Among environmentalists, nuclear power belongs, together with genetic engineering and geo-engineering, to the group of the most dogmatically condemned technologies humanity ever has developed. There are exceptions from this paradigm, perhaps the most notable being the British environmental journalist Mark Lynas. But most members of the environmentalist movement hate the nuke, fearing the radiation, Chernobyl-like accidents, peak uranium, conflict with renewables, adverse environmental consequences of uranium mining, terrorist dangers and the like. However, when confronted with recent insights from climate science, one should ask: isn’t nuke the lesser evil?
When in 2006 the Stern Review of the Economics of Climate Change was published, an enormous debate emerged. Nonetheless, most of the discussion has been focused on economic-technical issues: discounting, damage function, treatment of uncertainty etc. Only few critics viewed the stabilisation goals (regarding the atmospheric concentrations of greenhouse gases to be aimed at) chosen by Stern as problematic. However, more recent findings from climate science suggest that here might be possibly the biggest flaw of Stern’s analysis.
The central value for greenhouse gas concentrations stabilisation in the Stern Review was 550 ppm CO2-e respectively about 450 ppm CO2. This was viewed as a “safe” target and, by the way, the lowest viable one. Since then, some climate scientists have suggested that this target may be far too high. Indeed, they name 350 ppm CO2 as what our long-term goal should be if we want to avoid catastrophic climate change due to the likely trespassing of tipping points that would uncontrollably accelerate global warming. The problematic fact is that we have left 350 ppm behind us as late as in the 80’s – and today the atmospheric concentration of carbon dioxide is approaching 400 ppm.
Nevertheless, there are strong arguments for embracing the 350 ppm target. One of its main advocates is NASA climatologist James Hansen. More than 3 years ago, he published a paper [pdf] in which he presented paleoclimatic evidence suggesting that for the climate system to “tip”, much lower long-run concentrations of greenhouse gases may be needed than previously thought. Therefore, he calls for a programme of steep reductions of CO2 emissions down to 0 in 2050, followed by negative emissions thereafter (e.g., from a combination of the CCS technology with biomass burning).
Moreover, Hansen’s cause is supported by research suggesting that so-called overshooting scenarios (as included in, inter alia, the Stern Review), where global mean temperature is projected to rise above a target and then relatively fastly fall below again due to harsh reductions in greenhouse gas emissions, are not viable – not at a relevant time scale at least.
What does this have to do with the discussion about nuclear power? Quite a lot, indeed. Many view it as highly unlikely that humanity would be able to stabilise greenhouse gas concentrations at any acceptable level (be it 350 ppm CO2, be it somewhat higher a target) relying on renewable energies only. However, the only known alternative to wind, solar, hydropower, geothermal and biomass/biofuels is nuclear power. It is therefore claimed that, even if we see nuke as “bad”, it may be less bad than the catastrophic climate change that will take place if we don’t stabilise greenhouse gas concentrations soon.
At this point we should try to answer the question: how bad is nuclear power really?
Even though some anti-nuclear arguments seem to be flawed, there are at least a few that are true with near certainty. First, and most prosaic – nuclear power plants have extremely high up-front costs. They are so high that it is unlikely in most countries that a private company would be able to bear them without support from public funds. On the other hand, once a nuclear power plant is built, its running costs are quite low, not least because they need very little fuel (a 1 GW unit needs some 30 tonnes of uranium per year). Furthermore, just as coal, gas and solar thermal plants, nuclear power stations need vast amounts of water for cooling, which is highly detrimental for aquatic ecosystems (as the heated water is then returned to the source) and may be a problem in more arid areas due to general water scarcity. As stated, this is a problem that nuclear shares with most conventional power generation methods and with what some believe to be its main alternative, viz. solar thermal (which additionally needs water for cleaning the mirrors). Another downside is the apparent conflict between nuclear power plants, which are as baseload as it goes (being very difficult to regulate in response to fluctuations in both energy demand and supply), and large-scale renewable energy generation (wind, solar etc.) that is highly fluctuating and unpredictable in the short-term. On the other hand, storage options for renewable electricity might alleviate this problem.
