I set out here the climate change problem and the role of nuclear power, or nuclear energy, in addressing that problem. My argument is that nuclear power (with renewable energy) is an important option for achieving electricity production with a small carbon footprint – for reducing emissions. As a report from the Massachusetts Institute of Technology (MIT) in 2009 makes clear,
“the motivation to make more use of nuclear power is greater [than ever], and more rapid progress is needed in enabling the option of nuclear power expansion to play a role in meeting the global warming challenge. The sober warning is that if more is not done, nuclear power will diminish as a practical and timely option for deployment at a scale that would constitute a material contribution to climate change risk mitigation.”
The climate change problem: ‘How rapidly can we cut carbon emissions if civilisation is at stake?’
In explaining the science of climate change, the Australian National University’s Professor Andrew Glikson – an earth and paleo-climate scientist – states that the recent history of the atmosphere, which includes human-induced global warming, may lead toward mass extinction of species: On a ‘business-as-usual scenario,’ continuation of greenhouse gas emissions ‘will result in global warming of 3°C over the 21st century, eliminating a majority (60%) of species on the planet.’ He asks whether the human species is leading the biosphere to its sixth mass extinction.
A US study by MIT finds that, absent policy action, also on a business-as-usual course, the median probability of surface warming is 5.2°C by 2100, with a 90% probability range of 3.5 to 7.4 degrees, compared to a median projected increase in an earlier 2003 MIT study of just 2.4 degrees – that is, twice as severe.
And while there is no international consensus on what levels of climate change might be defined as ‘dangerous,’ there is widespread support for containing the rise in global temperature to 2°C above pre-industrial levels (known as the ‘2°C guardrail’); parties to the United Nations Framework Convention on Climate Change (UNFCCC) have adopted this global warming limit, with some of the most vulnerable states – small island states, for example – calling for temperature targets as low as 1.5°C. Even with temperature rises of less than 2°C, however, impacts can be significant, and beyond 2°C, ‘the possibilities for adaptation of society and ecosystems rapidly decline …’
The urgency of all this is further reinforced by a study by Meinshausen and others which finds that GHG emissions must be cut by more than 50% by 2050 as against 1990 levels if the danger of exceeding 2°C is to be limited to 25%. Meinshausen has said that
“[i]n principle, it is the sum of all CO2 that matters. In practice, substantial reductions in global emissions have to begin soon, before 2020. If we wait any longer, the required phase-out of carbon emissions will involve tremendous economic costs and technological challenges – miles beyond what can be considered politically feasible today. The longer we wait, the more likely our path will lead us into dangerous territory.”
For the Royal Society, sufficient climate change mitigation actions might well not be introduced in time:
“It is likely that global warming will exceed 2°C this century unless global greenhouse gas emissions are cut by at least 50% of 1990 levels by 2050, and by more thereafter. There is no credible emissions scenario under which global mean temperature would peak and then start to decline by 2100. Unless future efforts to reduce greenhouse gas emissions are much more successful then they have been so far, additional action may be required should it become necessary to cool the Earth this century.”
Such additional action according to the Royal Society might involve geoengineering – deliberate, large-scale intervention in the Earth’s climate system ‘in order to moderate global warming.’ And ‘geoengineering’ in the form of techniques for extracting atmospheric CO2 has also been considered by Hans Joachim Schellnhuber who, in the course of reviewing an article by Ramanathan and Feng in the Proceedings of the National Academy of Sciences – in which they suggest that the earth is already committed to anthropogenic warming in the range of 1.4-4.3°C (where 2.4°C is the most likely amount) and that no conceivable international strategy can avoid largely unmanageable climate impacts – says that
“[m]y conclusion is that we are still left with a fair chance to hold the 2°C line, yet the race between climate dynamics and climate policy will be a close one … However, the quintessential challenges remain, namely bending down the global Kyoto-GHG output curve in the 2015–2020 window (further procrastination would render necessary reduction gradients too steep thereafter) and phasing out carbon dioxide emissions completely by 2100. This requires an industrial revolution for sustainability starting now.”
Finally, the importance of early (or shorter-term) reductions is made by Parry and his colleagues:
“[W]e now have the knowledge to make a more informed choice regarding the optimal balance between mitigation and adaptation, and we know that immediate investment in adaptation will be essential to buffer the worst impacts. This does not mean that mitigation can be delayed, but quite the opposite: the longer we delay mitigation, the more likely it is that global change will exceed our capacity to adapt.”
As Gwynne Dyer asks, ‘how rapidly can we cut emissions if civilisation is at stake?’ And it’s that question, and the need to mitigate, which puts into context any examination of the role of nuclear power in cutting emissions.
This post (with footnotes omitted) is based on a paper delivered last week in Perth at the Australian Uranium Conference. Please contact the author for details of sources cited.
A second post by the same author, forthcoming here shortly, will expand on this theme and will specify how nuclear power can help address climate change. This post, in turn, will be followed by one or more “counterpoint” posts.