A major component of California's crusade against global warming, one started by former Gov. Arnold Schwarzenegger and embraced by successor Jerry Brown, is the legal mandate to have 33 percent of electric power sales from "renewable sources" by 2020.
The latest version of the mandate, signed by Brown last year, defines biomass, thermal, photovoltaic, wind, geothermal, fuel cells with renewable fuels, small hydroelectric projects, digester gases, landfill gases, ocean wave and tidal current generation, ocean thermal, and conversion of municipal solid waste into clean-burning fuel as officially blessed.
The list obviously excludes California's largest single source of electric power plants burning natural gas and, of course, coal-burning plants in other states. Converting hydrocarbons to electricity releases carbon dioxide into the atmosphere.
It also excludes nuclear power, which doesn't emit carbon and accounts for about 11 percent of California's electricity, but does have an unresolved waste disposal problem.
The more curious exclusion, however, is large-scale hydroelectric power generators, usually connected to dams, that use falling water to spin turbines.
Hydro, which doesn't emit carbon dioxide, already accounts for about 12 percent of the state's power supply, according to the state Energy Commission.
So, one might wonder, if the goal is to reduce carbon dioxide emissions why don't we count hydro against the carbon reduction mandate? What, after all, could be more renewable than water power?
The answer: Political correctness.
Environmentalists dislike big dams because they're big, because they slow the seasonal free flows that river rafters like, and because some, but not all, interfere with fish spawning.
Those may or may not be reasons not to build new dams.
But what about the dozens of dams that already exist? It's a good thing they do exist, because life as we know it in California would be impossible without dams and reservoirs to capture seasonal flows, prevent flooding and supply water to homes, factories and farms during the dry season.
Those dams also generate a lot of energy, so what would be wrong with counting the power they already generate against the non-carbon energy mandate, rather than pretending they don't exist?
Sen. Anthony Cannella, R-Ceres, proposed a step in that direction with legislation that would have subtracted hydropower before calculating the 33 percent mandate on the remaining power supply.
However, the bill supported by utilities but opposed by environmental groups and generators of approved sources of renewable power was trashed in the Senate Energy, Utilities and Communications Committee.
It's another victory of ideology over rationality.
Editor's note: This story has been updated from online and print versions to correct the committee that defeated SB 971 to the Senate Energy, Utilities and Communications Committee. Updated 3:45 p.m., May 22, 2012.