A generation ago, students urged colleges to sell their stock in companies doing business in Apartheid South Africa. At least 155 colleges and universities, as well as 26 state governments, 22 countries, and 90 cities, partially or fully divested. One of the first private institutions to divest was Columbia University, whose trustees said in 1978 that they had done so “to maintain educational leadership,” which demanded “ethical and humane positions that give effective expression to our highest national ideals” (Columbia Spectator, June 8, 1978). In 1986, the University of California sold $3 billion in South Africa-related stocks, the largest public institution to do so.

In 1990, South African President de Klerk began negotiations to end Apartheid. By 1993 it had been largely dismantled and the next year universal suffrage in South Africa led to the election of Nelson Mandela. Desmond Tutu recently said that “We could not have achieved our freedom and just peace without the help of people around the world, who through the use of non-violent means, such as boycotts and divestment, encouraged their governments and other corporate actors to reverse decades-long support for the Apartheid regime.” Two of the largest American investors in South Africa at the time of the divestment movement were U.S. oil companies Mobil and Caltex (a joint venture of Chevron and Texaco.)

Apartheid was not the only cause over which academic institutions and others have divested. Some, including Harvard and Haverford, CCNY and the University of California, as well as foundations, health organizations, insurance companies, and pension funds, sold their stock in tobacco companies. As Harvard president Derek Bok explained in 1990, the university did so because it did not want “to be associated with companies [whose] products create a substantial and unjustifiable risk of harm to other human beings.”

Today, scientists and many others recognize global warming as a far greater threat than Apartheid or smoking. According to award-winning Ohio State climatologist Lonnie Thompson, “virtually all of us are now convinced that global warming poses a clear and present danger to civilization.”

Students and others, frustrated by science denial and inaction in Washington, have begun to urge colleges to sell their stock in fossil fuel companies. Here are ten objections global warming activists are apt to hear from trustees and college administrators, with my responses.

1. “Scientists disagree as to whether global warming is even real.” Among 33,700 authors of peer-reviewed scientific articles on global warming published between 1991 and November 2012, many of them scientists at American universities, only about one author in a thousand rejects human-caused global warming.

2. “Global warming is not a moral issue like Apartheid.” Apartheid was immoral because a class of better-off whites oppressed poor blacks. Global warming is immoral because the third world countries and foundering island nations who are the least responsible will suffer the most. Colleges who showed enough concern for Africans to divest over Apartheid should recognize that global warming is likely already worsening drought and famine in East Africa. Climate models project a future of increasing drought over most of Africa, southern Europe and the Middle East, most of the Americas, Australia, and Southeast Asia.

3. “Global warming is not a health issue like smoking.” A recent study in Health Affairs analyzed the health costs of six “climate change–related events” in the U.S. between 2001 and 2009. The events included ozone pollution, heat waves, hurricanes, infectious disease outbreaks, river flooding, and wildfires. The six accounted for $14 billion in lost lives and health costs (Knowlton et. al, Health Affairs, November 2011 vol. 30, 2167-2176). According to a study published in the medical journal Lancet: “Climate change is the biggest global health threat of the 21st century.” The lead author of the study said, “The impacts will be felt all around the world – and not just in some distant future but in our lifetimes and those of our children.”

4. “Colleges have no direct interest in preventing global warming.” Unlike Apartheid, global warming is already affecting colleges and students directly. The AAUP says that Hurricane Katrina caused “undoubtedly the most serious disruption of American higher education in the nation’s history.” Hurricane Sandy closed dozens of colleges and according to CNN, affected an estimated 1.2 million students. Even if scientists are unsure exactly how much global warming contributed to Katrina and Sandy—not whether they contributed—those two storms and other recent extreme weather events offer an ominous portent of what lies ahead. Colleges will not be immune from the coming heat, wildfire, drought, megastorms, and sea level rise. Today’s college graduates and their children and grandchildren will have to live in the greenhouse world that we are knowingly creating.

