THE CHRONICLE OF HIGHE R EDUCATION I OCT OBER 25, 2013

People Voice on Climate Change Moves to Harvard By JENNY ROGERS Ms. Oreskes, who is 54, earned change consensus, she says. "If a professor of en­ a Ph.D. in geQlogical research anything, I'm an advocate for un­ vironmental stud­ AOMI ORESKES never in­ and the history of science from derstanding why this issue is im­ ies, bioethics, and tended to become a spokes­ Stanford University in 1990. M­ portant." philosophy at New N person on climate change or ter starting out as a geologist, she To make decisions, she says, York University. science. Then she published an es­ quickly became interested in how policy makers should understand They are studying say in the journal Science in 2004, scientific consensus forms. She "where there's scientific consensus how scientists eval­ in which she laid out the broad found a niche in the history of sci­ and where there isn't." uate one another's scientific consensus that global cli­ ence, eventually specializing in A former colleague, Veerab­ work for large-scale mate change is occurring, and that cold-war-era and contemporary hadran Ramanathan, says Ms. assessments that it is affected by human activities. scientific work. Oreskes's departure was a loss for have influenced en­ Now the woman who brought Her 2004 analysis of climate­ San Diego. "She is one of the few vironmental-policy the world that message has moved change studies was cited in An who talk about contemporary sci­ decisions, such as from the University of California at Inconvenient Truth, a 2006 docu­ ence," says Mr. Ramanathan, a pro­ the reports of the San Diego, where she was a profes­ mentary in which Al Gore warns of fessor of atmospheric and climate Intergovernmen­ sor of history and science studies the consequences of global warm­ sciences at the Scripps Institution tal Panel on Cli­ for 15 years, to Harvard University ing. Her 2010 book, Merchants of of Oceanography there. "She comes mate Change. Or, as a professor of the history of sci­ Doubt, written with the science to a conclusion, and she doesn't shy as Ms. Oreskes puts ence and an affiliated professor of historian Erik M. Conway, stirred away from saying it in the strongest it, "How do scien­ earth and planetary sciences. more controversy. In it, they ar­ sense possible." . tists make sense "I was just ready for a change," gued that certain scientists ob­ Ms. Browne says Ms. Oreskes of what they know she says ofher move this summer. scured the truth in order to dis­ has been "brave" in her open ex­ on behalf of other She had considered environmental credit sound scientific findings on ploration of the moral founda­ people?" Naomi Oreskes jobs but decided she wanted to stay the risks of smoking, global warm­ tion of science. "We are absolutely The question of in academe and focus on the history ing, and other issues. with her in feeling that if there scientific assessment is "so interdis­ and eventually teach a course with of science. "It was a conscim:s deci­ Supporters of those scientists are things that need to be said, we ciplinary," she says. "Science, policy, Ms. Browne on the history of the sion to hold onto that core." have fought back in numerous arti­ should be saying them." jealousy, competition-it's a great, earth. .Janet Browne, chair of the de­ cles and Internet postings that dis­ At Harvard, Ms. Oreskes is great topic." Ms. Oreskes looks forward to partment of the history of science pute the value of Ms. Oreskes's own teaching a graduate introductory There is potential for her to be­ seeing how her research evolves. at Harvard, says she and other work. A document on the Web site course on the history of science and come involved in other interdis­ "If we knew everything, we could members of the hiring committee of the Heartland Institute, a think finishing a book on the history of ciplinary work at Harvard. Ms. close our books and lock our doors were impressed with Ms. Oreskes's tank with libertarian leanings, cold-war oceanography. She has Browne hopes Ms. Oreskes might and say this project of science is expertise and "engaging" way of calls her stand on climate change noted that oceanographers were do research into marine and naval done," she says. "Obviously, that's teaching. "an anti-science position akin to among the first to find evidence of technologies during the cold war not the case." • "Naomi is extremely famous in witchcraft." global warming. our small community" of science Ms. Oreskes says she is not an She is also deep into her latest historians "and indeed famous out­ advocate for any policy but not a research project, in conjunction side of it," Ms. Browne says. "She is "bystander," either. with Michael Oppenheime r, a widely respected and regarded as a "I don't shy away from what I professor of geosciences and in­ terrific public spokesperson for the consider to be the intellectual im­ ternational affairs at Princeton 1 QUOTED value of what we do." plications of my work" on climate- University, and Dale .Jamieson, The golden al!e ofhio-hA'r orl:o.