Global Warming: How Skepticism Became Denial

Abstract

The conversation on global warming started in 1896, when a physical chemist estimated that the mean global temperature would rise several degrees if the level of carbon dioxide in the atmosphere was doubled. The topic eventually became one of the most passionate in the history of science. The author points out that climate experts were initially strongly skeptical of the theory of global warming; it took a variety of evidence to gradually convince them that warming due to human emissions was likely. The public, however, was guided away from this conclusion by a professional public relations effort, motivated by industrial and ideological concerns. Deniers of the scientific consensus avoided normal scientific discourse and resorted to ad hominem attacks that cast doubt on the entire scientific community-while disrupting the lives of some researchers. The author points out that scientists have failed to mount a concerted public relations campaign to defend their position. When trust is lost, he asserts, a determined effort is needed to restore it.

Full text

Bulletin
of the
Atomic
Scientists
IT IS 6 MINUTES TO MIDNIGHT
®
Feature
Global warming: How
skepticism became denial
Spencer Weart
Abstract
The conversation on global warming started in 1896, when a physical chemist estimated that the mean global
temperature would rise several degrees if the level of carbon dioxide in the atmosphere was doubled. The
topic eventually became one of the most passionate in the history of science. The author points out that
climate experts were initially strongly skeptical of the theory of global warming; it took a variety of evidence
to gradually convince them that warming due to human emissions was likely. The public, however, was guided
away from this conclusion by a professional public relations effort, motivated by industrial and ideological
concerns. Deniers of the scientific consensus avoided normal scientific discourse and resorted to ad hominem
attacks that cast doubt on the entire scientific communityÑwhile disrupting the lives of some researchers.
The author points out that scientists have failed to mount a concerted public relations campaign to defend
their position. When trust is lost, he asserts, a determined effort is needed to restore it.
Keywords
climate change, climategate, denial, global warming, greenhouse effect, history, skeptic
Is the science community hopelessly
corrupt? That is the conclusion many
would draw from a letter that senior
physicist Harold Lewis (2010) sent last
October to the American Physical
Society. He accused the Society of pro-
moting a Òpseudoscientific fraud,Ó
namely Òthe global warming scam, with
the (literally) trillions of dollars driving
it, that has corrupted so many scien-
tists...Ó The underlying issue was
whether humanity was causing the tem-
perature of our planet to riseÑa ques-
tion that indeed put at stake trillions of
dollars, although one might wonder how
much of this money went to scientists.
The climate question had led not only
Lewis but other senior scientists to
hurl accusations of bias that increasingly
overshadowed the actual scientific find-
ings. It was an unprecedented attack on
the trust that is the very core of the rela-
tionship between science and society.
How did we get into such a situation?
Every novel scientific idea must
scale a wall of skepticism. First it must
overcome the resistance of scientists
who found the older ideas plausible.
Changing the consensus of the experts
is only a beginning, however; the public
has yet to be convinced. That may never
be completed if the new idea contradicts
Bulletin of the Atomic Scientists
67(1) 41–50
!The Author(s) 2011
Reprints and permissions:
sagepub.co.uk/journalsPermissions.nav
DOI: 10.1177/0096340210392966
http://thebulletin.sagepub.com