5. “We do not invest or divest for social causes.” But colleges did divest over Apartheid, selling their stock in oil companies doing business in South Africa. Harvard, for example , sold Mobil, Shell, and Texaco. Thus the question is not whether a college will divest from fossil fuel companies, but when divestment is justified. By threatening human health and even the future of civilization, global warming is a worse evil than Apartheid and a far greater danger than smoking.

6. “Our sole endowment objective is to maximize investment return.” The overriding obligation of those responsible for a college endowment is to ensure that future student generations benefit to the same relative extent as the current generation. Trustees achieve this balance by adjusting how much of endowment earnings they spend each year and how much they reinvest. But global warming puts a new slant on the matter. By investing in fossil fuel companies, colleges are using their current financial resources in a way that jeopardizes the quality of life of their future alumni. By any reasoned and humane interpretation, this violates colleges’ professed commitment to intergenerational equity.

7. “Selling stock in fossil fuel companies will lower investment return and cause the college to have to make significant budget cuts.” This is the same argument that some colleges made when faced with the issue of divesting over Apartheid, yet many went ahead and found little financial effect. One academic study from 1986 found that “Historical returns since 1959 indicate that the South Africa-free portfolio, diluted with Treasury bills to bring its risk in line with the NYSE, would have outperformed the NYSE by 0.187 per cent annually. ” (Financial Implications of South African Divestment, Blake R. Grossman and William F. Sharpe, Financial Analysts Journal, Vol. 42, No. 4 (Jul. – Aug., 1986), pp. 15-29.) When a college sells stock it has the exact same amount of cash as the market value of the stock at the time of sale, minus transaction costs (estimated at 0.4% in the study of South African divestment), and can reinvest that money. The immediate financial consequences are small and phasing in divestment over several years would ameliorate the long term consequences.

8. “Divestment is controversial and would hurt future fundraising.” Colleges did not let the fear of controversy stop them from divesting over Apartheid. Yes, donations from fossil fuel companies will decline, but gifts from donors who agree that global warming is a moral and a financial issue will rise, and there will be more of those donors. Colleges ought to do what is right, not what is expedient.

9. “Our most effective impact on climate change comes through our teaching, our research, and the careers of our alumni.” While colleges and universities have gone about their business during the second half of the twentieth century, CO2 emissions have risen by 40% over natural levels, enough to make a temperature rise of at least 2°C (3.6°F) during the rest of this century inevitable. In 2011, CO2 emissions rose by 3.2% to the highest level ever recorded. Business-as-usual by colleges has failed to curtail global warming and there is no reason to believe that more business-as- usual will produce a different result.

10. “Divestment won’t do any good.” It is true that divestment will have little financial impact on the fossil fuel companies. Instead, the impact will come from example and moral suasion. Divestment would have the benefit of asking colleges and their trustees, who include some of the most influential members of society, to address global warming and take a stand on an issue that directly affects colleges and their alumni. The publicity from a widespread divestment campaign would call attention to global warming and pressure fossil fuel companies to become part of the solution. In addition, divestment would provide colleges with the funds for a different type of investment. The top 500 colleges have over $400 billion in their endowments. Redirecting just 1% of that amount would free $4 billion for investment in companies that produce clean energy.

Humans have already emitted enough CO2 to ensure that global warming will not end in the lifetime of any person reading this essay. As the years and decades go by and its effects become ever more dire, global warming will grow into a perennial campus issue. It is not going away. Some colleges will take the lead and divest now; others will follow eventually. The question for each college is whether, on the most important issue of this century, it will be a leader or a follower.

To end as Elizabeth Kolbert ended her Field Notes from a Catastrophe, “It may seem impossible to imagine that a technologically advanced society could choose, in essence, to destroy itself, but that is what we are now in the process of doing.”

James Lawrence Powell was Acting President of Oberlin College, President of Franklin and Marshall College, President of Reed College, President of the Franklin Institute, and President of the Los Angeles County Museum of Natural History. Presidents Reagan and George H. W. Bush appointed him to the National Science Board, where he served for twelve years. He has a PhD from MIT and DSc degrees from Berea College and Oberlin College. He is the author of nine books. His most recent print book is The Inquisition of Climate Science (Columbia University Press). Powell currently serves as Executive Director of the National Physical Science Consortium.

