Greene,O., Percival,I. and Ridge,I. (1985) Nuclear Winter. Oxford: Polity Press. 252pp.

This essay continues my series of monthly posts in which I select one ‘climate’ book to highlight and review from one of the 44 years of my professional career in climate research (starting with 1984, my first year of academic employment).  The series will end in September 2027, the month in which I shall retire.  See here for more information about the rational for this series, and the criteria I have used in selecting my highlighted books.

This 1985 essay can be download as a pdf.

The early 1980s saw heightened tensions between the USA and the Soviet Union concerning the  possibility of nuclear war, fuelled in part by suspicions about the new American President’s – Ronald Reagan’s – Strategic Defence Initiative.  This Initiative, frequently referred to in the liberal media as ‘the Star Wars Programme’, was framed as a defensive move by Reagan, but was regarded by Soviet strategists at the time as a provocation to the existing nuclear weapons’ equilibrium.

Against this background of nuclear geopolitics, early in 1982 atmospheric scientists Paul Crutzen and John Birks published an article in Ambio[1], the journal of the Royal Swedish Academy of Sciences, which raised the stakes of a possible exchange of nuclear warheads between the two global superpowers.  Crutzen and Birks drew attention to an environmental consequence of such a conflagration that had not previously been attended to: the possibility of a sustained cooling of the Northern Hemisphere as a result of the large amount of particulate matter injected into the atmosphere due to the many fires that would be started in cities, forests, agricultural fields and oil and gas fields.  This darkness, the authors claimed, would disrupt climatic systems and

“…would persist for as long as the fires burn, which is expected to be many weeks. The screening of sunlight by the fire-produced aerosol over extended periods during the growing season would eliminate much of the food production in the Northern Hemisphere. Marine ecosystems may be particularly sensitive to the loss of sunlight that would result.”

The following year, this scenario was christened “nuclear winter” in an article in the leading American journal Science[2] written by Richard Turco and colleagues, including Carl Sagan one of America’s most prominent public scientists.  The nuclear winter hypothesis, describing a severe planet-wide drop in temperature, captured the popular imagination during the middle years of the 1980s.  It also provoked a series of scientific workshops and journal articles[3] which explored in more detail the physics, chemistry, biology and ecology resulting from a major exchange of nuclear warheads.

It was around this time that ‘Nuclear Winter’ was published in the UK by Polity Press, the first popular account of the scenario to appear in book form.  I have selected this as my ‘Climate Book of 1985’ for two main reasons.  First, it was addressed to a broad public audience and demonstrated how quickly, and with associated urgency, the narrative of an imaginary nuclear winter gained public attention in the mid-1980s.  It did so more rapidly–and more dramatically–than the rather slower-moving emergence of the science of anthropogenic global warming during the same decade.  Second, the book is a good example of campaigning by activist scientists using emerging scientific – in this case climatic – arguments to support a political cause, in this case unilateral nuclear disarmament.  The relationship between climate science and political activism has again been prominent in recent years, with social movements such as Scientist Rebellion arguing that scientific evidence around climate change warrants aggressive lobbying, if not civic disobedience, by scientists in support of political change[4].

‘Nuclear Winter’ was written by three British scientists working at the Open University (OU) in the UK: two physicists – Owen Greene and Ian Percival — and a biologist, Irene Ridge[5].  The book nicely summaries for a lay audience the science behind the idea of nuclear winter, which had started with Crutzen and Birks less than three years earlier, but which remained rather sketchy.  Greene and colleagues explain the importance of the injections of smoke and dust into the atmosphere following a nuclear conflagration, discuss the scale of the different military scenarios considered, and then speculate about some of the effects of the resulting climatic cooling for plants, animals and people.  They also spend two chapters proposing a range of policy implications of the hypothesis.    

The association of the book with the OU was not coincidental.  A few years earlier, two OU academics, the late physicist and peace activist Mike Pentz and the biologist and neuroscientist Steven Rose, had founded a new social movement, ‘Scientists Against Nuclear Arms’ (SANA).  In 1981, the 47-yr old Pentz had placed a notice in New Scientist magazine advertising a conference intended to found a new scientific organisation with the aim of defusing the threat of nuclear war.  Over 100 people attended and, through its various working groups, SANA went on to publish numerous briefings and booklets about the scientific and technical issues of nuclear disarmament, in particular challenging official government information about the extent of the dangers associated with nuclear war.  SANA was to become one of the forerunner organisations of the broader social movement, Scientists for Global Responsibility, which formed in the UK in 1992 with the aim of promoting the ethical practice and use of science, design and technology.