widely cherished assumptions about the
natural world. There is yet another
barrier if the idea seems to attack estab-
lished interests such as a religion or
an industry. Then doubt is reinforced
by denial: concerted efforts to repre-
sent the scientific consensus as false.
Nothing shows this process so clearly
as the history of the idea that human
emissions of greenhouse gases must
inevitably produce a global warming.
Beginnings: Skepticism prevails
It took a century to accumulate enough
evidence to convince climate experts
that human activity would warm the
planet. The starting point was a famous
1896 paper written by the Swedish phys-
ical chemist Svante Arrhenius. He esti-
mated that doubling the level of carbon
dioxide in the atmosphere would raise
the mean global temperature by several
degrees. At the time that ArrheniusÕs
paper was published, there were many
theories about what forces regulate cli-
mate. And to those few scientists who
paid attention to such theories, the
level of carbon dioxide seemed as plau-
sible as any. To be sure, ArrheniusÕs cal-
culation had omitted many crucial
effects. For example, a warmer atmo-
sphere would carry more moisture, and
wouldnÕt that make for more clouds,
which would reflect more sunlight and
thus counteract the additional carbon
dioxide? Thus, from the outset, strong
skepticism ruled the field, as is normal
among scientists (for full history and
references, see Weart, 2008).
The initial skepticism changed to out-
right rejection in 1900. New experiments
seemed to show that the part of the infra-
red spectrum that carbon dioxide
affected was ÒsaturatedÓÑthat is, the
carbon dioxide and water vapor that
were already in the atmosphere blocked
radiation so thoroughly that adding
more gas could make no difference.
Henceforth, most scientists considered
ArrheniusÕs idea decisively refuted.
But there was a flaw in this
refutation: The greenhouse effect acts
most crucially high in the atmosphere,
where additional traces of carbon diox-
ide and water vapor both make a big dif-
ference as they intercept radiation.
However, decades passed before this
flaw was recognized. After all, there
were other reasons to reject a predic-
tion of global warming. In particular,
nearly all of the carbon dioxide in the
terrestrial system is dissolved in the
massive oceans, which hold 50 times
more carbon than the atmosphere
does. Thus, whatever gas humans
added to the atmosphere would sink
into the deeps.
That argument reflected deeply held
beliefs about the natural world. The vast
climate system of atmosphere, ocean,
rock, and ice was self-regulating, main-
taining its temperature and chemical
composition over millennia. This grand
equilibrium seemed far beyond anything
mere humans could affect. The oceansÕ
regulation of carbon levels, and the pre-
sumed correlation between temperature
and an increase of cloud reflection, were
examples of benign mechanisms main-
taining a durable Òbalance of nature.Ó
This worldview, which emphasized
and yearned for continuity and stability,
thus reinforced the specific arguments
that anthropogenic global warming
was impossible. Or at least unlikely:
ArrheniusÕs idea continued to be cited
in climate textbooks, if only to argue
against it. With no generally accepted
theory of how climate might change,
42 Bulletin of the Atomic Scientists 67(1)

good scientists would keep all possibili-
ties in mind, however odd. Skepticism
can work both ways.
Revival of the theory
In 1956 the physicist Gilbert N. Plass,
using greatly improved spectroscopic
data and theories and the new electronic
calculators, laid to rest the ÒsaturationÓ
argument. Adding carbon dioxide to the
upper layers of the atmosphere, he
showed, would block additional heat
radiation from leaving the planet.
However, his calculation said nothing
about whether clouds would change
and reflect more sunlight. And anyway
wouldnÕt the oceans absorb all of
humanityÕs emissions? Not according
to a calculation that Roger Revelle pub-
lished with Hans Suess in 1957. Seawater
was a buffered solution, they pointed
out; adding a little carbon dioxide
would alter its acidity enough to make
it harder for more to dissolve. Revelle
encouraged Charles David Keeling to
measure the global carbon dioxide
level directly. After barely two years of
work, Keeling announced in 1960 that
the level was indeed rising. The predic-
tion of global warming could no longer
be dismissed as fallacious.
Of course that did not quell the skep-
ticism that is in the bones of every sci-
entist. Most thought the matter was, at
best, something worth investigating...
by somebody else. Even Plass, Revelle,
and Suess turned to other topics, leaving
Keeling the sole scientist of the day to
devote his entire career to the green-
house question. Over the next decade
the ÒKeeling Curve,Ó which measured
the carbon dioxide level, climbed year
after year, demonstrating that human
activity was indeed great enough to
change the atmosphere noticeably.
Others meanwhile began to work
out how the planetÕs climate system
operated. By the early 1970s a few
groups had separately created computer
models that bore a rough resemblance to
reality. Their work attracted wide atten-
tion when devastating droughts around
the world brought the question of cli-
mate change before the public. Were
the disasters caused by the trash that
humanity was throwing into the airÑnot
only greenhouse gases but smoke, smog,
and dust from farmland? Noting that in
the natural course of events the planet
was due to settle over the course of the
next few thousand years into an ice age,
a few scientists speculated that pollu-
tion would block sunlight and accelerate
the process. But nobody made a confi-
dent prediction, and most felt the
whole matter was altogether uncertain.
Many meteorologists still believed in a
balance of nature; as one leader of the
field declared, ÒThe climatic system is
so robust ...that man has still a long
way to go before his influence becomes
great enough to cause serious disrup-
tionÓ (Mason, 1977).
By the late 1970s scientists found good
reasons to dismiss the theory, never
widely credited, that pollution would
bring a rapid global cooling. Meanwhile,
computer modelers began to experi-
ment with climates different from the
present state. When they increased the
level of carbon dioxide, the model atmo-
spheres warmed up. Several experts
predicted that an anomalous global
temperature rise would become percepti-
ble around the start of the twenty-first
century.
However, computer modeling was a
new mode of research, mistrusted by
Weart 43

