The Top Five Skeptical Climate-Change Scientists
1. Lennart O. Bengtsson
Bengtsson was born in Trollhättan, Sweden, in 1935. He holds a PhD (1964) in meteorology from the University of Stockholm. His long and productive career included positions as Head of Research and later Director at the European Centre for Medium-Range Weather Forecasts in Reading in the UK (1976 — 1990), and as Director of the Max Planck Institute for Meteorology in Hamburg (1991 — 2000). Bengtsson is currently Senior Research Fellow with the Environmental Systems Science Centre at the University of Reading, as well as Director Emeritus of the Max Planck Institute for Meteorology.
Bengtsson’s scientific work has been wide-ranging, including everything from climate modelling and numerical weather prediction to climate data and data assimilation studies. Most recently, he has been involved in studies and modeling of the water cycle and extreme events. From his twin home bases in the UK and Germany, he has cooperated closely over the years with scientists in the US, Sweden, Norway, and other European countries.
Bengtsson is best known to the general public due to a dispute which arose in 2014 over a paper he and his colleagues had submitted to Environmental Research Letters, but which was rejected for publication for what Bengtsson believed to be “activist” reasons. The paper disputed the uncertainties surrounding climate sensitivity to increased greenhouse gas concentrations contained in the Intergovernmental Panel on Climate Change (IPCC) Fourth and Fifth Assessment Reports. Bengtsson and his co-authors maintained that the uncertainties are greater than the IPCC Assessment Reports claim. The affair was complicated by the fact that Bengtsson had recently agreed to serve on the board of the Global Warming Policy Foundation (GWPF), a climate skeptic organization. When Bengtsson voiced his displeasure over the rejection of his paper, and mainstream scientists noticed his new affiliation with the GWPF, intense pressure was brought to bear, both in public and behind the scenes, to force Bengtsson to recant his criticism of the journal in question and to resign from the GWPF. He finally did both of these things, but not without noting bitterly in his letter of resignation:
I have been put under such an enormous group pressure in recent days from all over the world that has become virtually unbearable to me. If this is going to continue I will be unable to conduct my normal work and will even start to worry about my health and safety. I see therefore no other way out therefore than resigning from GWPF. I had not expecting [sic] such an enormous world-wide pressure put at me from a community that I have been close to all my active life. Colleagues are withdrawing their support, other colleagues are withdrawing from joint authorship etc.
I see no limit and end to what will happen. It is a situation that reminds me about the time of McCarthy. I would never have expecting [sic] anything similar in such an original peaceful community as meteorology. Apparently it has been transformed in recent years.
Bengtsson is the author or co-author of over 180 peer-reviewed journal articles and book chapters, as well as co-editor of several books (see below). In addition to numerous grants, commission and board memberships, honorary degrees, and other forms of professional recognition, he has received the Milutin Milanković Medal (1996) bestowed by the European Geophysical Society, the Descartes Prize (2005) bestowed by the European Union, the International Meteorological Organization Prize (2006), and the Rossby Prize (2007) bestowed by the Swedish Geophysical Society. Bengtsson is an Honorary Member of the American Meteorological Society (AMS), a Member of the New York Academy of Sciences and the Gesellschaft Deutscher Naturforscher und Ärzte, an Honorary Fellow of the Royal Meteorological Society (UK), and a Fellow of the Swedish Academy of Science, the Finnish Academy of Science, and the European Academy.
2. John R. Christy
Christy was born in Fresno, California, in 1951. He holds a PhD (1987) in atmospheric science from the University of Illinois. He is currently Distinguished Professor of Atmospheric Science and Director of the Earth System Science Center at the University of Alabama in Huntsville.
Christy is best known for work he did with Roy W. Spencer beginning in 1979 on establishing reliable global temperature data sets derived from microwave radiation probes collected by satellites. Theirs was the first successful attempt to use such satellite data collection for the purpose of establishing long-term temperature records. Although the data they collected were initially controversial, and some corrections to the interpretation of the raw data had to be made, the work — which is coming up on its fortieth anniversary — remains uniquely valuable for its longevity, and is still ongoing. Christy has long been heavily involved in the climate change/global warming discussion, having been a Contributor or Lead Author to five Intergovernmental Panel on Climate Change (IPCC) reports relating to satellite temperature records. He was a signatory of the 2003 American Geophysical Union’s (AGU) statement on climate change, although he has stated that he was “very upset” by the AGU’s more extreme 2007 statement.