~""-~-- ESSAY BEYOND THE IVORY TOWER This year's essay series highlights the benefits that scientists, science, The Scientific Consensus and technology have brought to society throughout history. on Climate Change Naomi Oreskes climate change is natural. However, none olicy-makers and the media, particular- Academy of Sciences report, Climate of these papers argued that point. ly in the United States, frequently assert Change Science: An Analysis of Some Key This analysis shows that scientists publish- Pthat climate science is highly uncertain. Questions, begins: “Greenhouse gases are ing in the peer-reviewed literature agree with Some have used this as an argument against accumulating in Earth’s atmosphere as a re- IPCC, the National Academy of Sciences, and adopting strong measures to reduce green- sult of human activities, causing surface air the public statements of their professional so- house gas emissions. For example, while dis- temperatures and subsurface ocean temper- cieties. Politicians, economists, journalists, cussing a major U.S. Environmental Pro- atures to rise” [p. 1 in (5)]. The report ex- and others may have the impression of confu- tection Agency report on the risks of climate plicitly asks whether the IPCC assessment is sion, disagreement, or discord among climate change, then–EPA administrator Christine a fair summary of professional scientific scientists, but that impression is incorrect. Whitman argued, “As [the report] went thinking, and answers yes: “The IPCC’s The scientific consensus might, of through review, there conclusion that most of the course, be wrong. If the history of science was less consensus on Without substantial disagreement, observed warming of the teaches anything, it is humility, and no one the science and conclu- scientists find human activities last 50 years is likely to can be faulted for failing to act on what is sions on climate change” have been due to the in- not known. But our grandchildren will are heating the Earth’s surface. on October 29, 2013 (1). Some corporations crease in greenhouse gas surely blame us if they find that we under- whose revenues might concentrations accurately stood the reality of anthropogenic climate be adversely affected by controls on carbon reflects the current thinking of the scientific change and failed to do anything about it. dioxide emissions have also alleged major community on this issue” [p. 3 in (5)]. Many details about climate interactions uncertainties in the science (2). Such state- Others agree. The American Meteoro- are not well understood, and there are am- ments suggest that there might be substantive logical Society (6), the American Geo- ple grounds for continued research to pro- disagreement in the scientific community physical Union (7), and the American vide a better basis for understanding cli- about the reality of anthropogenic climate Association for the Advancement of Science mate dynamics. The question of what to do change. This is not the case. (AAAS) all have issued statements in recent about climate change is also still open. But The scientific consensus is clearly ex- years concluding that the evidence for human there is a scientific consensus on the reality www.sciencemag.org pressed in the reports of the Inter- modification of climate is compelling (8). of anthropogenic climate change. Climate governmental Panel on Climate Change The drafting of such reports and state- scientists have repeatedly tried to make this (IPCC). Created in 1988 by the World ments involves many opportunities for clear. It is time for the rest of us to listen. Meteorological Organization and the United comment, criticism, and revision, and it is Nations Environmental Programme, IPCC’s not likely that they would diverge greatly References and Notes purpose is to evaluate the state of climate sci- from the opinions of the societies’ mem- 1. A. C. Revkin, K. Q. Seelye, New York Times, 19 June 2003, A1.

ence as a basis for informed policy action, bers. Nevertheless, they might downplay 2. S. van den Hove, M. Le Menestrel, H.-C. de Bettignies, Downloaded from primarily on the basis of peer-reviewed and legitimate dissenting opinions. That hy- Climate Policy 2 (1), 3 (2003). 3. See www.ipcc.ch/about/about.htm. published scientific literature (3). In its most pothesis was tested by analyzing 928 ab- 4. J. J. McCarthy et al., Eds., Climate Change 2001: recent assessment, IPCC states unequivocal- stracts, published in refereed scientific Impacts, Adaptation, and Vulnerability (Cambridge ly that the consensus of scientific opinion is journals between 1993 and 2003, and list- Univ. Press, Cambridge, 2001). 