Professor Sovacool has responded to this article in email messages to this site: see Discussion page
Benjamin K. Sovacool is director of the Danish Center for Energy Technology at the Department of Business Technology and Development and a professor of social sciences at Aarhus University. He is also professor of energy policy at the University of Sussex, where he directs both the Center on Innovation and Energy Demand, one of six End Use Energy Demand Centres in the United Kingdom, and the Sussex Energy Group. His research interests include energy policy, environmental issues, and science and technology policy. He is the author or editor of eighteen books and 300 peer-reviewed academic articles and chapters and has written opinion editorials for The Wall Street Journal and the San Francisco Chronicle. Sovacool is editor-in-chief of Energy Research & Social Science, which explores the interactions between energy systems and society.
-- From wikipedia
- 1 2008: Valuing the greenhouse gas emissions from nuclear power: A critical survey
- 2 2010: A Critical Evaluation of Nuclear Power and Renewable Electricity in Asia
- 3 2009: Bird mortality studies
- 4 2016: Nuclear energy and path dependence in Europe’s ‘Energy union’: coherence or continued divergence?
- 5 2020: Differences in carbon emissions reduction between countries pursuing renewable electricity versus nuclear power
- 6 Footnotes and references
2008: Valuing the greenhouse gas emissions from nuclear power: A critical survey
Arguably the most popular of Sovacool's papers on the Internet is Valuing the greenhouse gas emissions from nuclear power: A critical survey published in the journal Energy Policy in 2008. It is a survey of analyses done on this topic.
Sovacool found 103 papers estimating the greenhouse gas emissions for the nuclear fuel cycle. He then subjected them to a selection process which consisted of the following:
- He rejected 40 that were too old (published before 1997).
- He rejected 9 that were not published in English or were not open access, though this paper was not published as open access.
- He rejected 35 because of methodology. In most cases, this was due to relying either on unpublished data or on secondary sources (e.g. other analyses). Oddly, he also excluded a study that calculated very low emissions that relied on "published utility data", which did not appear to meet his criterion.
This left 19 studies which satisfied his criteria. He did not evaluate the soundness of studies' methodologies, or whether they were peer reviewed, just whether they contained enough detail. He also did not remove superseded versions of the same analysis from the same authors. This led him to include 3 versions of the StormSmith study, as well as 3 different studies by Dones et al. Finally, to arrive at a "true" value of CO
2 emissions, he calculated a mean of all results. He arrived at a value of 66 g/kWh, which he then compared to emissions from other sources, with each value selected from a single analysis.
This approach has several flaws:
- The criteria of the selection process are faulty, as it leads to the inclusion of the debunked "StormSmith" work, while rejecting studies based on real world measurements.
- The mean is used as the true value; however a mean is sensitive to outliers so a more accurate measure would be the median.
- The emissions for other sources are not obtained using the same process, and therefore not directly comparable.
A better meta-analysis which investigated a larger corpus of literature and additionally excluded studies using the average economic intensity (AEI) method, which is known to produce bogus results for projects utilizing lots of high-value, low-energy labor (such as the construction and operation of nuclear power plants), came up with a median of 13 g/kWh lifecycle emissions for light water reactors.
2010: A Critical Evaluation of Nuclear Power and Renewable Electricity in Asia
This publication makes many claims.
One uses Sovacool's "Valuing the greenhouse gas emissions from nuclear power" analysis to argue that renewable energy is "two to seven times more effective" at combating global warming than nuclear power, based on the values he cites for wind, at around 10 g/kWh, being around 6 times lower than those he calculates for nuclear energy. However nuclear energy displaces other base load power, mainly coal, whereas wind displaces mainly natural gas and hydro, since gas turbines and dams can vary output much more quickly to respond to wind's variability.
Even assuming that wind displaces only natural gas and not hydro, and taking from Sovacool's article figures for the emissions of coal and gas as 960 and 443 g/kWh respectively, then generating 1 kWh of nuclear electricity saves the need to generate 1 kWh from coal, saving 894 g of CO
2, whilst 1 kWh of wind displacing 1 kWh of gas saves 433 g of CO
2. Thus nuclear is at least twice as effective at reducing emissions. If the existing grid is almost 100% natural gas, as is the case in some Arab countries, then each kWh from nuclear would save 367 g, while each kWh from wind would save 433 g. In this rather extreme scenario, nuclear would be 15% less effective per kWh than wind.