Christy began voicing doubts about the growing climate-change consensus in the 2000s. In an interview with the BBC from 2007, he accused the IPCC process of gross politicization and scientists of succumbing to “group-think” and “herd instinct.”; In 2009, he made the following statement in testimony to the House Ways and Means Committee (altogether, he has testified before Congress some 20 times):
From my analysis, the actions being considered to “stop global warming” will have an imperceptible impact on whatever the climate will do, while making energy more expensive, and thus have a negative impact on the economy as a whole. We have found that climate models and popular surface temperature data sets overstate the changes in the real atmosphere and that actual changes are not alarming. And, if the Congress deems it necessary to reduce CO2 emissions, the single most effective way to do so by a small, but at least detectable, amount is through the massive implementation of a nuclear power program.
Christy has not been shy about publicizing his views, making many of the same points in an op-ed piece he published with a colleague in 2014 in the Wall Street Journal. In an interview with the New York Times published that same year, he explains the price he has had to pay professionally for his skeptical stance toward the climate-change consensus. However, Christy stands his ground, refusing to give in to ad hominem attacks or the exercise of naked political power, insisting the issues must be discussed on the scientific merits alone.
Christy is the author or co-author of numerous peer-reviewed journal articles and book chapters (for a selection of a few of his best-known articles, see below). In 1991, Christy was awarded the Medal for Exceptional Scientific Achievement bestowed by the National Aeronautics and Space Administration (NASA) for his groundbreaking work with Spencer. A Fellow of the American Meteorological Society (AMS), since 2000 Christy has been Alabama’s official State Climatologist.
3. Judith A. Curry
Curry was born in 1953. She holds a PhD (1982) in geophysical sciences from the University of Chicago. She has taught at the University of Wisconsin, Purdue University, Pennsylvania State University, the University of Colorado at Boulder, and Georgia Institute of Technology (Georgia Tech). In 2017, under a torrent of criticism from her colleagues and negative stories in the media, she was forced to take early retirement from her position as Professor in the School of Earth and Atmospheric Sciences at Georgia Tech, a position she had held for 15 years (during 11 of those years, she had been Chair of the School). Curry is currently Professor Emerita at Georgia Tech, as well as President of Climate Forecast Applications Network, or CFAN (see below), an organization she founded in 2006.
Curry is an atmospheric scientist and climatologist with broad research interests, including atmospheric modeling, the polar regions, atmosphere-ocean interactions, remote sensing, the use of unmanned aerial vehicles for atmospheric research, and hurricanes, especially their relationship to tornadoes. Before retiring, she was actively researching the evidence for a link between global warming and hurricane frequency and severity.
Curry was drummed out of academia for expressing in public her reservations about some of the more extreme claims being made by mainstream climate scientists. For example, in 2011, she published (with a collaborator) an article stressing the uncertainties involved in climate science and urging caution on her colleagues. After having posted comments along these lines on other people’s blogs for several years, in 2010, she created her own climate-related blog, Climate Etc. (see below), to foster a more open and skeptical discussion of the whole gamut of issues involving climate change/global warming. She also gave testimony some half dozen times between 2006 and 2015 to Senate and House subcommittees, expressing in several of them her concerns about the politicization of the usual scientific process in the area of climate change. Writing on her blog in 2015 about her most-recent Congressional testimony, Curry summarized her position as follows:
The wickedness of the climate change problem provides much scope for disagreement among reasonable and intelligent people. Effectively responding to the possible threats from a warmer climate is made very difficult by the deep uncertainties surrounding the risks both from the problem and the proposed solutions.
The articulation of a preferred policy option in the early 1990’s by the United Nations has marginalized research on broader issues surrounding climate variability and change and has stifled the development of a broader range of policy options.
We need to push the reset button in our deliberations about how we should respond to climate change.
Finding herself denounced as a “climate change denier” and under intense pressure to recant her views, in 2017 Curry instead took early retirement from her job at Georgia Tech and left academia, citing the “craziness” of the present politicization of climate science. She continues to be active in the field of climatology through her two blogs and her many public lectures.
Curry is the author or co-author of more than 180 peer-reviewed journal articles and book chapters, as well as the co-author or editor of three books (see below). She has received many research grants, been invited to give numerous public lectures, and participated in many workshops, discussion panels, and committees, both in the US and abroad. In 2007, Curry was elected a Fellow of the American Association for the Advancement of Science (AAAS).
4. Richard S. Lindzen
Lindzen was born in Webster, Massachusetts, in 1940. He holds a PhD (1964) in applied mathematics from Harvard University. He is currently Professor Emeritus in the Department of Earth, Atmospheric and Planetary Sciences at MIT.