5. National Academy of Sciences Committee on the that Earth’s climate is being affected by hu- ed in the ISI database with the keywords Science of Climate Change, Climate Change Science: man activities: “Human activities … are “climate change” (9). An Analysis of Some Key Questions (National Academy Press, Washington, DC, 2001). modifying the concentration of atmospheric The 928 papers were divided into six cat- 6. American Meteorological Society, Bull. Am. Meteorol. constituents … that absorb or scatter radiant egories: explicit endorsement of the consen- Soc. 84, 508 (2003). energy. [M]ost of the observed warming sus position, evaluation of impacts, mitiga- 7. American Geophysical Union, Eos 84 (51), 574 (2003). … 8. See www.ourplanet.com/aaas/pages/atmos02.html. over the last 50 years is likely to have been tion proposals, methods, paleoclimate 9. The first year for which the database consistently due to the increase in greenhouse gas con- analysis, and rejection of the consensus po- published abstracts was 1993. Some abstracts were deleted from our analysis because, although the au- centrations” [p. 21 in (4)]. sition. Of all the papers, 75% fell into the thors had put “climate change” in their key words, the IPCC is not alone in its conclusions. In first three categories, either explicitly or im- paper was not about climate change. recent years, all major scientific bodies in plicitly accepting the consensus view; 25% 10. This essay is excerpted from the 2004 George Sarton Memorial Lecture, “Consensus in science: How do we the United States whose members’ expertise dealt with methods or paleoclimate, taking know we’re not wrong,” presented at the AAAS meet- bears directly on the matter have issued sim- no position on current anthropogenic cli- ing on 13 February 2004. I am grateful to AAAS and the History of Science Society for their support of ilar statements. For example, the National mate change. Remarkably, none of the pa- this lectureship; to my research assistants S. Luis and pers disagreed with the consensus position. G. Law; and to D. C. Agnew, K. Belitz, J. R. Fleming, M. Admittedly, authors evaluating impacts, T. Greene, H. Leifert, and R. C. J. Somerville for helpful The author is in the Department of History and Science discussions. Studies Program, University of California at San Diego, developing methods, or studying paleocli- La Jolla, CA 92093, USA. E-mail: [email protected] matic change might believe that current 10.1126/science.1103618

1686 3 DECEMBER 2004 VOL 306 SCIENCE www.sciencemag.org Published by AAAS C ORRECTIONS AND C LARIFICATIONS ERRATUM Post date 21 January 2005

Essays: “The scientific consensus on climate change” by N. Oreskes (3 Dec. 2004, p. 1686). The final sentence of the fifth paragraph should read “That hy- pothesis was tested by analyzing 928 abstracts, published in refereed scientif- ic journals between 1993 and 2003, and listed in the ISI database with the keywords ‘global climate change’ (9).” The keywords used were “global climate change,” not “climate change.”

www.sciencemag.org SCIENCE Erratum post date 21 JANUARY 2005 1 BOOKS ET AL.

ESSAY REVIEW voices sometimes muffl ed. In Storms of My Grandchildren, Hansen attempts to combine The Climate Change Debates the story of his own efforts with (yet another) attempt to explain the pertinent parts of cli- Philip Kitcher mate science as clearly as he can. Science as a Contact Sport presents Schneider’s n one of the earliest and most eloquent tives on public discussion and policy bears insider account of the struggles to understand pleas for open discussion and debate, on our own times, although the risks may and moderate human-induced atmospheric IJohn Milton wrote: affect our species as a whole and the stakes changes. Other climate scientists, like Mike may be far higher. For three decades, promi- Hulme (University of East Anglia), who live And though all the winds of doctrine were nent climate scientists have been warning of in societies where the level of discussion has let loose to play upon the earth, so Truth be the dangerous effects of the continual emis- usually been more informed, are inclined to in the fi eld, we do injuriously, by licensing sion of greenhouse gases into Earth’s atmo- see matters differently. They hold that contin- and prohibiting, to misdoubt her strength. sphere. They have been attempting to iden- ued debate refl ects the genuine diffi culties of Let her and Falsehood grapple; who ever tify and to explain just what those effects are the underlying issues and sometimes explic- knew Truth put to the worse, in a free and likely to be—for ourselves, our children, and itly chide their colleagues (as Hulme does in open encounter. ( 1) our more remote descendants. And they have Why We Disagree About Climate Change) for been urging a variety of measures that might a tendency to “apocalyptic” pronouncements. Two centuries after Milton, in the same prevent some of the disasters whose possi- So, in refl ections on the debates of the past year in which Charles Darwin published bility they claim to foresee. Yet it is evident decades, there opens up a genuine dispute the Origin, John Stuart Mill’s essay On Lib- that substantial disagreement remains about about the role of scientists in infl uencing pub- erty (2 ) added further arguments for the the consequences for humans and for other lic policy, with some urging a stronger voice free exchange of ideas, suggesting that such species. This is so even in those countries for expert testimony and others recommend- exchange is vital for intellectual and social where citizens have largely accepted the con- ing reticence and even quietism.