Thus even Sovacool's own numbers do not support the claim that nuclear is "two to seven times less effective" at emissions reduction than renewable sources. Compounded with the fact that a later analysis produced a much lower number of 13 g/kWh, this contention is unsupported by evidence.
2009: Bird mortality studies
Sovacool's oft-cited 2009 paper Contextualizing avian mortality: A preliminary appraisal of bird and bat fatalities from wind, fossil-fuel, and nuclear electricity concluded that fossil fuel energy and nuclear energy causes 10 times more bird deaths per GWh generated than does wind energy. This paper had the unusual distinction of having a direct rebuttal of its conclusions (Willis et al. 2010) published in the same journal (a feature shared by fewer than 2% of peer-reviewed papers). Further studies by Sovacool in 2012 and 2013 reached conclusions similar to the 2009 paper.
In early 2013 Sovacool's studies were reported in the press and attracted criticism from some bloggesr, particularly regarding Sovacool's flawed methodology, which assigned deaths from fossil-fuel plants to nuclear power, deaths from copper mining to uranium, and assumed that unusual accidents were common occurrences. In response Sovacool acknowledged several errors which, if corrected, would have significantly changed his conclusions.
Perhaps the most notable failing of these papers is that Sovacool considers lifecycle bird deaths for nuclear, while omitting them for wind. Thus, the fact that wind uses 10 times more steel than nuclear and 700 times more copper than nuclear per MWh generated, would have reversed Sovacool's conclusions even if that were the only error in these papers.
2016: Nuclear energy and path dependence in Europe’s ‘Energy union’: coherence or continued divergence?
The paper Nuclear energy and path dependence in Europe’s ‘Energy union’: coherence or continued divergence? by Andrew Lawrence, Benjamin Sovacool & Andrew Stirling, published in Climate Policy on 1 July 2016, claimed according to its press release:
most progress towards reducing carbon emissions and increasing renewable energy sources – as set out in the EU's 2020 Strategy – has been made by [EU] nations without nuclear energy or with plans to reduce it
Critical responses to 2016 paper
In a post "Being pro-nuclear does not undermine climate and energy goals" on his "Climate Answers" website Stephen Tindale discusses Lawrence, Sovacool and Stirling's paper:
The authors consider data from all European countries. They divide them into three main categories: always anti-nuclear (13 countries); now anti-nuclear (7); pro-nuclear (8). The headline conclusions are that:
- The always-anti countries have reduced their emissions by an average of 6% since 2005, and had increased renewable energy sources to 26%.
- The now-anti countries reduced emissions on average by 11% while expanding renewables to 19%.
- In pro-nuclear countries, greenhouse gas emissions have increased since 2005 by an average of 3%, and only 16% of energy is from renewables.
- “[The] intensities of national commitment to nuclear power tend to be inversely related to degrees of success in achieving EU climate policy goals.”
The study was published in the journal Climate Policy, so will have been peer reviewed. It deserves to be taken seriously – and has already been widely discussed. However, the authors’ conclusions are, in our view, based on two significant mistakes:
- The categories of pro- and anti-nuclear are too broad and do not compare like with like;
- Reduction of greenhouse gases and promotion of renewable energy are presented together as a single objective. They are not.
The authors group countries together into always anti-nuclear, now anti-nuclear and pro-nuclear. To be in the ‘now anti-‘ category, a country’s government must have a policy to decommission existing nuclear power stations and not allow replacements. Germany clearly belongs in this category. Does Sweden, which the authors also place there? In 1980 Swedes voted in a referendum to phase out nuclear power, though no timetable was set. Since then Swedish policy on nuclear has been, to use the diplomatic word used by the World Nuclear Association, “ambivalent”. In 2010, at the behest of a centre-right government, the Swedish parliament lifted the ban on new nuclear construction. In 2014 the Green Party entered a centre-left coalition, so new nuclear was off the political agenda for a while. But on 10 June this year (so shortly after the publication of the Climate Policy article) the government lifted its moratorium on nuclear new build, and also reduced the tax on nuclear. Sweden is not, therefore, an anti-nuclear country.
