California wants to go carbon-negative. No one knows the cost

By the middle of this century, Gov. Jerry Brown wants California to pull more greenhouse gases out of the atmosphere every year than it puts in.

That vision will almost certainly cost Californians. No one can say how much, however, because no one quite knows how we’ll achieve it.

California has years of experience ramping up its use of renewable power, plugging ever more solar plants and wind turbines into the grid.

But eliminating the state’s greenhouse gas emissions altogether by 2045 — the goal of an executive order Brown signed last week — will require decarbonizing sectors of the economy that California’s climate regulations have not yet addressed, such as agriculture. It will require better, cheaper ways to store power, electrifying all cars on California roads and forcing airlines to switch to renewable jet fuel.

Then comes the truly hard part.