health. Although both Milton and Mill stand clusions that anthropogenic global warming In part, the differences between Hansen on October 29, 2013 behind our current acquiescence in the value exists and is likely to raise the average tem- and Schneider, on the one hand, and Hulme, of extensive free discussion, both of them perature on our planet at least 2°C by the end on the other, stem from their concerns with www.sciencemag.org Downloaded from

knew that they were opposing ancient suspi- of the century. In the United States, the state rather different controversies. It is useful to cions about the viability of democracy. The of discussion is less advanced: Denying the differentiate three questions. First is the issue political theorists and philosophers of the reality of human-caused climate change con- of whether human activities, specifically Greco-Roman world viewed ordinary folk tinues to fi gure as a serious possibility in pub- actions that increase the emission of green- as vulnerable to deception and exploitation. lic debates. And a large fraction of the popu- house gases, are contributing to a signifi cant Allowed to determine the direction of the lace believes that scientists’ warnings about average warming of Earth. (As all the expert state, the folk would be easily seduced into the impact of any increases in global temper- authors point out very clearly, there is no sug- believing falsehoods aligned with the inter- atures are exaggerated. gestion that the temperature of every region ests of charismatic leaders, so that the popu- For those who play the role of Cassandra will rise during the next decades.) Second lar voice would enthusiastically clamor for in this drama, such as climatologists James are questions about the probabilities with disastrous policies. Better, then, to entrust Hansen (NASA Goddard Institute for Space which various phenomena (complete melt- the ship of state to wise navigators, whose Studies) and Stephen Schneider (Stanford ing of ice sheets, for example) will occur and wisdom embraced both depth of understand- University), a 30-year effort to alert policy- about their consequences for human beings ing and moral integrity. makers, politicians, and the public to what and other species. Third are considerations The contrast between these two perspec- they perceive as signifi cant dangers can only about what might be done to halt (or even be seen as frustrating. They have been moved reverse) the warming and to limit the dam- to write books, accessible to a general read- aging consequences. Hulme emphasizes The reviewer is in the Department of Philosophy, Colum- bia University, New York, NY 10027, USA. E-mail: psk16@ ership, that will record the ways in which the complexity of the third set of issues. He columbia.edu their warnings have been ignored—and their notes how they are intertwined with diffi cul-

1230 4 JUNE 2010 VOL 328 SCIENCE www.sciencemag.org Published by AAAS BOOKS ET AL. ties about understanding economic trends ing of alternative views. (Although sym- and changes, about global justice, about the pathetic critics might also ponder the fact Merchants of Doubt values assigned to things that are hard to that these two eminent scientists have How a Handful of Scientists Obscured assess in economic terms (ecosystems, the been rebutting the same “alternatives” for the Truth on Issues from Tobacco Smoke continuation of particular forms of human decades). Perhaps continued discussion to Global Warming social life), about practical geopolitics, and could be tolerated, were there no urgency by Naomi Oreskes and Erik M. Conway even about religious perspectives. Focusing about the issue under debate. If they saw Bloomsbury, New York, 2010. 365 pp. $27, £25. on this intricate web of prob- no compulsion to act soon— ISBN 9781596916104. lems, he elaborates an exten- and if they were convinced that sive case for the naturalness the fi ght were fair—Hansen and Online Why We Disagree About Climate Change of continued disagreement. Schneider might share Milton’s Understanding Controversy, Inaction For Hansen and Schneider, sciencemag.org confi dence that truth would ulti- and Opportunity however, the fi rst two ques- To join a mately emerge as victor. Yet the discussion of by Mike Hulme tions are primary (although the issues raised here, stories they tell in their gripping Hansen ventures some pro- go to narratives reveal all too many Cambridge University Press, Cambridge, 2009. posals about the third as well). http://tiny.cc/clichng points at which messages have 432 pp. $80, £45. ISBN 9780521898690. Both contributed to repeated been distorted and suppressed Paper, $29.99, £15.99. ISBN 9780521727327. attempts to persuade successive American because of the short-term interests of eco- administrations of the existence and impor- nomic and political agents. They also dem- Storms of My Grandchildren tance of anthropogenic global warming, and onstrate many ways in which the arena of The Truth About the Coming Climate Schneider participated in lengthy discussions public discussion has been set up to block Catastrophe and Our Last Chance during the preparation of Intergovernmental the widespread acceptance of conclusions to Save Humanity Panel on Climate Change (IPCC) reports— based on an increasing body of evidence. by James Hansen discussions in which voices representing The insiders’ stories of ways in which cru- Bloomsbury, New York, 2009. 