What if California Cut Its Global Warming Pollution 80% and No One Noticed?

OK, California hasn’t cut its emissions that much yet, but in May the California Council on Science and Technology published an important study of how California could reach the 80% reduction target first set by The Governator, Arnold Schwarzenegger in 2005. No one seemed to notice.

Then last week, Jane Long, one of the study committee co-chairs, published her take on the report’s findings in a short essay in Nature and Andy Revkin picked up the story from there in his blog. Unfortunately, Revkin gave short shrift to the report’s finding that California could achieve a 60% reduction by aggressively deploying existing technologies and chose to focus on the report’s conclusion that “significant innovation and advancements in multiple technologies” would be needed to push the reductions from 60% to 80%. Revkin compounded the problem by asserting that California was a best case scenario, when the opposite is true. (To his credit, Revkin posted a note from Alan Nogee pointing out that it’s harder to achieve an 80% reduction in California than in other states because it is starting from a relatively low-carbon baseline. I would add that California’s population is growing much faster than the national average, compounding its challenge. See Figure 1 from the report).

Rather than pile on to the rancorous and somewhat silly debate about whether the California study supports a “deploy, deploy, deploy” strategy or an R&D strategy (isn’t it obvious that we need to do both?) I would like to try to return attention to the original study.

The report, called “California’s Energy Future: The View to 2050,” deserves our attention because it carefully constructs scenarios (the report calls them “portraits”) for what a low carbon energy system could look like. In doing so it is careful to avoid double counting and to consider interactions between sectors (you can’t reduce the same ton of carbon both by switching from gas to solar and by switching from incandescent bulbs to L.E.D.s; similarly you can’t use the same ton of biomass to produce electricity and liquid fuels). This approach produces a number of important insights. Here are three that stood out for me:

1. Strategies to achieve deep reductions sometimes differ significantly from strategies for more modest near-term cuts. For example, in the short run switching from electric resistance space and water heating to natural gas reduces carbon emissions significantly because it is far more efficient to burn the gas directly for heat than to burn gas in a power plant and use the electricity to heat up a wire. In the long run, however, the emissions from all of those individual gas burners can’t be captured and would make it impossible to achieve an 80% reduction target. One solution is to decarbonize electricity production and use the electricity to drive high efficiency heat-pumps. Replacing natural gas with bio-methane or solar hydrogen could also work.
2. In the long run we can’t rely on natural gas generation to “firm” intermittent renewable electricity sources. (This is a special case of number 1.) In the short term we can expand reliance on renewables and rely on the grid to balance supply and demand. This includes demand side management (e.g. using “smart” devices to shift electricity demand to reduce peaks) and dispatching power plants that can follow the load--primarily natural gas plants as of now. The California study, however, shows that relying on natural gas power plants for load balancing could bust the 2050 target, assuming this means generating 20% of 2050 electricity from gas (without carbon capture). The report recommends more attention to developing “zero emission load balancing” approaches. This could include some combination of carbon capture at natural gas plants, energy storage, and smart grid enhancements.
3. Emission reductions from transportation must look beyond the light duty fleet. One of the bright spots over the last few years has been progress in setting fuel efficiency and carbon pollution standards for passenger vehicles starting with the historic “clean car peace treaty” between EPA the Department of Transportation and California for 2012-2016 model year cars. Those agencies are now in the process of setting standards out to 2025 which should cut average emissions from new vehicles by about half. As plug-in hybrid and pure electric vehicles are being introduced on the market the pathway to near-zero emissions from passenger vehicles is emerging: Electrify as much as possible (recharging with renewable electricity) and use sustainably produced biofuels for the remaining liquid fuel demand. The challenge for aviation and long-distance trucking is much harder. Electricity simply isn’t an option. Fuel options include biomass-derived drop-in replacements for diesel and jet fuel and hydrogen, but significant innovation is needed to make either pathway sustainable and economically viable. Another possibility worth exploring is integrated production of electricity and fuels from a combination of biomass and fossil fuels with carbon capture and storage to produce net zero-emission fuels. Also, more systematic changes to transportation infrastructure (such as high speed rail integrated with electrified short-haul delivery vehicles) could potentially reduce truck and air miles much more significantly than considered in the study.

One of the really cool things about the California Energy Future study is that its analysis is fully transparent. In fact, they made their spreadsheet freely available for download. So if you don’t like their assumptions or “portraits,” or the ideas I sketched out here, you are free to substitute your own. The spreadsheet will help make sure you aren’t double counting or ignoring interactions between sectors. 

This study deserves more serious attention. And not just in the form of spin battles.