I searched the Web of Science, an online science publication tool, for peer-reviewed scientific articles published between January first 1991 and November 9th 2012 that have the keyword phrases “global warming” or “global climate change.” The search produced 13,950 articles. See methodology.

I read whatever combination of titles, abstracts, and entire articles was necessary to identify articles that “reject” human-caused global warming. To be classified as rejecting, an article had to clearly and explicitly state that the theory of global warming is false or, as happened in a few cases, that some other process better explains the observed warming. Articles that merely claimed to have found some discrepancy, some minor flaw, some reason for doubt, I did not classify as rejecting global warming.

Articles about methods, paleoclimatology, mitigation, adaptation, and effects at least implicitly accept human-caused global warming and were usually obvious from the title alone. John Cook and Dana Nuccitelli also reviewed and assigned some of these articles; John provided invaluable technical expertise.

This work follows that of Oreskes (Science, 2005) who searched for articles published between 1993 and 2003 with the keyword phrase “global climate change.” She found 928, read the abstracts of each and classified them. None rejected human-caused global warming. Using her criteria and time-span, I get the same result. Deniers attacked Oreskes and her findings, but they have held up.

Some articles on global warming may use other keywords, for example, “climate change” without the “global” prefix. But there is no reason to think that the proportion rejecting global warming would be any higher.

By my definition, 24 of the 13,950 articles, 0.17 percent or 1 in 581, clearly reject global warming or endorse a cause other than CO2 emissions for observed warming. The list of articles that reject global warming is here.

The 24 articles have been cited a total of 113 times over the nearly 21-year period, for an average of close to 5 citations each. That compares to an average of about 19 citations for articles answering to “global warming,” for example. Four of the rejecting articles have never been cited; four have citations in the double-digits. The most-cited has 17.

Of one thing we can be certain: had any of these articles presented the magic bullet that falsifies human-caused global warming, that article would be on its way to becoming one of the most-cited in the history of science.

The articles have a total of 33,690 individual authors. The top ten countries represented, in order, are USA, England, China, Germany, Japan, Canada, Australia, France, Spain, and Netherlands. (The chart shows results through November 9th, 2012.)

Global warming deniers often claim that bias prevents them from publishing in peer-reviewed journals. But 24 articles in 18 different journals, collectively making several different arguments against global warming, expose that claim as false. Articles rejecting global warming can be published, but those that have been have earned little support or notice, even from other deniers.

A few deniers have become well known from newspaper interviews, Congressional hearings, conferences of climate change critics, books, lectures, websites and the like. Their names are conspicuously rare among the authors of the rejecting articles. Like those authors, the prominent deniers must have no evidence that falsifies global warming.

Anyone can repeat this search and post their findings. Another reviewer would likely have slightly different standards than mine and get a different number of rejecting articles. But no one will be able to reach a different conclusion, for only one conclusion is possible: Within science, global warming denial has virtually no influence. Its influence is instead on a misguided media, politicians all-too-willing to deny science for their own gain, and a gullible public.

Scientists do not disagree about human-caused global warming. It is the ruling paradigm of climate science, in the same way that plate tectonics is the ruling paradigm of geology. We know that continents move. We know that the earth is warming and that human emissions of greenhouse gases are the primary cause. These are known facts about which virtually all publishing scientists agree.

James Lawrence Powell is the author of The Inquisition of Climate Science. Powell is also the executive director of the National Physical Science Consortium, a partnership among government agencies and laboratories, industry, and higher education dedicated to increasing the number of American citizens with graduate degrees in the physical sciences and related engineering fields. This article is cross-posted with permission with the Columbia University Press blog.

This article is a cross-post with our partners at DeSmogBlog.

With Lance Armstrong retired and most of the other top riders expelled for illegal drug use, Landis had become one of the favorites. He was leading when in stage 16 he fell to eleventh place. Then, just as his chances of winning seemed dashed, Landis won the next stage going away and went on to ride the Champs-Élysées in the winner’s yellow jersey.