The countries which the authors do place in their pro-nuclear category are Finland, Hungary, Poland, Slovakia and the UK: countries with very different economic and political circumstances. We do not believe that it makes analytical sense to compare western European countries – established democracies with strong economies – with ex-communist central and eastern European ones. And the existing energy mix is also a determining factor in a country’s attitude to climate action. The reason the Polish government opposes strong greenhouse gas reduction targets is not because it wants to build a nuclear power station; it is because Polish society and economy are currently so dependent on coal.
If one narrows the category to western European countries, how do pro-and anti-nuclear countries compare? In terms of greenhouse gas reductions since 2005, the figures given in the Climate Policy article are:
See article for table
Denmark and Ireland, the countries that have reduced emissions most since 2005, have always been anti-nuclear. But two examples do not constitute a proven link. Beyond these two, the figures do not establish correlation, let alone causation. In joint second on -16% are one country from each of the three categories. Anti-nuclear Germany and pro-nuclear Britain and France have each reduced emissions by 14% since 2005.
Performance on renewable energy
The authors then consider how well countries are performing on renewable energy. They mention the drawbacks of some renewable energy technologies, including large hydro and bioenergy, but nevertheless present single figures, covering all renewables, for each country. Bioenergy and nuclear can be used anywhere, but other renewables, especially hydro, are geographically dependent.
The figures for western European countries are given below. Again, there is no correlation between attitude to nuclear and performance on renewables.
See article for table
Sweden get about 40% of its electricity from hydro; Finland 18%. Finland got 16% of electricity from bioenergy in 2013, Sweden 6%. Both countries also use bioenergy extensively for heating. They have strong criteria for minimising the biodiversity impact of biomass, but not for assessing the carbon footprint. EU rules on the carbon footprint of bioenergy apply only to biofuels, not to biomass. Bioenergy is necessary, particularly for heating and for transport. But not all bioenergy expansion is desirable. Being renewable is not the same as being good for the climate. Similarly, large-scale hydro, has some severe consequences to habitats, erosion and hydrology meaning though it is good for the climate, it is not necessarily good for the environment.
Are renewables better than nuclear?
Does it matter whether greenhouse gas reductions are achieved through expansion of renewables, or through other measures? It does not matter to the global climate. In our view, the scale of the climate crisis is such that we need rapidly to move beyond arguments about which low-carbon technology to support and accepted that all are required. (Our next report will be on this issue.) But the way in which emissions are reduced appears to matter to the Climate Policy authors. Professor Andy Stirling, said about his report: “By suppressing better ways to meet climate goals, evidence suggests entrenched commitments to nuclear power may actually be counterproductive.”
Academics should always define their terms. So we have a question for Professor Sterling: better in what sense?
A response by Nicholas Thompson criticised the paper for its mathematical methods - the arithmetic of calculating percentages, and how to calculate averages for a group of countries, the paper's choice of start- and end-points, the lack of statistical significance of having a group comprising only two members, and its failure to take account of population sizes of countries studied. Correcting for these errors Thompson found that:
None of [the paper's] data seem to support [its] conclusions, and the entire paper is based on those conclusions. If anything, countries with nuclear energy tend to have started with lower emissions per capita, and achieved more emissions reductions in percentage terms.
Nuclear Pretty Please
The paper was retracted by the authors in November 2016.
An article in Retraction Watch "Authors retract paper linking nuclear power to slow action on climate change" (apparently dated 28 Nov 2016) reports:
Do pro-nuclear energy countries act more slowly to curb the effects of climate change? That’s what a paper published in July in the journal Climate Policy claimed. But the hotly debated study was retracted last week after the authors came to understand that it included serious errors.
- While it’s difficult to show a causal link, the researchers say the study casts significant doubts on nuclear energy as the answer to combating climate change.
But there were two errors in the paper, “Nuclear energy and path dependence in Europe’s ‘Energy union’: coherence or continued divergence?” The first, co-author Andrew Stirling of the University of Sussex told Retraction Watch, was in data transcription, and was brought to the authors’ attention by a post on Nuclear Pretty Please.
That led to a correction. But, as Stirling noted, his analysis :
- …illuminated the separate time series baseline mistake. This had also been picked up by another blogger, called Nick Thomson.
Thomson lists a host of concerns about the paper, including the math and methodology, and argues that the data don’t support the authors’ main conclusion that countries which embrace nuclear energy are slower to meet climate goals.
Stirling and his co-authors — Andrew Lawrence, of the Vienna School of International Studies, and Benjamin Sovacool, also at the University of Sussex — submitted a response to that blog, Stirling said, but it has yet to be posted.