many, with a potential yet to be demon-
strated. President Jimmy CarterÕs sci-
ence adviser asked the National
Academy of Sciences to report on the
matter, and a committee was duly
formed. The group studied complex
three-dimensional computer models
developed by teams under Syukuro
Manabe and James Hansen, along
with a variety of simpler models that
calculated in only one dimension (for
example, averaging the atmosphere
over all latitudes and longitudes). All
the models warmed up from one to
several degrees Celsius when the
carbon dioxide level was doubled. The
committee reported in 1979 that they
had tried, but had been unable, to find
any natural mechanism that would pre-
vent this warming from happening
(National Academy of Sciences, 1979).
Academy reports are typically so
careful and conservative that they are
thought to represent a consensus of the
scientific community. This report, how-
ever, represented only a consensus of
the tiny band of experts who had studied
the issue intensively. Other scientists
reserved judgment on a conclusion that
was based, after all, on nothing more
than the newfangled computer model-
ing. That changed after 1980, thanks to
cores drilled in the Greenland and
Antarctic ice caps. This meant that the
level of carbon dioxide and the temper-
ature could be measured back through
the last ice age. The measurements
showed that low levels of the gas had
always correlated with low tempera-
tures, high levels with high tempera-
tures. It was a dramatic confirmation,
totally independent of theory and com-
puters, of ArrheniusÕs speculation that
carbon dioxide and global temperature
are linked.
A question of policy
Through the 1980s more and more
researchers began to take the matter
seriously and undertake their own inves-
tigations. A large conference of experts
in Villach, Austria in 1985 affirmed that
global warming was a problem so severe
that governments should consider poli-
cies to restrict emissions of all green-
house gases. This still represented a
consensus only of the scientists, now a
few hundred, who were most deeply
involved with climateÑand most of
them understood that future warm-
ing was not yet thoroughly proved.
A healthy skepticism continued to pre-
vail even within the small community of
computer modelers. Yet all but a few
could agree that anthropogenic global
warming, while not certain, was a seri-
ous risk and ought to be addressed.
Meanwhile, as predicted, the mean
global temperature was rapidly rising,
and in a pattern that pointed straight at
the greenhouse effect.
In 1988 a major international con-
ference of scientists in Toronto
concluded that anthropogenic climate
change posed a major risk for the secu-
rity of many nations. Sea levels would
rise, uprooting millions of refugees;
heat waves would harm agriculture and
perhaps bring famines; the damage
might provoke deadly conflicts. The
conference report called on the worldÕs
governments to set specific targets for
rapidly reducing greenhouse gas emis-
sions. That same summer saw another
series of severe droughts and other dis-
maying climate news, culminating in
HansenÕs widely publicized claim that
it was virtually certain that global warm-
ing was underway. A poll taken at this
time found that more than half of
44 Bulletin of the Atomic Scientists 67(1)