A few days later, Landis’s team announced he had failed a test for banned steroids. Landis appealed the ban, raised an estimated $1M for his defense, and wrote a 300-page book titled, “Positively False: the Real Story of how I won the Tour de France.”

After years of denial, in 2010 Landis reversed himself and admitted that from 2002 through 2006 he had used a grab-bag of banned substances and methods. Why did he finally have to give up his denial? Because the carbon isotope test proved beyond reasonable doubt that he had doped with synthetic testosterone.

Testosterone is mostly carbon. Synthetic testosterone is made entirely from plants, which have a different carbon isotope ratio than our environment overall. The carbon in Landis’s body had the distinctive plant ratio, proving beyond reasonable doubt that he had doped with synthetic testosterone.

So how do scientists use the method to confirm that humans are causing global warming?

Since 1800, CO2 in the earth’s atmosphere has risen 40% and because of the greenhouse effect, warmed the planet. The obvious source of the added carbon is the 330 billion tons of carbon that burning fossil fuels has added to the atmosphere since the Industrial Revolution. Yet global warming deniers deny this obvious fact. Well then, let’s prove it.

First, coal, oil, and natural gas also come from plants and also have the distinctive carbon isotope ratio of plants. As CO2 in the atmosphere has built up steadily, its isotopic composition has shifted just as steadily in the direction of plant carbon. That tells us the added carbon is coming from plants. But what kind of plants? That question we can also answer.

One carbon isotope, C14, is radioactive and dies away to undetectable levels in 50,000 years or so. Fossil fuels, being millions of years old, have no C14 left. Adding ancient carbon should have lowered the proportion of C14 in the atmosphere—and it has. For the last 50 years, as the amount of carbon in the atmosphere has increased, its C14 ratio has fallen steadily.

Just as the carbon isotopes prove that Landis doped his body, they prove beyond reasonable doubt that humans are doping the atmosphere with ancient plant carbon, carbon from fossil fuels.

Unlike people, isotopes do not lie.

James Lawrence Powell is the author of The Inquisition of Climate Science. Powell is also the executive director of the National Physical Science Consortium, a partnership among government agencies and laboratories, industry, and higher education dedicated to increasing the number of American citizens with graduate degrees in the physical sciences and related engineering fields. This article is cross-posted with permission with the Columbia University Press blog.

If by going dark for a day to protest pending anti-piracy legislation, Wikipedia and other sites can cause the US Congress to change course, could they do a sequel about something even more important, such as global warming? James L. Powell imagines how it could work.

April 22, 2012: Earth Day

Thousands of Internet sites are taking part in a “blackout” to protest the lack of government action to prevent dangerous global warming. The most prominent social networking and communication sites went down for 24 hours starting at midnight last night, showing a dark homepage and directing users to the protest movement’s central site.

Included were Facebook, Google, Tumblir, Twitter, Wikipedia and WordPress, which urged the owners of the 72 million sites that use its service to join. Wikipedia founder Jimmy Wales said, “A few months ago we went dark to protest legislation that the U.S. Congress was considering that would fatally damage the free and open Internet.” He continued, “But something much more important than the Internet is at stake: the future of humanity.” Twitter CEO Dick Costelo said, “We declined to join the earlier protest because we thought it was foolish to close a global business in reaction to single-issue national politics. But global warming threatens all businesses and all peoples.” He summed up, “Twitter is in.”

By the end of the day, President Barack Obama, surrounded by the senior members of his party and a surprising number of Republicans, told the press that, “Our society cannot function without the Internet and it cannot function for long with global warming. It is time for reason and scientific knowledge to direct congressional action to curb carbon emissions and put the world on track to limit global temperature rises to 2°C.” The president went on, “Everyone who has children and grandchildren should demand that their elected representatives act and act now.”

Many dark US sites urged visitors to call their Congressional Representative, providing the name and number. Techfleece.com went further by offering to call a visitor, provide talking points, and connect the visitor with his or her member of Congress.

Congressional telephone lines and e-mail servers were jammed as millions joined the protest. Following President Obama’s press conference, Republican Leaders Mitch McConnell (R-KY) and John Boehner (R-OH) jointly pledged to take up action to curb carbon emissions as their highest priority.