‘Nuclear Winter’ was therefore a book of advocacy.  Greene, Percival and Ridge made it clear where they stood on the issue and they explicitly acknowledged “all of our colleagues in SANA”, including co-founder Mike Pentz, for their encouragement and advice in producing the book.  The authors argue that, “The threat of nuclear winter introduces some qualitatively new dangers and thereby brings a new dimension and a new urgency to the nuclear debate” (p.164) and, whatever the merits of the nuclear winter hypothesis in 1985,  their concluding position is unambiguous, “No generation, let alone a relatively small group of people, has the right to gamble with the lives of all future generations, not should they be allowed to do so.  There is only one way to avoid this risk: to halt and reverse the nuclear arms race” (p.170). 

I bought my own copy of ‘Nuclear Winter’ in August 1985, shortly after being appointed as a young lecturer in physical geography at the University of Salford.  I placed the book on the reading list for my newly written final year undergraduate course, ‘Contemporary Issues of Climatic Change’, that I first taught in 1985/86 to about 25 students.  In this course, I treated the climatology of nuclear winter alongside other significant climatic issues of the time, such as acid precipitation, drought in the Sahel and greenhouse gas induced global warming.  My thinking in doing so was to show that climatology was not an abstract or arcane corner of the discipline of geography.  I wanted students to understand that questions about climatic change and variability were intimately bound-up with some of the most pressing questions of the decade, not least those about nuclear war, nuclear disarmament and geopolitics.  Greene et al.’s book was timely in this regard.

Scientific debates about the credibility of the nuclear winter hypothesis continued through the mid-late 1980s and offered a politically-charged test-run for the public authority of the first generation of atmospheric General Circulation Models (GCMs) that had been under development for the previous 10 years or so.  Indeed, Josh Howe argues in his book ‘Behind the Curve’ that the reliance of nuclear winter theory on GCMs was a crucial part of the story about the rising public influence of climate modelling[6].  Howe’s account of the nuclear winter controversy in the mid-1980s – a controversy which he claims was seminal in forging new political alliances in the USA between climate scientists, environmental activists and political Democrats – shows how easy it is for climate science to become deeply entangled with ideologies. 

Notwithstanding the bold scientific strokes painted in Greene et al.’s 1985 book, there was widespread recognition by atmospheric scientists of the considerable uncertainties in the presenting scenario, and in some quarters more overt scepticism.  For example, the editor of Nature, John Maddox, wrote in a March 1984 editorial[7] that,

“… there is the strongest case for asking that the prospect of a nuclear winter should not be made into a more substantial bogeyman than it is by those who earnestly wish to avert the prospect of nuclear war as such.  By clouding the case with disputable predictions, they are in danger of weakening it.” 

A more nuanced position was offered by Starley Thompson, at atmospheric scientist at NCAR and co-author with Steve Schneider of a modelling study which turned the extreme scenario of nuclear winter into a “nuclear autumn”.  Writing in Schneider’s journal, Climatic Change in June 1984[8], Thompson editorialised that,

“Neither blindly equating nuclear war with global environmental annihilation, nor dismissing the ‘nuclear winter’ arguments as needlessly alarmist, serves a useful purpose.  As scientists supported by our societies we have an obligation to use our training to critically and dispassionately examine this potential threat to our planet”.

I had picked up the modified metaphor of “nuclear autumn” when, a few years later, I featured the nuclear winter hypothesis in one of my regular newspaper climate columns that in 1988 I had started writing for The Guardian newspaper in the UK.  Titled, ‘Nuclear autumn danger’, it appeared in the paper on Friday 25 November 1988.  Reflecting on five years of research since the original Crutzen and Birks paper, I concluded that, “Although the severity of the nuclear winter predicted by the 1983 model has been scaled down, the clear likelihood of a major global climatic catastrophe following exchanges in a nuclear war remains with us.”

Owen Greene and colleagues wrote their book, ‘Nuclear Winter’, in 1985 with the explicit objective of wanting to halt and reverse the nuclear arms race.  In the absence of a counter-factual world in which there was no nuclear winter hypothesis, it remains impossible to establish just what effect the prospect of a climatic Armageddon had on superpower negotiations later in the 1980s – or, indeed, on the strategic thinking of any of the nine nations currently in possession of nuclear warheads.  The hypothesis has, thankfully, never been tested and it remains an example of not being able to subject the predictions of global climate models to empirical verification.  Nevertheless, it has not stopped some from forming the judgement that, “Nuclear winter theory helped to end the nuclear arms race in the 1980s and helped to produce the Treaty on the Prohibition of Nuclear Weapons in 2017”[9].  And a group of nuclear winter scientists from the 1980s — Alan Robock, Brian Toon, Rich Turco, and Gera Stenchikov — received jointly the 2022 ‘Future of Life Award’ from the Future of Life Institute for “reducing the risk of nuclear war by developing and popularizing the science of nuclear winter.”  Owen Green and his co-authors, writing 37 years earlier, would have been delighted to have known of this outcome.