What’s more, another post by Stephen Tindale and Suzanna Hinson, blogging at Weinberg Next Nuclear on August 26 noted two issues:
- – The categories of pro- and anti-nuclear are too broad and do not compare like with like;
- – Reduction of greenhouse gases and promotion of renewable energy are presented together as a single objective. They are not.
Then, on November 25, the paper was retracted. The notice — which is quite detailed, and was agreed upon by all three authors, according to Stirling — begins:
- It is with great regret that we, the authors, have withdrawn this article from publication in Climate Policy.
- The grounds for this are that it has come to our attention that two serious errors were committed by the first author (AL) on this paper. The second (BS) and third (AS) authors entirely failed to identify and correct these errors prior to publication. Of course, all three authors share joint responsibility for this paper, and apologize to readers of Climate Policy for our omission of oversight.
- Together, the errors have the effect of invalidating this particular analysis concerning the relative performance of nuclear-committed European countries in wider climate change.
Although the press release has subsequently been removed from the University of Sussex website, it was published by 'The Ecologist' as an article with a note acknowledging the retraction inserted with little prominence within the article text:
Editor's note: On 25th November 2016 the authors retracted the paper on which this article is based citing "two serious errors by one of the authors". They intend to resubmit after making corrections.
2020: Differences in carbon emissions reduction between countries pursuing renewable electricity versus nuclear power
In a paper "Differences in carbon emissions reduction between countries pursuing renewable electricity versus nuclear power" published in Nature Energy on 5th October 2020, Sovacool, Patrick Schmid, Andy Stirling, Goetz Walter & Gordon MacKerron claim:
Two of the most widely emphasized contenders for carbon emissions reduction in the electricity sector are nuclear power and renewable energy. While scenarios regularly question the potential impacts of adoption of various technology mixes in the future, it is less clear which technology has been associated with greater historical emission reductions. Here, we use multiple regression analyses on global datasets of national carbon emissions and renewable and nuclear electricity production across 123 countries over 25 years to examine systematically patterns in how countries variously using nuclear power and renewables contrastingly show higher or lower carbon emissions. We find that larger-scale national nuclear attachments do not tend to associate with significantly lower carbon emissions while renewables do. We also find a negative association between the scales of national nuclear and renewables attachments. This suggests nuclear and renewables attachments tend to crowd each other out.
The University of Sussex' press release accompanying the paper claims:
Two's a crowd: Nuclear and renewables don't mix. Only the latter can deliver truly low carbon energy says new study
If countries want to lower emissions as substantially, rapidly and cost-effectively as possible, they should prioritize support for renewables, rather than nuclear power.
That’s the finding of new analysis of 123 countries over 25 years by the University of Sussex Business School and the ISM International School of Management which reveals that nuclear energy programmes around the world tend not to deliver sufficient carbon emission reductions and so should not be considered an effective low carbon energy source.
Researchers found that unlike renewables, countries around the world with larger scale national nuclear attachments do not tend to show significantly lower carbon emissions - and in poorer countries nuclear programmes actually tend to associate with relatively higher emissions.
Published today in Nature Energy, the study reveals that nuclear and renewable energy programmes do not tend to co-exist well together in national low-carbon energy systems but instead crowd each other out and limit effectiveness.
The press release has been picked up and churned into an article in TechExplore: "Two's a crowd: Nuclear and renewables don't mix" and reworked into a piece in New Scientist: "Countries that backed renewables over nuclear power have cut more CO2" by Adam Vaughan [paywalled].
Sovacool has also published a blog piece as a supplement to his paper: "The sustainability of nuclear power and the critical importance of independent research" (Benjamin Sovacool, Andy Stirling; Nature; 5 Oct 2020).
A portion of the blog piece discusses the retracted 2016 paper, emphasising Sovacool and Stirling's roles as merely secondary authors of the now-retracted paper and the "open, rigorous and professional way" in which they handled the retraction.
Critical responses to 2020 paper
In an article "Natürlich verringert Kernenergie den CO₂-Ausstoß!" on the Nuklearia blog on 10 Oct 2020, Martin Knipfer writes (in German; Google translation follows)
Nuclear energy naturally reduces CO₂ emissions!