320 pp. $25, £18. political interests seem to have forced com- cial information has effectively been with- ISBN 9781608192007. promising the eventual presentation of the held from voters, particularly in the United pertinent scientifi c ideas. Their experiences States, should give us pause about the func- Science as a Contact Sport incline them to emphasize the importance tioning of our democracy. Even more power- Inside the Battle to Save Earth’s Climate of expert judgment, effectively renewing the ful is the account provided by two outstand- ancient worries about the dangers of democ- ing historians who have reviewed a sequence by Stephen H. Schneider racy. Both believe that genuine democratic of controversies around topics of public con- National Geographic, Washington, DC, 2009. participation in the issues can only begin cern. In their fascinating and important study, 303 pp. $28, C$35, £16.99. ISBN 9781426205408. when citizens are in a position to understand Merchants of Doubt, Naomi Oreskes and Erik what kinds of policies promote their inter- M. Conway offer convincing evidence for a The Lomborg Deception ests. To achieve that requires a far clearer and surprising and disturbing thesis. Opposition Setting the Record Straight About unmistakable communication of the consen- to scientifi cally well-supported claims about Global Warming sus views of climate scientists, with respect to the dangers of cigarette smoking, the diffi cul- by Howard Friel the existence of anthropogenic global warm- ties of the Strategic Defense Initiative (“Star Yale University Press, New Haven, CT, 2010. ing and to the chances of various effects, than Wars”), the effects of acid rain, the existence 270 pp. $28, £18.99. ISBN 9780300161038. has hitherto been available. In his choice of of the ozone hole, the problems caused by title, Hansen implicitly questions the frequent secondhand smoke, and—ultimately—the The Climate Solutions Consensus assumption that effects on future generations existence of anthropogenic climate change by David E. Blockstein and Leo Wiegman are subject to some “deep discount.” He was used in “the service of political goals and Island Press, Washington, DC, 2010. 328 pp. explicitly notes that people’s common con- commercial interests” to obstruct the trans- $50, £31. ISBN 9781597266369. Paper, $30, £18.99. cern for the fates of their children and grand- mission to the American public of important ISBN 9781597266741. children provides a shared starting point for information. Amazingly, the same small cadre responding to the changes that might threaten of obfuscators fi gured in all these episodes. Climate Change Science and Policy them. Consequently, if citizens are to be able Oreskes (University of California, San to express their views about things that mat- Diego) and Conway (NASA’s Jet Propulsion Stephen H. Schneider, Armin Rosencranz, ter most to them, they need informed views Laboratory) painstakingly trace the ways in Michael D. Mastrandrea, and Kristin Kuntz-Duriseti, Eds. about the planet on which their descendants which a few scientists, with strong ties to will live. Serious democracy requires reliance particular industries and with conservative Island Press, Washington, DC, 2010. 542 pp. $95, £59. ISBN 9781597265669. Paper, $49.50, £37. on expert opinion. political connections, have played a dispro- ISBN 9781597265676. It is all too easy to be beguiled by an oppo- portionate role in debates about controversial site thought: that democracy demands that questions, infl uencing policy-makers and the The Politics of Climate Change there be extensive public discussion, even general public alike. Typically, these scien- on technical matters, discussion in which tists have obtained their stature in fi elds other by Anthony Giddens all participants operate as equals. Those in than those most pertinent to the debated ques- Polity, Cambridge, 2009. 272 pp. $69.95, £55. the grip of this idea will view Hansen and tion. Yet they have been able to cast enough ISBN 9780745646923. Paper, $22.95, £12.99. Schneider as hysterical and arrogant peo- doubt on the consensus views arrived at by ISBN 9780745646930. ple who aim to short-circuit the proper air- scientists within the relevant disciplines to

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delay, often for a substantial period, wide- None of this would have been possible Media contributions to public confusion— spread public acceptance of consequential without a web of connections among aging what Schneider labels “mediarology”—are hypotheses. They have used their stature in scientists, conservative politicians, and execu- elaborated in a number of these books. There whatever areas of science they originally dis- tives of companies (particularly those involved is a serious question as to whether Ameri- tinguished themselves to pose as experts who in fossil fuels) with a short-term economic can science journalists have conspicuously express an “alternative view” to the genu- interest in denying the impact of the emission failed to discharge what might have seemed inely expert conclusions that seem problem- of carbon into the atmosphere. But it also could their central function: to enlighten the pub- atic to the industries that support them or that not have produced the broad public skepti- lic about topics of concern, in areas where an threaten the ideological directions in which cism about climate change without help from expert consensus has been reached. Howard their political allies hope to lead. the media. As Oreskes and Conway point out, Friel’s The Lomborg Deception offers a care- The extraordinary story of deliberate “balanced coverage” has become the norm in ful analysis of the ways in which the “skep- obfuscation that Oreskes and Conway docu- the dissemination of scientifi c information. tical environmentalist,” Bjørn Lomborg, has ment begins with the delight of the tobacco Pitting adversaries against one another for a selectively used (and sometimes distorted) companies in recruiting Fred Seitz and with few minutes has proven an appealing strat- the available evidence. Friel (an indepen- Seitz’s own connections to “scientists in their egy for television news programs to pursue dent scholar whose previous books have cri- twilight years who had turned to fi elds in which in attracting and retaining viewers. Nor is the tiqued the foreign and Middle East coverage they had no training or experience.” It moves idea of “fair and balanced” coverage, in which of the New York Times) shows how Lomborg’s through the forging of a network of industrial the viewer (or reader) is allowed to decide, claims and his status as an expert were uncrit- and political alliances, and the creation of a confi ned to Fox News. Competing “experts” ically accepted. Apparently, the idea of fram- variety of institutes and think-tanks