What then, if a deep, hard look at California’s ambitious plans to lower its greenhouse gas emissions revealed that – even by pursuing an all-out, no-holds-barred mix of today’s technologies and aggressive efficiency measures – the state was only likely to get about halfway towards its goal?

That, roughly, is the conclusion that Jane C. S. Long comes to in a commentary published in the journal Nature last October. Titled Piecemeal cuts won’t add up to radical reductions, her note maps out, with remarkable clarity, the mountainous challenge ahead for California to achieve its climate goal. The bracing conclusion: California can’t just spend or deploy its way to an 80 per cent reduction or beyond – and neither can anywhere else.

Jane’s expertise stems from her role as co-leader of a team of energy analysts who wrote California’s Energy Future: The View to 2050 published in May 2011. By day, she’s principal associate director at Lawrence Livermore National Laboratory, a global leader in research on energy technologies and policy.

One of the important implications that surfaces in Jane’s broader analysis is the central role of carbon capture and sequestration (CCS). This is somewhat surprising given that California’s grid is all but coal-free.

California is different from most states, she observes, with 40 per cent of total energy used for transportation, versus 25 per cent nationally. Thus CCS must come into play less so for grid power than to help generate low-carbon vehicle fuels and other applications where neither electricity nor biofuels can substitute for existing fossil fuels.

The model Jane and her team developed strives to avoid what she calls ‘sleights of hand’ where it can be difficult to fully account for the secondary or tertiary impacts induced by switching to new energy forms. For example, rather than simply count solar panels as clean generation, Jane’s model more fully enumerates the impact of electric power generation at night and other times when solar panels are off line.

The analysis reveals that to achieve a 60 per cent reduction – well short of the 80 per cent goal California and many nations are looking to – would require all manner of tough-to-imagine steps:

[The state would have to] replace or retrofit every building to very high efficiency standards. Electricity would have to replace natural gas for home and commercial heating. All buses and trains, virtually all cars, and some trucks would be electric or hybrid. And the state’s entire electricity-generation capacity would have to be doubled, while simultaneously being replaced with emissions-free generation. Low-emissions fuels would have to be made from California’s waste biomass plus some fuel crops grown on marginal lands without irrigation or fertilizer.

Given that California represents a best-case scenario for the rest of the US, Long’s assessment is a compelling case to accelerate the speed and scope of carbon-reduction efforts.

I’ll refrain from diving into the broader implications of her report here – better to check it out in whole. Instead, for the Global CCS Institute’s community, I wrote to Jane to tease out a bit more of her vision of CCS in California’s future. An edited version of our exchange follows.

Adam: You’ve said that CCS has a critical role in helping California achieve its goal of cutting emissions to 20 per cent of their 1990 levels by mid century. How so?

Jane: I would guess that CCS will not play much of a role in meeting the AB32 goals of 20 per cent reductions, but it may play an important role in meeting the longer-term goal of 80 per cent reductions by 2050. Natural gas generation is a large part of California’s electricity portfolio. If this is to continue and meet the emission reductions, CCS would have to be used whether or not that generation was within state or say, by wire from Wyoming.

In the long term, CCS may play a critical role in solving the fuel problem. We are unlikely to have enough biofuel to meet all of our demands for fuel even if we are successful in cutting demand in half through efficiency measures and electrifying everything we can. CCS could be part of a hydrogen scenario where we get hydrogen from methane and sequester the CO₂ generated in this process. Or we might use biomass to make electricity and sequester the emissions to create a negative emission credit to counter the continued use of fossil fuels.

Adam: Yet CCS technologies remain immature and under-commercialized. Starting in what years would CCS need to begin entering into California’s energy mix to play this kind of role? And are we already behind that pace?

Jane: If we start now with demonstration projects, it could be possible to have all new fossil generation be using CCS within a few decades. We need that amount of time to be sure the demonstrations are working.

Adam: What lessons does California’s CCS case have for the transportation challenge in other countries?

Jane: The transportation problem in the developing world is really interesting because it’s not clear that countries like India, for example, should electrify automobiles as a first strategy. If their electricity is made with coal without CCS, electrification is not a clear benefit. If they move to de-carbonize electricity, then electrification of transportation and heat makes much more sense.

Adam: I’ve assumed that developing countries such as China and India ought to leapfrog to electric fleets ahead, and skip the oil-burning stage, to whatever degree possible. You’re suggesting that might not be the best bet for the climate?

Jane: The distance countries like China and India have to go to provide enough electricity at low emissions is huge. If having to run cars on electricity means they add twice as much coal-fired electricity without CCS it would be a disaster. As well, the biomass for biofuel problem is likely to be more acute in these countries as they face serious challenges with food supplies. In the same 2050 period that we are looking to more than double energy supply, we are looking to double food supply. As it takes some time to roll over the fleet of automobiles to electric vehicles, it probably makes sense to move forward with electric transportation at some level as this is what we need in the long term, recognizing it will make the need to decarbonize electricity even more acute.

Adam: Writing for the Institute, the Natural Resource Defense Council’s CCS expert, George Peridas, recently summarized California’s progress as “not a whole lot of progress on the CCS front to showcase since last year, but developments are expected soon”. How could the state reorder its CCS priorities to pick up the pace of technology development?

Jane: The state could get behind a demonstration project for a combined cycle gas plant. There are a lot of people skeptical about CCS. We need to have a concrete example that it works. A big issue in CCS is integrating all the complex industrial processes: electricity generation, capture, and storage. We need experience in actually doing what we theoretically ‘know’ how to do.

For an exploration of the broader report, along with further details on the technicalities of the model used in Jane’s analysis, check out Andy Revkin’s interview with Jane at his Dot Earth blog at the New York Times.