Nuclear for 1.5°C

Hope and Fantasy in Equal Measure

Last week, the Intergovernmental Panel on Climate Change (IPCC) released a major report on pathways to limiting climate change to 1.5 degrees Celsius over pre-industrial levels. The report is mostly a modeling exercise, as the 1.5° target is significantly more ambitious than most analysts consider feasible. The Paris Agreement formalized an international commitment to limiting warming to 2°, and even achieving that target may prove impossible. Nonetheless, IPCC reports deserve at least some attention, as they reflect the international scientific consensus around climate change.

Predictably, reactions to the report varied widely. Some offered warnings of the risk of crises after reaching 1.5°C warming, while others advocated for the end of capitalism in order to limit climate change. Nuclear advocates were mixed too: some saw the IPCC report as evidence of bias against nuclear power.

But we see the IPCC's assessment of nuclear as half full, not half empty. In the past, the UN and the IPCC have been reluctant to recognize that nuclear could have a role in mitigating climate change at all. But the new report clearly states that “nuclear power increases its share [of world energy] in most 1.5°C pathways by 2050.” Nuclear has a particularly strong role in pathways in which the world has higher economic growth and energy demand. Notably, in every 1.5° pathway, global investment per year in nuclear exceeds global investment in solar between 2016 and 2050.

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Nuclear increases substantially in every illustrative 1.5° pathway. P1 represents the 1.5° pathway with the least economic and energy growth; P4 the most. Nuclear’s share of primary energy doubles by 2030 and quintuples by 2050 in the scenarios with the highest economic growth and energy demand. (Source: IPCC report, p. SPM-19.)

The report also compares nuclear with other low-carbon generation technologies, like wind, solar, bioenergy, and carbon capture. The IPCC finds that each technology — not just nuclear — faces significant barriers to feasibility in achieving 1.5° C. For example, the report notes that wind, solar, and biomass each require extensive land use change and materials inputs, while nuclear and CCS do not. However, nuclear faces significant barriers in governance and social acceptance. Even the most strident nuclear advocates admit that fear and distrust are still substantial barriers to widespread adoption of nuclear. Remarkably, the report found that all other options for decarbonizing electricity (except solar) have similar economic barriers to adoption as nuclear.

It’s also crucial to remember that the IPCC merely seeks to reflect the state of the academic literature. Insofar as the IPCC’s assessment is pessimistic about the role that nuclear energy will need to play in future decarbonization efforts, that is a reflection of biases in the peer-reviewed literature, not the assessment itself. The assessment is mixed because the literature is mixed.

And clearly, whatever issues one may have with the underlying literature, nuclear continues to face significant obstacles. The report correctly reflects that many countries, particularly in the developing world, don't currently have the institutional capacity to support a rapid nuclear build-out. It also notes that nuclear faces acute challenges in liberalized economies and restructured electricity markets, particularly in the developed world. We may regret these challenges, but few deny them.

More broadly, the entire exercise has an angels-on-a-pinhead quality. It is constructed around a 1.5°C target that almost no one actually believes to be feasible. The more interesting questions for nuclear are not what role it will play in a 1.5°C world, but what role it will play in a 2.5° or 3°C world, where decarbonization occurs more incrementally, unevenly, and over a longer time horizon.

In short, the report is evidence that getting serious about climate change — more serious than any government ever has — would almost certainly involve building significantly more nuclear power. This is no surprise to those of us who have long argued that nuclear will be a necessary part of any serious effort to address the problem, but it has historically been resisted by many climate and environmental advocates.

The latest assessment makes it even harder to maintain that position and be taken seriously. It is also a clear rebuke to governments like Germany, which have loudly demanded climate action while seeking to minimize or eliminate nuclear power at the same time. This has turned out to be disastrous for Germany, which will likely miss its Paris targets that were designed to limit warning to 2°C. After this IPCC report, we can only hope that other countries will not make the same mistake.

Jameson breaks it down: