SCIENCE science.org 5 NOVEMBER 2021 • VOL 374 ISSUE 6568 AINSIGHTSPHOTO: STEPHANIE MITCHELL/HARVARD UNIVERSITY
By Geoffrey SupranO
n Earth Day, 2021, New York City
sued ExxonMobil and other firms
“for systematically and intention-
ally deceiving New Yorkers” about
climate change with “false advertis-
ing and greenwashing” ( 1 ). New York
joins dozens of cities and states in accusing
the fossil fuel industry of endangering the
public by knowingly denying the science of
climate change for decades ( 2 ). Increasingly,
these legal challenges seek to hold fossil
fuel companies accountable not just for
outright climate denial ( 3 ), but for subtler
forms of “deceptive marketing”
that have served to delay action
on climate change ( 4 ).
Naomi Oreskes and I recently
published the first quantitative
assessment of how ExxonMobil
has used language to subtly
yet systematically shape public
discourse in misleading ways
( 5 ). By nature and by design,
climate “delayism” is more insidious than
denialism. To uncover these subtler tactics
while also minimizing subjective judgments
of language, our research brings statisti-
cal techniques from the field of computa-
tional linguistics to bear upon a discipline
traditionally dominated by qualitative
approaches.
Our findings are clear: ExxonMobil has
used—and continues to use—rhetoric that
mimics the tobacco industry in three key
ways: (i) publicly downplaying the reality
and seriousness of climate change, (ii) pre-
senting fossil fuel dominance as reasonable
and inevitable, and (iii) shifting responsibil-
ity for climate change away from itself and
onto consumers.
How did we arrive at our conclusions?
We analyzed 212 documents published be-
tween 1972 and 2019, including all internalcompany memos that led to allegations
against ExxonMobil and peer-reviewed
publications offered by the company in re-
sponse. We also examined all of Mobil and
ExxonMobil’s paid “advertorials” concern-
ing climate change published in The New
York Times, as well as all of ExxonMobil’s
flagship climate reports. We processed the
text of these documents using a machine
learning model to identify recurring topics.
We then statistically compared how often
terms and topics appeared in one set of doc-
uments versus another—a translation and
expansion of techniques previously used to
study tobacco industry documents ( 6 ).
Our analysis showed that ExxonMobil’s
advertorials and flagship reports em-
phasized certain terms and topics while
avoiding others, creating misleading pub-
lic narratives about climate change. One
example can be found in the rhetoric of
“risk,” which Exxon and Mobil systemati-
cally introduced as a modifier to “climate
change” after their merger in 1999. By
definition, a risk is something that may or
may not happen. In characterizing climate
change as a risk, ExxonMobil implied that
it was a possibility, but not necessarily a
reality—even after climate scientists had
demonstrated that it was already under-
way. One ExxonMobil manager saw this
as “an effort” by then-CEO Rex
Tillerson “to carefully reset the
corporation’s profile on climate
positions so that it would be...
less exposed” ( 7 ). It was also a
reprisal of the tobacco industry
playbook, wherein the public
was told that smoking was “a
risk factor for certain diseases”
but “not a proven cause” ( 8 ).
To this day, ExxonMobil, Chevron, and
ConocoPhillips continue to call human-
caused climate change a “risk” rather than
a reality ( 9 – 11 ).
ExxonMobil’s public-facing documents
also statistically overused terms that shifted
responsibility for climate change from the
producer to the consumer. In private, the
company willingly recognized climate
change as a “fossil fuel” problem caused by
“fossil fuel combustion”—i.e., by the compa-
ny’s products. In public, however, the com-
pany overwhelmingly presented climate
change as caused by the “energy demand”
of “consumers”; a problem to be solved by
“energy efficiency” ( 5 ). ExxonMobil’s ad-
vertorials referred only to “greenhouse gas
emissions,” while, just as often, their scien-
tists more-specifically labeled them “fossil
fuel emissions” and “fossil fuel CO 2 .”
Using an inductive method called frame
analysis ( 12 ) to further examine the adver-
torials, we found that ExxonMobil conflatesSOCIAL SCIENCESFueling their
own climate
narrative
Using techniques from big
data to decode Big Oil’s
climate change propaganda
Department of the History of Science, Harvard University,
Cambridge, MA 02139, USA. Email: [email protected]PRIZE ESSAY
FINALIST
Geoffrey Supran
Geoffrey Supran
received his
undergraduate
degree from Trinity
College, University
of Cambridge, and a PhD from the
Massachusetts Institute of Technol-
ogy (MIT). After completing joint
postdoctoral fellowships at MIT and
Harvard University, Geoffrey became
a research fellow in the Department
of the History of Science at Harvard
in 2019 and also Director of Climate
Accountability Communication at
the Climate Science Social Network
in 2020. His research focus is the
quantitative historical analysis of
climate change disinformation and
propaganda by fossil fuel interests.
science.org/doi/10.1126/
science.abm3434