The protest site asked each member of Congress to take the following pledge: “I accept the findings of the US Academy of Sciences that ‘Climate change is occurring, is caused largely by human activities, and poses significant risks for a broad range of human and natural systems.’” By the end of the day, every Democrat and many Republicans had signed the pledge and the number was growing hourly.

Many university sites joined in the blackout, including MIT, Oxford, Stanford, and the University of Queensland. Scientific journals including Science Magazine and Nature also went dark. Shutting down for the day were the British House of Commons and the German Bundestag.

Many climate blogs joined the Day of Darkness, including RealClimate.org, ScienceProgress.org, and SkepticalScience.com.

Noted climate scientist James Hansen, who has been arrested for joining protests against carbon polluters, said, “This may be humanity’s last chance.”

Dr. James Powell is a geochemist and author who formerly served as president of Reed College and for 12 years on the National Science Board.

Part 1 in this series introduced a database of global warming skeptics and the number of peer-reviewed papers each has published. Part 2 examined the “takeaways” from these papers.

To generate these lists we identified some 120 global warming skeptics, searched the Web of Science for their peer-reviewed papers, then read the abstracts and sometimes the entire paper to flag those that denied or attempted to cast substantial doubt on human-caused global warming. (This study differs from the one by Oreskes (2004) who did not count papers that “cast substantial doubt.”)

We have now sorted the papers by argument and by year. The list sorted by argument has links to the rebuttals, allowing these conclusions:

• The principal claim of each of these arguments has been thoroughly rebutted in the scientific literature, as summarized on Skeptical Science here.
• Some of the arguments that rank highly by popularity are conspicuous by their absence among the skeptic papers ranked by Skeptical Science. None argues that (1) climate’s changed before, (4) there is no consensus, (8) animals and plants can adapt, (9) it hasn’t warmed since 1998, (10) ice age predicted in the 70s, (11) Antarctica is gaining ice, or (12) CO2 lags temperature. Global warming skeptics continue to make these arguments at every opportunity, but demonstrably it is not possible to back up any of them with evidence that will pass peer-review. Until there is such evidence, there is no reason anyone should pay attention to these unsupported and misleading claims.

To reiterate the principal conclusions of this series:

• 70% of the global warming skeptics identified, including some of the most outspoken, have no scientific publications that deny or cast substantial doubt on global warming.
• None of the papers provides the “killer argument,” the one devastating fact that would falsify human-caused global warming.
• Each skeptic argument has been debunked in other peer-reviewed papers.
• The skeptics have no plausible theory to explain the observed global warming.
• Even though the evidence for human-caused global warming and the scientific consensus have grown stronger, no skeptic who wrote in the first half of the 1990s has recanted. To be a climate skeptic is to remain a skeptic.

The answer to the question of this series is resounding no: there is no case against human-caused global warming in the peer-reviewed literature.

Dr. James Powell is a scientist, author, former president of Reed College, and was appointed by two different presidents to the National Science Board.

Science advances through the peer-reviewed primary literature. Peer-review is not perfect, but it is the best system humans have invented for uncovering and correcting errors. In science, the truth will out.

Part 1 of this series of posts introduced a database of more than 115 climate skeptics and the peer-reviewed papers each has published as recorded in the Web of Science. The database is located here. I have now added the journal for each publication. You will find the papers organized by journal here.

Some conclusions emerge from reading this set of abstracts, and in some cases the entire paper, which can be done in an hour or two.