devoted to have become common on almost all Ameri- ing environmental science in terms of a duel challenging various forms of expert consen- can radio and television programs, the Inter- between rival “expert perspectives” was too sus, to a brilliant chapter in which the authors net is awash in adversarial exchanges among seductive to resist. analyze the reasons why, as of 2009, a signifi - those who claim to know, and newspapers, For half a century, since the pioneer- cant percentage of Americans (43%) contin- too, “sell” science by framing it as a sport ing work of Thomas Kuhn (3), scholars ued to dissent from the minimal claim that (preferably as much of a contact sport as pos- who study the resolution of major scientifi c there is “solid evidence the Earth is warming.” sible). Oreskes and Conway identify the ways debates have understood how complex and As Oreskes and Conway conclude: in which the Washington Times and the Wall diffi cult judgments about the probative value Street Journal have nourished the public sense of data or the signifi cance of unresolved prob- There are many reasons why the United that anthropogenic climate change is a matter lems can be. The major transitions in the his- States has failed to act on global warm- of dispute, how they have given disproportion- tory of the sciences, from the 16th and 17th ing, but at least one is the confusion ately large space to articles and opinion pieces centuries to the present, have involved intri- raised by Bill Nierenberg, Fred Seitz, from the “merchants of doubt,” and how they cate debates among competing research pro- and Fred Singer. have sometimes censored the attempts of seri- grams, among well-informed scientists who ous climate scientists to set the record straight. gave different weight to particular sorts of This apparently harsh claim is thoroughly Even the New York Times, the American news- evidence. It is an absurd fantasy to believe justifi ed through a powerful dissection of the paper that takes science reporting most seri- that citizens who have scant backgrounds ways in which prominent climate scientists, ously, typically “markets” scientifi c research in the pertinent fi eld can make responsible such as Roger Revelle and Ben Santer, were by imposing a narrative based on competition decisions about complex technical matters, exploited or viciously attacked in the press. among dissenting scientists. on the basis of a few fi ve-minute exchanges CREDIT: STEVE COLE/GETTY IMAGES STEVE CREDIT:

1232 4 JUNE 2010 VOL 328 SCIENCE www.sciencemag.org Published by AAAS BOOKS ET AL. among more-or-less articulate speakers or a proved easy. American discussions are likely ety of political stances and value judgments small number of articles outlining alternative to be haunted by the long denial, so that sus- that can incline people to divergent conclu- points of view. Democratic ideals have their picions about alarmism linger. As psycholo- sions about what is likely to happen and what place in the conduct of inquiry, for it is argu- gists have repeatedly discovered, those who might be done. In delineating that diversity, able that there should be more communica- are misinformed and later corrected often he moves the discussion beyond any appeal tion between scientists and outsiders in the lapse into versions of their original error. to polarized stereotypes: on this side, the cap- construction of research agendas, in the dis- Scientists who believe that there are grave tains of industry, their tools, and their dupes; cussion of standards of acceptable risk, and in consequences for Earth and its future inhab- on the other, the fl ower children in sandals. the articulation of policies based on scientifi c itants face a diffi cult dilemma. They can talk Yet Hulme’s book invites misreading. consensus. Genuine democracy, however, in probabilistic terms—typically very impre- His immersion in the language of various requires a division of labor, in which particu- cise probabilistic terms—about possible sce- domains of social studies leads him to write lar groups are charged with the responsibil- narios. If those potential futures are to be as if the theoretical conceptions he deploys ity of resolving questions that bear on the made vivid in ways that might engage citi- in classifying various positions were as reli- interests of individuals and societies. Other zens and inspire them to action, then the sce- ably grounded as the scientifi c fi ndings he so groups, those covering such questions in the narios need to be given in some detail. Yet, clearly and concisely explains. Sometimes, media, have the duty to convey the results so as they become more specifi c, the precision there is even a fashionable indulgence in that citizens can cast their votes as an enlight- about probabilities goes down, even to the skeptical distancing, the use of inverted com- ened expression of freedom, justifi ably aimed extent that it is only responsible to declare mas (scare quotes) to raise a knowing eye- at the outcomes for which they hope. Stag- that some outcome lies within the range of brow. He announces, for example, that he ing a brief disagreement between speakers possibilities. Occasionally, those who raise will tell the story of “how we ‘discovered’ with supposedly equal credentials, especially the alarm are more defi nite. If the Arctic ice that physical climates could change,” before when it is not disclosed that one of them is (including the Greenland ice sheet) melts, going on to give a lucid account of how the answering to the economic aspirations of a polar bears will lose their habitat and the spe- discovery (real discovery) occurred. In a sim- very small segment of the society, is a cynical cies will go extinct; if sea levels rise in the ilar vein, he tells us that the “‘post-normal’ abnegation of that duty. most probable ways, low-lying islands (and character of climate change” requires a wider Because it is so thorough in disclos- many coastal areas, such as the Ganges delta) range of expert voices, that scientists must ing how major policy decisions have been will be submerged. Outcomes like these are