American adults had heard or read about
the greenhouse effect, a remarkably high
level for a scientific phenomenon. Most
of these citizens thought they would
live to see climate changes. Other polls
found that a majority felt the greenhouse
effect was Òvery seriousÓ or Òextremely
serious.Ó Fewer than one-fifth said they
worried Ònot at allÓ about global warm-
ing or expressed no opinion.
1
In short, by 1989 the scientific com-
munity had formed a rough consensus,
which the public knew and largely
accepted. As with many surprising sci-
entific findings, a few experts dissented.
But out of everything published on cli-
mate change in the peer-reviewed scien-
tific literature, hardly any articles denied
that it was likely (Oreskes, 2004).
The establishment of broad agree-
ment on global warming was not a
revolution like some developments
in geophysics (for example, plate
tectonics), but it did overturn older
assumptions that the climate was self-
regulating and beyond human power to
change. The adherents of this older
model were not so much defeated as iso-
lated and left behind by a steady, relent-
less accumulation of evidence.
In response to this paradigm shift,
politicians were pressed to adopt the
appropriate policies. But the idea of
new taxes and regulations was anathema
to the fossil fuel industries and their
allies in other industries, whose profits
might be lowered; the idea equally
repelled people who, for ideological
reasons, opposed any government
regulation. Corporations and wealthy
individuals already had experience in
developing mechanisms to influence
the public on such issues. Conservative
think tanks and corporate publicists had
worked out tactics in battles over the
health effects of cigarettes, chemical
pesticides, and other issues involving
science, money, and ideology. Their
basic strategy was to create doubt.
It was not necessary to disprove the
scientific consensus; it would suffice
to raise enough questions to convince
the public that there was no consensus
(Hoggan and Littlemore, 2009; Michaels,
2008; Oreskes and Conway, 2010).
In 1989 one of these conservative
institutions, the George C. Marshall
Institute, issued an anonymously
authored ÒreportÓ attacking the consen-
sus view on climate change. Endorsed by
Frederick Seitz, an aging but still
respected physicist with no background
in meteorology, the report skillfully pre-
sented a variety of skeptical arguments.
The arguments were taken up by the
Global Climate Coalition, which was
formed in 1989 by major fossil fuel and
other industrial corporations. Over the
following decades the Coalition and
other organizations would spend tens
of millions of dollars supporting lectures
and writings by a few skeptical scien-
tists, producing slick publications and
videos that were sent to journalists,
and advertising directly to the public.
The criticism fit well with the vis-
ceral distrust of environmentalism
that right-wing political commentators
were propagating. The political dimen-
sion was stressed by conservative
institutions such as the Cato Institute,
Competitive Enterprise Institute,
Heritage Foundation, and many others.
They sponsored pamphlets, press
releases, public lectures, and books, all
arguing that claims of global warming
were a Òscare tacticÓ worked up for self-
ish purposes by power-seeking bureau-
crats and radicals. Nobody needed to
worry about global warming, for it was
Weart 45

all nothing but Òjunk scienceÓ (Jacques
et al., 2008; McCright and Dunlap, 2003;
Oreskes and Conway, 2010; Union of
Concerned Scientists, 2007).
Many journalists presented the issue
as if it were a quarrel between two com-
parable groups of scientists. A study of
US newspapers found that through 1994,
climate scientists who were highly
respected by their peers were cited sub-
stantially more often than the skeptics
associated with conservative think
tanks, but after 1995, as the campaign to
cast doubt grew more active, newspa-
pers cited the two groups about equally.
Reporters were seeking an artificial bal-
ance by matching each ÒproÓ scientist
with an Òanti,Ó although there were
far more of the former (Boykoff and
Boykoff, 2004; McCright and Dunlap,
2000).
From skepticism to denial
The most prominent ÒantiÓ campaigner
was retired physicist S. Fred Singer.
Among other objections, Singer insisted
that the warming seen in global temper-
ature statistics was an artifact of urban-
ization. He should have known that on
the contrary, the Òurban heat islandsÓ
that make cities warmer than the sur-
rounding countryside had been factored
into calculations for half a century; fur-
ther, urbanization, of course, could not
explain the rapid warming seen in the
Arctic, the oceans, etc. Singer and other
skeptics raised countless other ques-
tions. If the world was in fact warming,
wasnÕt that because of increased solar
activity? Or a natural cycle involving
ocean currents? It would take a hundred
pages to detail the arguments. All were
carefully considered by climate scien-
tists, and definitively answered. But the
refutations did not silence the small
band of skeptics nor the conservative
and corporate publicists who drew on
these efforts.
Since people like Singer were highly
selective in their use of data, and
appeared to draw important personal
financial support from conservative
foundations and fossil fuel corporations,
many of their opponents felt they were
merely liars for hire. However, what
appears to be deliberate cherry-picking
of data may be an extreme case of Òcog-
nitive bias,Ó a phenomenon well-known
in science as in daily life. This means
that when people with a strong convic-
tion are presented with a variety of
information, they will cling to the parts
that confirm their bias, and ignore or
reject as unreliable everything else.
Another force at work is Òcognitive dis-
sonance.Ó If people are deeply engaged
in a certain behavior (such as defending
a particular view), they are likely to find
anything that is incompatible with that
behavior (such as contradictory evi-
dence) simply too disturbing to accept.
In any case, the self-styled skeptics
were not proceeding in a normal scien-
tific manner. Scientists continually test
their beliefs, seeking out all possible
contrary arguments and evidence, and
finally publish their findings in peer-
reviewed journals, where further
attempts at refutation are encouraged.
But the small group of scientists who
opposed the consensus on warming pro-
ceeded in the manner of lawyers, consid-
ering nothing that would not bolster
their case, and publishing mostly in
pamphlets, books, and newspapers sup-
ported by conservative interests.
At some point they were no longer skep-
ticsÑpeople who would try to see every
side of a caseÑbut deniers, that is,
46 Bulletin of the Atomic Scientists 67(1)

