The proposal to close Diablo Canyon, the letter writers note, was "decided in secret negotiations between PG&E and unaccountable anti-nuclear groups, some with financial ties to the renewables sector. Sending this proposal to the CPUC, an institution that is struggling with its own crisis of credibility relating to improper relationships with regulated industries, would raise further doubts about the legitimacy of the proceedings."



The letter notes that PG&E's proposal — endorsed by anti-nuclear groups NRDC and Sierra Club, which are invested in renewable energy and fossil fuel companies that could benefit from Diablo Canyon's closure — would not replace Diablo Canyon with power from clean energy sources.



"And much of the demand reduction PG&E forecasts to replace Diablo will come about simply from customers switching from PG&E to alternate electricity providers, with no guarantee that their new electricity supply will come from low-carbon sources," the letter notes.



Even were Diablo Canyon replaced by other forms of clean energy, the scientists explained, there would be no net reduction in emissions.

The cost of electricity would also rise. Under PG&E's proposal, ratepayers would pay a “non-by-passable charge” to make good decommissioning costs that would have been funded had Diablo completed a typical 60-year service life.

"The CPUC is not the right forum to decide on this important matter," the group of scientists and environmentalists said, "nor is a back-room deal dictated by special interests an appropriate framework for that decision. The loss of one-fifth of California’s clean electricity is of such significance as to merit the direct attention of the state legislature. These questions deserve a broad, considered and transparent discussion by the public and their elected representatives. We ask you to support this position, and to help initiate the public debate that needs to happen."