• 70% of those listed have no scientific publications that deny or cast substantial doubt on global warming. This list includes such outspoken and media-promoted skeptics as Joe Bastardi, Freeman Dyson, Bjorn Lomborg, Christopher Monckton, Jo Nova, Ian Plimer, Matt Ridley, and S. Fred Singer. Why don’t they write up their argument and submit it to a scientific journal?
• None of the papers provides the “killer argument,” the one devastating fact that would falsify human-caused global warming. The best they can do is claim that sensitivity is low, which they have been unable to substantiate and which much evidence contradicts. If as the skeptics claim, human-caused global warming is wrong, why can’t they show it is wrong?
• None of the papers explains the observed, concomitant rise in fossil fuel emissions, atmospheric CO2, and global temperatures. Attempts in some papers to blame the the sun are falsified because as temperature has risen, solar activity has remained about the same, or even declined.
• The skeptics have no better theory, or indeed any theory, to explain all of the observational evidence of man-made global warming.
• Many papers, particularly the earlier ones, suggest improvements in the IPCC’s procedures, in the way temperature data are collected, etc. They imply that once those improvements have been made, the case for human-caused global warming might be weakened. Instead that case has grown stronger.
• A true scientific skeptic must be prepared to change his or her mind as new evidence comes in. But as far as I am able to tell from these papers, in spite of the continuing rise in global temperature; heat records; extreme weather of all sorts; melting glaciers, ice caps, and sea ice; sea level rise; migrating species, and the like, no skeptic who wrote in the first half of the 1990s has since accepted human-caused global warming. To be a climate skeptic is to remain a skeptic.
• Richard Muller says, “The skeptics raised valid points and everybody should have been a skeptic two years ago. And now we have confidence that the temperature rise that had previously been reported had been done without bias.” To me, this makes him a skeptic. See this other quotes here.  But his publication of the BEST results may indicate that we should no longer consider him one.
• In a 1990 paper, Professor Richard Lindzen of MIT argued that because the observed global temperature rise to that year had been less than predicted, the sensitivity of global temperature to rising CO2 must be less than expected. Therefore, he wrote in 1990, “The current state of our understanding of climate hardly justifies a consensus over the response of climate to the small increase in downward flux caused by a doubling of CO2.” In spite of all the evidence mentioned in item 6, 21 years later, in a paper titled, “On the observational determination of climate sensitivity and its implications,” Lindzen and Choi conclude, “The results imply that the models are exaggerating climate sensitivity.” In that 21 year period, atmospheric CO2 concentration rose from 354 to 389 ppm and the global mean temperature anomaly rose from about +0.2 to about +0.6°C. Moreover, if the sensitivity is as low as Lindzen has been saying for more than two decades, what caused the observed temperature rise?
• Skeptics feel no compunction about making emphatic statements on subjects far afield from their expertise, in some cases, literally. Astrophysicists write about polar bears; those with no expertise in computer modeling denounce  climate models.

These peer-reviewed papers by skeptics offer no reason to doubt that global warming is real, caused by humans, and dangerous. Despite ample opportunity, climate skeptics have failed to present any coherent alternative to the theory that carbon emissions are the primary driver of observed warming. That is why 100 national and international scientific organizations have issued statements accepting human-caused global warming, and not a single such organization has issued a statement of denial.

Dr. James Powell is a scientist, author, former president of Reed College, and a member of the National Science Board.

In this piece, Dr. Powell investigates the most prominent climate deniers to see how many of them have actually ever published peer-reviewed papers about climate science. For a more comprehensive look at the scientific literature for and against, also see Skeptical Science’s cool interactive graphic. What follows is an edited cross-post by Dr. Powell from our partners at Skeptical Science.

Few climate deniers conduct or publish scientific work

Science progresses through the peer-reviewed literature. Unless an idea, theory, or interpretation is reported in a peer-reviewed journal, it is just someone’s unsubstantiated opinion. Publication in a peer-reviewed journal does not ensure that an author’s arguments will stand the test of time, but rather that they have been scrutinized by experts and judged to represent a contribution to science that others in the field can benefit from knowing about.

Climate skeptics give the impression that there is a substantial case against human-caused global warming. But is it true?

One way to shed light on the question is to review the peer-reviewed literature, as Naomi Oreskes did in her classic article [Science 306, p. 1686, 2004; see http://sks.to/oreskes.] She searched papers written between 1993 and 2003 for the keywords “global climate change.” She turned up 928 papers, read each abstract, and judged that none “reject[ed] the consensus position” that humans are causing global warming.