Published on 2020-10-10 by Martin Knipfer
A recently published study by Benjamin K. Sovacool suggests that a higher proportion of nuclear energy does not lead to a reduction in CO₂. This is nonsense because the work uses a totally unsuitable parameter for comparison.
Benjamin K. Sovacool is no stranger to the nuclear energy debate. Several studies by the professor of energy policy on the accident risk of various energy sources or the CO₂ emissions per kilowatt hour have already attracted the attention of opponents and supporters of the technology in the past. The most recent publication, entitled “Differences in carbon emissions reduction between countries pursuing renewable electricity versus nuclear power” in the journal Nature Energy , offers a lot of explosive material: In addition to the usual negative framing of nuclear energy, it has an extremely serious methodological flaw on.
One thesis in particular attracted particular media attention: the use of nuclear energy does not contribute to lower CO₂ emissions. In contrast, this is already the case with renewable energies.
Secured versus unsecured renewable energies
An important preliminary remark: Renewable energies not only include solar and wind energy, but also hydropower . In some parts of the world, electricity is largely CO₂-free because hydropower plants form the stable backbone of the supply. In many places, however, this energy source can only be expanded to a very limited extent. What a country like Germany lacks in terms of hydropower cannot simply be replaced by wind and solar energy. Because if there is not enough wind and the sun is not shining, fossil-fuel power plants often have to be used as a backup today - a CO
2-intensive practice. This can be done in real time, for example, in the ElectricityMap. Therefore it is at least questionable to group secured hydropower and variable solar and wind power in the same category for the analysis.
Rich countries have higher emissions - not because of, but in spite of nuclear power
But much more important: the study does not even allow the conclusion that nuclear energy has no influence on CO₂ emissions.
The analysis by Sovacool et al. examines the statistical relationship between the share of nuclear energy and CO₂ emissions per capita in a country. However, the CO
2 emissions per capita is an unsuitable measure for this because the electricity sector only accounts for around 25% of total CO
2 emissions worldwide . It is therefore possible that a state has successfully reduced emissions in the electricity sector thanks to nuclear energy, but that the residents, for example, fly excessively by plane. Another context (namely economic power) "superimposes" the result. This phenomenon is referred to in statistics as a confounder .
There is a simple solution to circumvent this problem: Instead of CO₂ emissions per capita, the decisive factor is how CO
2-intensive one kilowatt-hour of electricity is generated. This variable has the advantage that the result is independent of the remaining energy consumption. And then a completely different picture emerges, as Diagram 1 shows: the higher the share of nuclear energy, the more climate-friendly the electricity in a country.
Poor countries have low emissions - and hydropower
But why, according to the study, is there a connection between the share of renewable energies and CO
2 emissions per capita? The reason for this can also be found in the economic power confounder, which overlays everything. Many developing countries whose CO
2 emissions are naturally very low are included in the statistics . The Democratic Republic of the Congo, for example, with 99.9% hydropower, has a phenomenally low 0.026 tonnes of CO
2 per capita, according to the World Bank. However, this is primarily due to the rampant poverty.
The authors anticipated criticism of their approach and justified the choice of CO
2 emissions per capita as follows:
“… Some may question a focus on national carbon emissions rather than looking at subsectors or emissions reductions. However, national-level emissions give more complete pictures of trends and accord better with this key locus of policymaking.”
»... some may question a focus on national CO
2 emissions instead of looking at sub-sectors or emissions reductions. However, emissions at the national level provide a more complete picture of trends and better reflect this central focus of policy making. «
However, this argument does not hold up . In the energy system of the future, the electricity sector will play a key role when electric cars need to be charged, green hydrogen is in demand and heated with heat pumps. It is crucial that every kilowatt hour of electricity is generated as cleanly as possible. A sole focus on CO
2 emissions per capita, on the other hand, would lead to the wrong conclusion that an energy system like the one in the Democratic Republic of the Congo is desirable for the whole world.
- Differences in carbon emissions reduction between countries pursuing renewable electricity versus nuclear power ; Nature Energy; Sovacool, BK, Schmid, P., Stirling, A., Walter, G., MacKerron, G .; 2020-10-05
- AR5 Climate Change 2014: Mitigation of Climate Change ; IPCC; 2014
2 emissions (metric tons per capita) - Congo, Dem. Rep .; World Bank
- We Need Both Nuclear and Renewables to Protect the Climate ; Alex Gilbert; The Breakthrough Institute; 2020-10-08
Martin Knipfer studies geoinformatics in Munich. He previously worked for an energy research institute.