people whose only interest was in cast-
ing doubt upon what other scientists
agreed was true.
Very few experts among the deniers
continued to act as skeptics, publishing
articles in the peer-reviewed literature.
The only one of these with an important
record of accomplishment was Richard
Lindzen of MIT. Reaffirming the tradi-
tional belief in a self-correcting natural
balance, Lindzen pointed out that
nobody could prove that clouds in the
tropics would not become thicker and
reflect more sunlight as the region got
warmer, and thus prevent further warm-
ing. The modelers could only reply that
their established assumptions about
clouds worked very well. Until some-
body managed to make a model that
could reproduce something at least
vaguely like the present climate, and
that did not warm up when carbon diox-
ide was added, the modelers would stick
by their conclusions. (Eventually obser-
vations by Clement et al. (2009) showed
that warming did not tend to increase
tropical reflection of sunlight.)
Personal attacks
As the deniers found ever less scientific
ground to stand on, they turned to polit-
ical arguments. Some of these policy
arguments were straightforward, raising
serious questions about the efficacy and
expense of proposed carbon taxes and
emission-regulation schemes. But lead-
ing deniers also resorted to ad hominem
tactics.
A red line was crossed in 1996 with
accusations of deliberate dishonesty.
The occasion was the second report of
the Intergovernmental Panel on Climate
Change (IPCC), with its key conclusion
that a human impact on climate was
already discernible. The fossil fuel
industry public relations apparatus and
its allies in right-wing organizations
could not let that stand, and they
launched a variety of reports, letters to
the editor, and the like claiming that the
conclusion was falseÑby intent. Their
principal target was Ben Santer, a main
author of the report. Among other
attacks, an op-ed by physicist Frederick
Seitz in the Wall Street Journal accused
Santer of blatant Òcorruption,Ó falsely
claiming that Santer had fraudulently
altered the reportÕs conclusions in
order to Òdeceive policy makers and
the public.Ó
Such a public smear of one leading
scientist by another was unprecedented
in the history of science. Santer
remarked that he had to spend the
better part of the following summer
dealing with journalists and e-mails;
the pressure reportedly contributed to
his divorce. On each side, some people
were coming to believe that they faced a
dishonest conspiracy, driven by ideolog-
ical bias and naked self-interest (Bolin,
2007; Edwards and Schneider, 2001;
Lahsen, 1999; Masood, 1996; Oreskes
and Conway, 2010; Santer, 2010; Seitz,
1996; Stevens, 1999).
This battle even found its way
into popular culture when Michael
CrichtonÕs State of Fear became a best-
selling thriller in 2004. The plot revolved
around a fantasy that fear of global
warming was a deception propagated
by evil conspirators and their dupes.
Crichton played upon a theme popular
on the right wing: The scientific estab-
lishment was arrogant and untrust-
worthy, corrupted by a lust for fame
and political power on behalf of liberal-
ism. The novel, and many non-fictional
works around that time, demonstrated
Weart 47