Already in his PhD dissertation, Lindzen made his first significant contribution to science, laying the groundwork for our understanding of the physics of the ozone layer of the atmosphere. After that, he solved a problem that had been discussed for over 100 years by some of the best minds in physics, including Lord Kelvin, namely, the physics of atmospheric tides (daily variations in global air pressure). Next, he discovered the quasi-biennial oscillation (QBO), a cyclical reversal in the prevailing winds in the stratosphere above the tropical zone. Then, Lindzen and a colleague proposed an explanation for the “superrotation” of the highest layer of Venus’s atmosphere (some 50 times faster than the planet itself), a model that is still being debated.
The idea for which Lindzen is best known, though, is undoubtedly the “adaptive infrared iris” conjecture. According to this model, the observed inverse correlation between surface temperature and cirrus cloud formation may operate as a negative feedback on infrared radiation (heat) build-up near the earth’s surface. According to this proposal, decreasing cirrus cloud formation when surface temperatures rise leads to increased heat radiation into space, while increasing cirrus cloud formation when surface temperatures decline leads to increased heat retention — much as the iris of the human eye adapts to ambient light by widening and narrowing. If correct, this phenomenon would be reason for optimism that global warming might be to some extent self-limiting. Lindzen’s hypothesis has been highly controversial, but it is still being discussed as a serious proposal, even by his many critics.
Lindzen was a Contributor to Chapter 4 of the 1995 Intergovernmental Panel on Climate Change (IPCC) Second Assessment, and to Chapter 7 of the 2001 IPCC Working Group 1 (WG1). Nevertheless, in the 1990s, Lindzen began to express his concern about the reliability of the computer models upon which official IPCC and other extreme climate projections are based. He has been especially critical of the notion that the “science is settled.” In a 2009 Wall Street Journal op-ed, he maintained that the science is far from settled and that “[c]onfident predictions of catastrophe are unwarranted.” For his trouble, Lindzen has suffered the usual brutal, ad hominem attacks from the climate-change establishment.
Lindzen is author or co-author of nearly 250 peer-reviewed journal articles and book chapters, as well as author, co-author, or editor of several books, pamphlets, and technical reports (see below). He is a Member of the US National Academy of Sciences (NAS) and the Norwegian Academy of Science and Letters, and a Fellow of the American Academy of Arts and Sciences, the American Association for the Advancement of Science (AAAS), the American Geophysical Union (AGU), and the American Meteorological Society (AMS).
5. Nir J. Shaviv
Shaviv was born in Ithaca, New York, in 1972, but was raised in Israel. He holds a doctorate (1996) in physics from the Israel Institute of Technology in Haifa. He spent a year as an IBM Einstein Fellow at the highly prestigious Institute for Advanced Study in Princeton, New Jersey (2014 — 2015). He is currently Professor and Chair of the Racah Institute of Physics at the Hebrew University of Jerusalem.
Shaviv first made a name for himself (see his 1998 and 2001 papers, below) with his research on the relationship between inhomogeneities in stellar atmospheres and the Eddington limit (the equilibrium point at which the centrifugal force of stellar radiation production equals the centripetal force of gravitation). This theoretical work led to a concrete prediction that was later confirmed telescopically (see the 2013 Nature paper listed below).
Of more direct relevance to the climate-change debate was a series of papers Shaviv wrote, beginning in 2002 (see below), detailing a bold theory linking earth’s ice ages with successive passages of the planet through the various spiral arms of the Milky Way galaxy, and with cosmic radiation more generally. He has also expressed his conviction that variations in solar radiation have played an equal, if not greater, role in the observed rise in mean global temperature over the course of the twentieth century than has human activity (see his 2012 paper, below). He maintains, not only that anthropogenic greenhouse gases have played a smaller role in global warming than is usually believed, but also that the earth’s climate system is not nearly so sensitive as is usually assumed.
In recent years, Shaviv has become an active critic of the results and predictions of the Intergovernmental Panel on Climate Change (IPCC) and other organizations supporting the consensus view. In particular, he rejects the often-heard claim that “97% of climate scientists” agree that anthropogenic climate change is certain and highly dangerous. Shaviv emphasizes (see the video clip, below) that “science is not a democracy” and all that matters is the evidence for these claims — which he finds deficient.
Shaviv is the author or co-author of more than 100 peer-reviewed journal articles or book chapters, of which some of the most important are listed below.