concede ground to “other ways of knowing,” delayed or distorted, Merchants of Doubt often met with an uncomfortable shrug. They and that climate change can become “a mir- deserves a wide readership. It is tempting to are to be regretted, of course, but if avoid- ror into which we can look and see exposed require that all those engaged in the business ing them really requires a serious modifi ca- both our individual selves and our collective of conveying scientifi c information to the tion of civilized life, then it seems better to societies.” The concerned environmentalist general public should read it. And that sci- adapt: relocate some polar bears to artifi cially who presses on through Hulme’s discussions ence journalists should abandon the obfus- cooled preserves; transport the unfortunate of the “opportunities” provided for “us” by cating practice of presenting alternatives fl ood victims to higher ground. climate change may eventually give up when with inferior justifi cation as if they were on a Concentration on scenarios that can be he tells his readers to “change our position par with the scientifi c consensus. presented in detail and also justifi ed as likely and examine climate change as an idea of the entails a serious cost. For it encourages a imagination rather than as a problem to be * * * public perception that these are the only out- solved.” Tell it to the Maldives! comes the Cassandras of climate science fear. That response, however, is too impatient. Even if American public opinion were A stereotype easily follows. The movement Hulme’s ideas are more subtle than the (often reformed overnight, so that virtually all cit- toward action derives from an ideology, one maladroit) jargon in which he expresses izens were convinced that anthropogenic centered in a dislike of competitive market them. If his book more explicitly differenti- global warming is likely to raise the average capitalism, a fondness for regulation, a ten- ated areas in which particular groups of peo- temperature of the planet by at least 2°C, that dency to give priority to the needs of the poor, ple might have greater authority, it would be would be only the beginning. Beyond that and an overemphasis on environmental con- possible to recognize the value of his diagno- minimal acceptance lie the diffi cult issues servation. Global warming is a device used ses of the diffi culties that attend debates about of deciding just what the consequences of a by Birkenstock-wearing, tree-hugging, busi- climate change without supposing that he is warmer planet will be and what can be done ness-hating liberal intellectuals for advancing advocating the narcissistic quietism his words about them. Here, too, denial can easily be their political aims. often suggest. He could accept, for example, induced. Those who want to resist regulatory “Ideology” is a word that appears rela- the judgment common to Hansen, Schneider, actions contend that the diffi culties that are tively frequently in Hulme’s Why We Dis- and Oreskes and Conway: that conclusions likely to arise for our descendants have been agree About Climate Change (although he about the reality of anthropogenic climate greatly exaggerated, that whatever problems never explains what he means by it). A clima- change and about the risks that attend some arise will be addressed by people in a bet- tologist who has devoted some serious time to scenarios for the future are matters that can ter economic position than we are today, that studying history and social studies of science, be—and have been—authoritatively decided human beings have shown an admirable abil- Hulme aims to offer a broader perspective on by a scientifi c community to which he him- ity to adapt to changing environments, and so the debates that arise once the initial question self belongs. He should then agree with the on and on and on. In countries that have long of the reality of human-caused global warm- implication that, in this domain, it would be taken anthropogenic climate change as a set- ing has been settled. His book is valuable for foolish to introduce “other ways of know- tled question, agreeing on the expected conse- its diagnosis of the many different levels at ing.” Hulme could reasonably suppose that quences and the appropriate response has not which disagreement can arise and the vari- the public becomes properly engaged at the

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moment when risks have been specifi ed— ing what actions we should take now, it is still fewer understood that the competitive- to the extent that they can be specifi ed—and wise to bring them to the fore. Citizens need cooperative interactions among scientists that citizens’ judgments are crucial to deci- to understand the challenges with respect to often involve unguarded remarks about the sions about what risks count as acceptable. shelter, food supply, water supply, and disease work of rival “teams,” and that references He could emphasize, as he comments in one that are likely to arise for their descendants. to “tricks” frequently advert to strategies for of his best discussions, that any decision as to Hansen’s clear perception that an overwhelm- simplifying complicated mathematical prob- whether a possible future can be tolerated (or ing majority of the world’s population can lems or (as in this case) graphical methods of even welcomed) should be informed by eco- share a concern about the kinds of lives that presenting a conclusion perspicuously, rather nomic considerations, even though ethical will be available to their children and grand- than to stratagems for deceiving the pub- values are crucial to any serious assessment. children is echoed in the decision by the dis- lic. Captured by a naïve and oversimplifi ed Finally, his apparently passive recommenda- tinguished social theorist Anthony Giddens image of what “objective science” is like, it is tion to see ourselves in “the mirror” of cli- (London School of Economics) to ground his easy for citizens to reject claims of scientifi c mate change—like his Kennedyesque injunc- recommendations in the thesis that “objects authority when