Nuclear Innovation Alliance
A blog post "We Need Both Nuclear and Renewables to Protect the Climate" on the Nuclear Innovation Alliance website makes several criticisms of Sovacool et. al. including that:
the study is evaluating whether an electricity source decarbonizes a nation by correlating its presence or absence to per capita greenhouse gas emissions from multiple sectors – i.e, including not just electricity but also industry and other sectors.
The choice of that simplistic metric skews the results. Currently, most countries with existing nuclear power are industrialized and have large non-electric CO2 emissions – because people in rich nations consume more energy per capita in industry and buildings than people in poor nations because they live in bigger houses and manufacture more things.
The study then compares per capita CO2 emissions in these rich nations with per capita emissions in many countries consuming low levels of energy that primarily get their electricity from hydropower. Although the authors’ discussion infers that renewables are better due to the distributed nature of wind and solar, the primary renewable during the time period examined (1990-2014) was in fact hydropower (comprising 85% of total renewable supply). Hence, the study is only finding that most countries with large amounts of hydropower have low emissions, which is primarily because they are poor and do not have significant non-electric emissions, not because renewables are better for decarbonization. In effect, the study is picking up that many countries suffering from energy poverty have low carbon emissions.
Sovacool's co-author Andy Stirling responded to the NIA's criticisms in a (somewhat verbose) comment on the blog of the Sussex Energy Group, of which Sovacool is director.
The paper has been criticised by Alex Gilbert (@gilbeaq):
A new article by Sovacool et. al. in Nature Energy claims nuclear energy is not associated with lowering GHG emissions while renewables are.
The article's analysis does not support this contention but rather reflects the dynamics of global energy poverty
To start, the authors admit that their study is correlation and not indicative of causation.
However, they then base their analysis and conclusions on the inference of causation. Such logical leaps should not have made it past peer review. Here's why:
At the core the article just does a regression of non-transportation CO2 emissions per capita versus nuclear and renewable energy use.
This is immediately suspect as nuclear and renewables are primarily for the electric sector
In effect, what this choice means is that their selection criteria is comparing the 30 countries with nuclear power with most countries in the world.
Countries with nuclear power are more likely to be wealthy and industrialized, and hence have higher non-power CO2 emissions
Despite discussing wind and solar as renewables and making inferences about causation, the primary renewable in their data sets (1995-2004 and 2005-2014) is hydropower.
Hydropower is as centralized and prone to cost isssues as nuclear, invalidating most of their inferences
Most countries have hydropower as it is a primary tool of electrification and supported by development banks (notably, nuclear is not).
Hence their dataset starts with 30 countries with higher than average CO2 emissions per capita...
And compares them with ~120 countries that include many countries with low CO2 emissions per capita due to general poverty and energy poverty.
As energy poor countries do not have industrial emissions and only have hydro, their regression appears to show renewables are better
All it really shows is that energy poverty and not having industrial emissions means you do not have large CO2 emissions. That is not ground breaking and it does nothing to contribute to an analysis of comparative merits of different energy resources That is the fundamental flaw with this analysis. It does not take into account the energy situations of most countries. It conflates hydropower with all renewables. It then claims that there is a tension b/n choosing the two, again based on simple regression
Like all renewables, hydro resources are constrained. Not all countries have them. France is a notable example - with limited alternatives it pursued nuclear for an energy security strategy. In this study, that choice contributes to a conclusion that nuclear crowds out renewables Here is what the body of peer-reviewed literature and energy policy expertise really show:
Nuclear and renewables are carbon-free
Both have a role to play in decarbonization
Neither is being used at sufficient rates to displace fossil fuels
The data in the study does lead to an improtant insight: most nuclear power countries are wealthy and industrialized and nuclear is not an energy option for most developing nations.
We can change that with new technologies and by enabling development banks to fund nuclear
Jesse Jenkins also urges caution, and scepticism:
I'd love to have someone well versed in causal inference take a look at this, but I'm extremely skeptical this kind of inference is even possible given huge set of confounders. I tried something like this long ago & gave up myself. Any social scientists want to hop in here?
I mean the idea that either nuclear energy or renewable energy has NO effect on emissions is pretty spurious. It is easy to design a poor inference setup that fails to produce statistically significant estimates not because there is no causality but because your method is bad.