that the attack was no longer just against
the climate science community: It was
open warfare against science itself (see
e.g., Mooney, 2005).
CrichtonÕs novel was just one exam-
ple of how denial took on a life of its
own in the early twenty-first century,
expanding beyond the sphere of well-
funded conservative think tanks and
publicity experts. Websites and blogs
that confidently denied the scientific
consensus proliferated. Some of these
were maintained by paid professionals,
but others by independent citizens.
They passed around plausible-sounding
arguments and fragments of anomalous
data. There are always anomalies at the
research front, of course. Some of the
arguments were valid skepticism that
provoked serious research to clarify,
and in a few cases correct, published
results. But as soon as scientists
resolved a problem, the deniers pre-
sented a new one.
Meanwhile what we may call Òzombie
argumentsÓÑdead arguments raised
from their gravesÑsurvived among the
WebÕs countless niches. The old claims
that the carbon dioxide spectra was sat-
urated, that urban heat explained the
observed global warming, and a hundred
others, long since refuted, kept convinc-
ing novice readers that claims of global
warming were nonsense. The deniers
constructed what one observer called
an Òalternative universeÓ where Òbasic
findings of mainstream science are
rejected or ignoredÓ (Ruddiman, 2005:
187, see ch. 18).
Consequences
Personal attacks proliferated. Leading
researchers were assaulted with count-
less questions and demands for
information, often disingenuous, and
even investigations and lawsuits. They
were insulted, slandered, and sent so
many death threats that some had to
take security measures. The only com-
parable case in science was the vilifica-
tion and threats showered on prominent
defenders of DarwinÕs theory of evolu-
tion. Even that did not reach the broad
scale and public prominence of the
attacks not only on individuals, but on
the community of climate scientists as
a whole. Some leading climate scientists
found a large part of their time had to be
spent not doing research, as they would
have preferred, but responding to
attacks and denial.
Another line was crossed in 2010
with the theft and publication of thou-
sands of e-mails involving a few climate
researchers. The media dubbed the
affair Òclimategate,Ó implying a scandal.
Although official investigations turned
up no malfeasance on the part of the
climate scientists, suspicious-sounding
quotes wrenched out of context were
permanently embedded in the publicÕs
memory. By implication, not only were
these few researchers dishonest in how
they reported their research, but so were
hundreds of others who had indepen-
dently reported confirmatory findings.
2
The public, and large sections of the
press, found it difficult to distinguish
among the sources of information. The
scientific consensus announced in the
IPCCÕs reports was growing stronger:
Many experts who in 2001 were 90 per-
cent convinced that humans were caus-
ing global warming had become 95 or
99 percent convinced by 2007. Every sci-
entist, even perennial skeptics, agreed at
least that the world had grown signifi-
cantly warmer since the 1960s. Yet
more than a third of the American
48 Bulletin of the Atomic Scientists 67(1)

public now believed that Òmost scien-
tists are unsure about whether global
warming is occurring or not.Ó
3
The
deniers had been effective.
As a defense mechanism, denial is
familiar to psychologistsÑfor example,
when somebody is diagnosed with a
fatal cancer and refuses to believe it.
Psychologists studying how citizens
reacted to warnings of climate change
found that this type of denial was
common. The more harmful and costly
global warming was said to be, the
more some people insisted it was not a
real problem (American Psychological
Association, 2009).
Even among people who believed the
warnings, a majority found many rea-
sons to avoid actually doing anything.
They convinced themselves that the
danger was remote in time and space
and would not affect them person-
allyÑlet the polar bears worry about it.
Or they believed, wrongly, that anything
they could do to mitigate the problem
would be both expensive and ineffective.
They believed it was up to others to
handle the problem; some trusted scien-
tists to come up with an easy technical
solution. Given this public mood, it was
easy for politicians to avoid taking
action that would have been unwelcome
in powerful circles. It was almost as if
the less doubt scientists felt, the stronger
denial became everywhere else.
Once trust is lost, a determined effort
is needed to restore it. The scientific
community is still widely trusted, but it
is losing credibility, and that will bring
losses of students and funding. People
who feel threatened by scientific find-
ings have mobilized extensive, coordi-
nated, professional efforts to defend
their ideologies and their profits. The
position of science will continue to
deteriorate until scientists respond in
kind with broad and well-organized
public-relations campaigns.
Notes
1. USMOR.ATS9.R11 and USGALLUP.051589.
R3J, data furnished by Roper Center for
Public Opinion Research, Storrs, CT.
2. For recent denial and harassment in general,
see Hansen (2009); Schneider (2009); Pearce
(2010); and http://realclimate.org, passim.
3. Gallup (2010). For recent polls see: http://
www.pollingreport.com/enviro.htm.
References
American Psychological Association, Task Force on
the Interface between Psychology and Global
Climate Change (2009) Psychology and Global
Climate Change: Addressing a Multi-faceted
Phenomenon and Set of Challenges. Available at:
http://www.apa.org/science/about/publica-
tions/climate-change.aspx.
Bolin B (2007) A History of the Science and Politics
of Climate Change: The Role of the
Intergovernmental Panel on Climate Change.
Cambridge: Cambridge University Press.
Boykoff MT and Boykoff JM (2004) Balance as bias:
Global warming and the US prestige press. Global
Environmental Change 14: 125”136.
Clement AC, Burgman R and Norris JR (2009)
Observational and model evidence for positive
low-level cloud feedback. Science 325: 460”464.
Edwards PN and Schneider SH (2001) Self-govern-
ance and peer review in science-for-policy: The
case of the IPCC Second Assessment Report.
In: Miller CA and Edwards PN (eds) Changing the
Atmosphere: Expert Knowledge and Environmental
Governance. Cambridge, MA: MIT Press, 219”246.
Hansen J (2009) Storms of My Grandchildren: The
Truth about the Coming Climate Catastrophe and
Our Last Chance to Save Humanity. New York:
Bloomsbury USA.
Hoggan J with Littlemore R (2009) Climate Cover-up:
The Crusade to Deny Global Warming.
Vancouver: Greystone.
Jacques PJ, Dunlap RE and Freeman M (2008) The
organization of denial: Conservative think tanks
and environmental scepticism. Environmental
Politics 17: 349”385.
Lahsen MH (1999) The detection and attribution
of conspiracies: The controversy over chapter 8.
Weart 49