they discover that scientifi c tion to ask “what climate change can do for in nature can only have value through us” work is carried out by human beings. us”—can be interpreted more sympatheti- (4 ). Although some environmentalists would These revelations probably retarded any cally as a call for a more systematic investi- demur, Giddens’s approach in The Politics of serious American consensus even on the gation of the global challenges that confront Climate Change has the advantage of increas- minimal judgment that is the preliminary to us today and those that our descendants will ing the chances for consensus. Like Hulme, the longer and more diffi cult debate. Mean- face, one that formulates strategies for safe- he is much concerned to recognize the con- while, the disappointment at Copenhagen guarding the future without sacrifi cing the nections among global problems, insisting, can be seen as evidence that the world is interests of those currently living. from the beginning, that the challenges of lapsing into a state of resignation. The emis- To make progress on these issues, there responding to climate change and of meet- sions, of course, do not take a break from the will be a need for generally accessible ing the energy needs of the human popula- hard decisions. accounts of the likely impact that various lev- tion must be faced in tandem. He differs from Nevertheless, there are grounds for the els of global warming will produce. Both Han- Hulme in not attempting any wide survey of hope expressed by Giddens. Among them sen and Schneider describe potential futures, sources of disagreement, and, as readers of is the fact that serious scholars from a vari- with Schneider being particularly insistent his previous works might expect, he is lucid ety of crucial disciplines have written valu- on the important point that scientists owe the and precise in outlining potential courses able books on which future deliberations can public a specifi cation of probabilities (to the of social action. If his book, conceived as a build. Those deliberations will require a new extent that that is possible). Two other recent guide for the perplexed citizen, has a fl aw, that synthesis that involves scientists, social sci- books—The Climate Solutions Consensus lies in the breadth and number of the ideas he entists, historians—and others, too. It is an from the National Council for Science and explores. Those ideas are offered in response embarrassment (at least for me) that philoso- the Environment and Climate Change Sci- to threats he views as profoundly serious: phers have not contributed more to this nec- ence and Policy (for which Schneider served essary conversation. We might clarify some as one of its editors)—offer some helpful It will be a colossal task to turn around a of the methodological issues—for instance, and relatively nontechnical information for society whose whole way of life is con- those concerning the variety of risks involved concerned citizens. The organization of Cli- structed around mobility and a ‘natural in model-building. Perhaps more important, mate Change Science and Policy is particu- right’ to consume energy in a profl igate we could use recent ethical work on respon- larly valuable, because of the volume’s focus way. Yet it isn’t as hopeless an endeavour sibilities to future generations and to distant on specifi c types of changes that would affect as it looks. people to articulate a detailed ethical frame- the lives of future people. It breaks free of the work that might help a planet’s worth of pol- stereotypical concerns about marooned polar * * * icy-makers fi nd their way to consensus. With bears and dispossessed islanders to empha- luck, a broader group of dedicated scholars size facts about rising sea levels and melt- All the books reviewed here were writ- may be galvanized by the books discussed ing glaciers that are not suffi ciently appre- ten before climate change deniers exultantly here, so that the potential disasters Hansen ciated. Thus Peter Gleick’s chapter on water exposed the mistakes made by the IPCC in and Schneider have been warning us about concisely identifi es the likely disruption of announcing the imminent demise of the for 30 years will be averted. Perhaps, in the water supplies and the serious chances of Himalayan glaciers and the “conspiratorial end, truth—and wisdom—will prevail. flood-induced pollution. Similarly, Kristie e-mails” from the East Anglia climate center. Ebi delivers a useful summary of a variety of In the wake of these “important revelations,” References and Notes 1. J. Milton, Areopagitica (London, 1644); www.gutenberg. ways in which our descendants will probably the merchants of doubt were back in busi- org/etext/608. be more vulnerable to infectious diseases and ness. In December 2009, Reuters published 2. J. S. Mill, On Liberty (London, 1859); http://ebooks. respiratory conditions. (Although she omits a discussion by Singer in which he claimed adelaide.edu.au/m/mill/john_stuart/m645o/. concerns about the possible effects of envi- that the IPCC report was based on “distorted 3. T. S. Kuhn, The Structure of Scientifi c Revolutions (Univ. Chicago Press, Chicago, 1962). ronmental change on the evolution of disease raw data” and algorithms that were not shared 4. Giddens derives this view about values from the political vectors and cross-species transmission—per- with other scientists ( 5). Few readers of Sing- philosopher Robert Goodin [see, for example, ( 6)]. haps because, in assessing these events, the er’s presentation, or those given by other long- 5. http://blogs.reuters.com/great-debate/tag/climate- change-conference/. chances are unspecifi able.) standing climate-change deniers, learned that 6. R. Goodin, Green Political Theory (Polity, Cambridge, Even though discussions of the predica- there is signifi cant independent evidence for 1992). ments people will face in the future do not Himalayan glacier melt, although not as rapid exhaust the relevant considerations for decid- as the erroneous sentence implied. Probably 10.1126/science.1189312

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