That said, this passed some kind of peer review, so w/o spending more time than I have now, I cant say whether they address concerns or not. But whenever you get a statistical inference that conflicts with common sense undestranding of causal mechanisms, one should be skeptical.
Ken Caldiera observes that his plots of Sovacool's data show the opposite of what Sovacool claims:
A recent article by Sovacool shows a better correlation between use of renewables and low emissions per capita than between use of nuclear and low emissions.
Now what bothers me is that this new paper seems really interesting to me after a quick read, but everyone is misinterpreting the results! So here are some clarifications...
No, the paper does not show that renewables emit less GHG than nuclear power. LCA tends to show that emissions per kwh are on the same scale, or slightly lower for nuclear than for wind or solar.
No, the paper does not show that adopting a renewable strategy in your country will lead to lower emissions than adopting a nuclear strategy. Right now in Europe the grid cannot support a large share of diffuse, non-adaptable sources like wind/solar.
What the paper shows is that, as a whole, countries using renewables have lower emissions per capita in the last 30y than countries using nuclear, corrected for gdp. This raises several important questions.
1) Are there side effects of adopting either technology that explain the difference? (E.g. more heavy industry in nuclear countries) It's possible that a nuclear plant on its own shows low emissions while the broad adoption of a nuclear strategy leads to higher emissions overall.
2) Could the difference be explained by the starting year? Sovacool starts his analysis in 1990 but the nuclear transition in e.g France started in the late seventies.
3) Is there indeed a crowding out effect? The paper suggests that in some but not all cases, the adoption of one strategy might have excluded the other. Can we have nuclear AND renewable, and if not, why can't we? (No causal link in the paper) We desperately need a rational discussion about this. The issue is extremely polarized. No time for biased reporting and insults! I hope this will result in fruitful discussions.
It has also been pointed out that Sovacool et al's selection of the study period, from 1990-2014, excluded the successful decarbonisation of France and Sweden in 1970s-1980s.
Footnotes and references
- Many articles on RationalWiki's site are presented in an opinionated, scathing, and sometimes sarcastic manner, whilst Science for Sustainability attempts to maintain a neutral point of view and tone. For this reason RationalWiki's article has been paraphrased rather than quoted verbatim.
- Quote: "These studies were "weighed" equally; that is, they were not adjusted in particular for their methodology, time of release within the past 10 years, or how rigorously they were peer reviewed or cited in the literature."
- Ethan S. Warner, Garvin A. Heath, Life Cycle Greenhouse Gas Emissions of Nuclear Electricity Generation, Journal of Industrial Ecology 2012, 16(s1), pp. S73-S92
- A Critical Evaluation of Nuclear Power and Renewable Electricity in Asia Benjamin K. Sovacool; Journal of Contemporary Asia; 15 Jun 2010
- Benjamin K. Sovacool, A Critical Evaluation of Nuclear Power and Renewable Electricity in Asia, Journal of Contemporary Asia, 2010, 40(3), pp. 369-400
- Pacific Winds: The health and climate benefits of Altamont Pass wind power: "The clean, renewable power generation from the Altamont wind farms displaces natural gas generation..."
- American Wind Energy Association: Wind energy driving down consumer electric rates: "Since wind energy primarily displaces natural gas generated energy, reducing the quantity of natural gas purchases..."
- "Energy intensities, EROIs (energy returned on invested), and energy payback times of electricity generating power plants." Weißbach, D., et al. , Energy 52 (2013): 210-221.
- The ClimateAnswers.info domain name has apparently lapsed since Stephen's death and been taken over by an unconnected organisation.
- A Response to Lawrence, Sovacool, and Stirling by Nicholas Thompson; 12 Oct 2016
- Authorial statement of article withdrawal, Andrew Lawrence, Benjamin Sovacool & Andrew Stirling, Taylor & Francis online, 25 Nov 2016
- The Weinberg Next Nuclear domain the-weinberg-foundation.org no longer contains its original content and there is no copy on the Internet Archive Wayback Machine
- New study suggests pro-nuclear countries are making much slower progress on climate targets James Hakner; The Ecologist; 24 Aug 2016
- Nature Energy unpaywalled full paper (PDF) supplementary material (PDF)
- The NIA blog post is unsigned but the NIA staff includes Alex Gilbert who earlier posted similar criticisms on Twitter