In: Marcus GE (ed.) Paranoia Within Reason:
A Casebook on Conspiracy as Explanation.
Chicago: University of Chicago Press, 111”136.
Lewis H (2010) Letter to American Physical Society. 8
Oct. Available at: http://news-starextra.com/
blog/?tag¼ucsb.
Mason BJ (1977) Has the weather gone mad? The New
Republic 177(5): 21”23.
Masood E (1996) Climate report Òsubject to scientific
cleansingÓ. Nature 381: 546.
McCright AM and Dunlap RE (2003) Defeating
Kyoto: The conservative movementÕs impact on
U.S. climate change policy. Social Problems 50:
348”373.
McCright AM and Dunlap RE (2000) Challenging
global warming as a social problem: An analysis
of the conservative movementÕs counter-claims.
Social Problems 47: 499”522.
Michaels D (2008) Doubt Is Their Product. How
IndustryÕs Assault on Science Threatens Your
Health. New York: Oxford University Press.
Mooney C (2005) The Republican War on Science.
New York: Basic Books.
National Academy of Sciences, Climate Research
Board. (1979) Carbon Dioxide and Climate: A
Scientific Assessment. Washington, DC: National
Academy of Sciences.
Oreskes N (2004) Beyond the ivory tower: The sci-
entific consensus on climate change. Science 306:
1686.
Oreskes N and Conway EM (2010) Merchants of
Doubt: How a Handful of Scientists Obscured the
Truth on Issues from Tobacco Smoke to Global
Warming. New York: Bloomsbury.
Pearce F (2010) The Climate Files: The Battle for the
Truth about Global Warming. London: Guardian
Books/Random House.
Ruddiman WF (2005) Plows, Plagues and Petroleum:
How Humans Took Control of Climate. Princeton,
NJ: Princeton University Press.
Santer B (2010) Close encounters of the absurd
kind. February 24. Available at: http://www.
realclimate.org/index.php/archives/2010/02/
close-encounters-of-the-absurd-kind/.
Schneider SH (2009) Science as a Contact Sport:
Inside the Battle to Save the EarthÕs Climate.
Washington, DC: National Geographic.
Seitz F (1996) A major deception on global warming.
Wall Street Journal. June 12.
Stevens WK (1999) The Change in the Weather:
People, Weather and the Science of Climate.
New York: Delacorte.
Union of Concerned Scientists (2007) Smoke, Mirrors
& Hot Air: How Exxonmobil Uses Big TobaccoÕs
Tactics to Manufacture Uncertainty on Climate
Science. Cambridge, MA: Union of Concerned
Scientists. Available at: http://www.ucsusa.org/
assets/documents/global_warming/
exxon_report.pdf.
Weart S (2008) The Discovery of Global Warming.
Cambridge, MA: Harvard University Press, 2nd
edn. Expanded version available at: http://
www.aip.org/history/climate.
Author biography
Spencer Weart recently retired as Director
of the Center for History of Physics of the
American Institute of Physics, US. His most
recent book is The Discovery of Global
Warming (Harvard University Press),
expanded as a comprehensive historical web-
site at: www.aip.org/history/climate. He is cur-
rently working on a new edition of his book
Nuclear Fear: A History of Images (Harvard
University Press).
50 Bulletin of the Atomic Scientists 67(1)