© Mike Hulme, March 2024

Other significant books published in 1985

Bradley,R.S. (1985) Quaternary Paleoclimatology: Methods of Paleoclimatic Reconstruction. (1st edn.) London: Allen and Unwin.

The 1980s was a decade in which the various environmental sciences that were contributing to the emerging paradigm of Earth System science were consolidated through new institutions and international programs.  Alongside this consolidation, new literature was being published that systematised the knowledge and techniques of these sciences.  At the time this book was published in 1985, Ray Bradley was a 37-year old paleoclimatologist at the University of Massachusetts, Amherst, and ‘Quaternary Paleoclimatology’  rapidly became established as the definitive textbook for scientists venturing into the expanding field of paleoclimate reconstruction, an essential companion science to the new practices of climate modelling.  The longevity and significance of this book was evidenced by second (in 1999) and third (in 2014) editions appearing under the amended title, ‘Paleoclimatology: Reconstructing Climates of the Quaternary’.

Lockwood,J.G. (1985) World Climatic Systems. London: Edward Arnold. 292pp.

Throughout the twentieth century, textbooks on climatology emanated either from academic geographers or else from scientists writing for geography students.  Prominent examples include Austin Miller’s ‘Climatology’ (nine editions between 1931 and 1961), Glenn Trewartha’s ‘An Introduction to Climate’ (five editions, 1937-1980), and Roger Barry and Dick Chorley’s ‘Atmosphere, Weather and Climate’ (nine editions, 1968-2009).  This ‘geographical tradition’ in climatology was gradually over-written in the latter decades of the century by the new science and modelling of the Earth System.  The student textbook, ‘World Climatic Systems’, was published in 1985, at the transition between these two paradigms of climate science.  It was written by a geographer–John Lockwood was professor of geography at the University of Leeds in the UK–and was organised about six different ‘climatic systems’: atmospheric, oceanic, glacial, arid, grassland and forest.  The resulting knowledge of climatic spatial and temporal variability was then applied to energy and food systems. 

[1] Crutzen,P.J. and Birks,J.W. (1982) The atmosphere after a nuclear war: Twilight at noon. Ambio. 11(2/3): 114-125.

[2] Turco,R.P., Toon,O.B., Ackerman,T.P., Pollack,J.B. and Sagan,C. (1983) Nuclear winter: Global consequences of multiple nuclear explosions. Science. 222: 1283-1292.

[3] See, for example: Ehrlich,P.R., Harte,J., Harwell,M.A., et al. (1983) The long-term biological consequences of nuclear war. Science. 222: 1293-1300; Covey,C., Schneider,S.H. and Thompson,S.L. (1984) Global atmospheric effects of massive smoke injections from a nuclear war: results from general circulation model simulations. Nature. 308: 21-25.  A key scientific meeting took place in April 1983 in Cambridge, Massachusetts, enlisting  leading biologists to consider ‘The Long-Term Worldwide Biological Consequences of Nuclear War’, which prompted a series of scientific studies and papers, including the two above.

[4] For example, see: Grossman,D. (2024) Scientists take action on climate change. Nature. 626: 710-712.

[5] Owen Greene shortly thereafter moved to the University of Bradford (in 1987), where he is currently professor of international development and peace studies.  Ian Percival (b.1931) was a theoretical physicist and is now Emeritus Professor of the School of Physics and Astronomy at Queen Mary University, London.  Irene Ridge was a plant physiologist at the OU and in 1991 edited a core OU text book, ‘Plant Physiology’.

[6] See pp.134-144 in: Howe,J.P. (2014) Behind the Curve: Science and the Politics of Global Warming. Seattle, WA: University of Washington Press. 296pp.

[7] Maddox, J. (1984) Nuclear winter not yet established. Nature 308: 11.

[8] Thompson,S.L. (1984) An evolving ‘nuclear winter’: guest editorial. Climatic Change. 6: 105-107.

[9] Stated in: Robock,A., Xia,L., Harrison,C.S., Coupe,J., Toon,O.B., and Bardeen,C.G. (2023) Opinion: How fear of nuclear winter has helped save the world, so far. Atmos. Chem. Phys. 23: 6691–6701.