What with regard to the supposed environmental and health dangers of nuclear power? Here, the picture is somewhat unclear. It appears to me very likely that dangers of Chernobyl-like disasters or cancer in vicinity of the plants are rather overstated by those opposing nuclear power. To be clear: the danger that a nuclear power plant blows up is and will always be present, as shown impressively last year in Japan. However, most available evidence suggests that the consequences of the Daiichi accident have remained within limits. While what happened in Fukushima was a tragedy, more evil happens in other places due to disruptive human activities, without comparable attention from the public. Still, it has to be borne in mind that running nuclear power plants is inextricably linked to the danger of a serious accident.
Another point of concern is uranium mining. However, it is not much more destructive to the environment and does not pose much more health risks than any other kind of mining. The difference is that, as already pointed out, the need for uranium is rather limited (and the fuel can be recycled to some extent). The fact is: mining is generally bad for environment and being a miner is not quite healthy an occupation. But given how much our civilisation depends on mined products (be it metals, coal, oil, uranium or whatever else), mining apparently is worth the risks, at least in some cases.
The last problematic issue that I have to mention is final storage of highly radioactive waste. This issue remains highly controversial and I have not the expertise to judge who is right. The spectrum of opinions goes from those who see surface-disposal as sufficient, especially when combined with recycling of nuclear fuel, to those who see deep underground storage in geologically stable formations as the imperative. The fact is that so far, whether for political or technical reasons, there is no final storage site running (though the Finns plan to start running the Onkalo repository in 2020). The problem is still unsolved.
So, after having sketched the downsides of this technology: what speaks in favour of the nuke? Certainly more than most environmentalists would like. First of all, there is the urgent need to phase out fossil fuels if we want to keep anthropogenic climate change within safe limits. So far, we have not the renewable technology to complete the transition. In fact, what speaks against renewables, speaks in favour of nuclear, for it is the only low-carbon alternative we have to date. And the downsides of renewable energy generation are numerous:
- In the future, electricity demand is likely to increase for multiple reasons: population growth, rising prosperity (and thus access to and demand for electricity) in developing countries, the necessity to switch to electric surface transport (the use of biofuels should be, if anything, limited to aircraft for environmental and food-related reasons) etc. For the time being, 18 % of world electricity supply is from renewable sources (nuke provides 13 %). Even increasing at high rates, it is unlikely to rise fast enough to make possible a switch away from both fossil fuels <b>and</b> nuclear power. Especially given the other two major problems.
- Most renewable energies need very much space. In our crowded world, where pristine or even just intact habitats become ever more scarce, this is a very important argument. In most countries, the remaining capacity for hydropower (which has a relatively low footprint in terms of space need) is low – the main alternatives, wind and solar, being very space-consuming. Meanwhile, due to uranium’s very high energy density, nuclear power’s spatial footprint is rather low.
- The most important, still unresolved problem of renewable energy generation is storage. Households may be able to function with fluctuating wind or solar electricity and limited storage – but what about factories? Or, for that matter, any bigger coherent unit (e.g., a clinic)? They need some kind of baseload-like power. Without breakthroughs in this regard, we can likely forget about stopping climate change – with or without nuclear power. Since it is probable that the solution of this problem will take some more time, there is an urgent need for a “bridge technology”.
All this are reasons why most analysts include nuclear power in their projections of any programme of ambitious greenhouse gas emissions cuts, as shown in this meta-analysis [pdf]. Except environmentalist organisations, no one seems to believe that we are able to tackle climate change while at the same time tackling nuclear power. Quite the contrary.
As readers of this blog know, I am by no means a friend of the nuke. Even though I recently had to rethink some of the anti-nuclear arguments I previously had used, I still wouldn’t embrace nuclear power if I could imagine that we can save the world from catastrophic climate change without it. But I can’t. It may be that we, again, solve one problem while creating another (in the hope that the latter won’t be as serious). But if we fail to solve the former, the game will be over. It may well be that we haven’t left ourselves a choice.