Instead of starting with the literature, I began with a list of over 100 skeptics who have or give the impression they have scientific expertise. For example, Christopher Monckton, despite his lack of scientific credentials, gives talks in which he takes on the guise of a scientist. Anthony Watts, a former TV meteorologist, blogs about complicated scientific matters. George Will, in contrast, while acting as though he knows more than scientists, does not pretend to be one. I include Monckton and Watts, but not Will.

I searched the Web of Science, or WOS, which covers more than 8,000 peer-reviewed journals, for each skeptic by name, being careful to include variations in the spelling of the first name. I counted only primary articles; no book reviews, review articles, comments, replies to previously published papers, speeches, presentations, conference summaries, etc. I searched for articles classified by the WOS as “Meteorology Atmospheric Sciences.”

I read the abstract and sometimes the conclusions of each article. If an article takes a negative or explicitly doubtful position on human-caused global warming, I included it. I did not include papers that propose some improvement in methodology but go no further.

Click the image to zoom in on the denier database.

To use the database, first click here, then click on a name to bring up a list of that skeptic’s publications arranged chronologically. By hovering the cursor over the link, you can read an excerpt from the abstract or in some cases the entire abstract. Click on the link and you will be taken to the article itself or to the abstract, if there is one.

Note that some skeptics tend to publish with others: Baliunas with Soon; Balling with the Idsos; etc. So the total number of papers is somewhat less than the total obtained from adding the numbers for each skeptic. Also note that several skeptics have published in Energy & Environment. The WOS includes only some of these papers, perhaps because somewhere along the line, the journal changed its review practices. I include any papers from E&E that come up in the WOS.

Admittedly, my list is subjective. I wanted to count papers that a reasonable person might conclude undercut human-caused global warming, erring on the side of inclusion. I will be happy to consider any skeptic, paper, or correction that readers suggest. This is a work in progress.

Some examples may help:

Because it appeared to cast doubt on the premises of human-caused global warming and the work of the IPCC, I counted a paper by R. A. Pielke, Sr. (2002) which concluded, “Unless it can be shown that land cover change and biogeochemical effects on the regional and global climate systems are insignificant relative to the radiative effect of a doubling of CO2, the IPCC and U.S. National Assessment reports are, therefore, summaries of sensitivity only.”

I counted a paper by Curry (2011) whose abstract reads in its entirety,”This paper argues that the IPCC has oversimplified the issue of uncertainty in its Assessment Reports, which can lead to misleading overconfidence. A concerted effort by the IPCC is needed to identify better ways of framing the climate change problem, explore and characterize uncertainty, reason about uncertainty in the context of evidence-based logical hierarchies, and eliminate bias from the consensus building process itself.” Her claim that bias colors our understanding appeared to me to be an attempt to call human-caused global warming into question.

I did not count a paper by Klotzbach et al. (2009) titled, “An alternative explanation for differential temperature trends at the surface and in the lower troposphere,” which concluded, “The differences between trends observed in the surface and lower-tropospheric satellite data sets are statistically significant in most comparisons, with much greater differences over land areas than over ocean areas. These findings strongly suggest that there remain important inconsistencies between surface and satellite records.” This paper suggests we have a way to go in our understanding of surface and satellite temperatures, but does not go so far as to imply that once we have that understanding, human-caused global warming will be called into question.

I did not count a paper by Fall et al. (2011) titled, “Analysis of the impacts of station exposure on the US Historical Climatology Network temperatures and temperature trends,” whose abstract concluded, “Comparison of observed temperatures with NARR shows that the most poorly sited stations are warmer compared to NARR than are other stations, and a major portion of this bias is associated with the siting classification rather than the geographical distribution of stations. According to the best-sited stations, the diurnal temperature range in the lower 48 states has no century-scale trend.” This paper did not seem to cross the line to suggest explicitly that poor station siting might have given the false impression that global warming is real.

The point of this exercise is not just the number of papers, but what they say and whether they make a case against human-caused global warming. In part two, I offer what I regard as the “takeaways” from these papers.

Part two of this series can be viewed here. For more great coverage and useful tools for climate science advocates, visit Skeptical Science.