I’ve written frequently in this blog about the potential of natural gas to provide a bridge to a renewable energy future. I’ve been influenced by an important study from The Worldwatch Institute that suggests that a shift from coal to gas could make renewable deployment easier because gas-fired electricity generation – in addition to cutting carbon emissions in half and improving public health from reduced toxic air emissions – is flexible. That attribute can help the power grid accommodate renewables by smoothing out the load gaps created when the sun doesn’t shine or wind doesn’t blow. Indeed, the National Renewable Energy Laboratory’s model of 80% renewable energy generation relies on gas for the remaining 20%. I will add, however, that there is one study that suggests that the electric system can be powered 90%–99.9% of the time entirely by renewable electricity with deployment of advanced storage technologies and an overbuild in renewable capacity.
The gas-as-bridge concept has been attacked by opponents of shale gas development who argue, among other things, that cheap gas could displace renewables, though the evidence for that happening in the real world is lacking, particularly regarding booming solar power. They also inflate the impact of methane emissions from gas production. Elsewhere, progress on carbon capture and storage technology, which could transform natural gas to a near zero emissions power source, remains stunted and stalled. And of course, the renewable-supporting properties of gas-fired power will not provide their benefit unless they’re backed up by the right energy policies that drive the transition.
Michael Levi of the Council on Foreign Relations has a powerful new paper on natural gas as a bridge fuel. Levi focuses on climate targets – the frequently discussed targets of stabilizing atmospheric carbon at 350 parts per million (ppm), 450 ppm, or 550 ppm. Each target is associated with progressively more severe levels of warming - and we’ve already exceeded 350 ppm. Levi says that concern over methane emissions is misplaced, as they have only short-term impacts compared to CO2. His central finding is that natural gas doesn’t much help to achieve targets lower than 450 ppm.
So if gas can’t get us to 350 ppm, why push it at all? Is it a bridge to nowhere?
An analysis of the paper issued by Resources for the Future discusses the difficulty of reaching lower climate targets, and the likelihood – or impossibility - of succeeding in an “all-in bet” on renewables that gets us to 350 ppm by bypassing coal and gas and completely transforming the energy sector. Given the complexities, the politics – and the odds - of reaching that transformative goal, moving from coal to gas may best be viewed not as a bridge but as a hedge that will soften the coming climate blows.
Whether bridge or hedge, we must improve our odds of avoiding climate catastrophe. We must be smart with new gas resources. We must get the rules of natural gas production right. We must substitute gas for higher carbon sources of energy wherever possible. We must be much more aggressive in supporting renewables and driving their deployment. We must drive the deployment of CCS. We must enact smart regulation and establish a carbon price. We must do it all. Now.
Time is running out.