Wibjorn Karlen

Wibjorn Karlen


  • Ph.D., professor emeritus of physical geography and quaternary geology.


Karlen is a retired professor in the department of Physical Geography and Quaternary Geology from Stockholm University.

Karlen appears as on Senator James Inhofe‘s list of scientists who are skeptical of global warming as one of 40 who are currently retired.

Stance on Climate Change

“Newspapers should think about the damage they are doing to many persons, particularly young kids, by spreading the exaggerated views of a human impact on climate. As far as I can see the IPCC ‘Global Temperature’ is wrong. Temperature is fluctuating but it is still most places cooler than in the 1930s and 1940s. It will take about 800 years before the water level has increased by one” meter.”1Editorial: Global warming ‘consensus’ a fiction,” The Orange County Register, January 1, 2008.

Key Quotes

“By relying on statistical reconstruction of the last 1000 years, using only the temperature patterns of the last 140 years instead of actual temperature readings, the IPCC report and Summary missed both a major cooling period as well as a significant warming trend during that millennium, said Karlen.

“’The [IPCC report] relies extensively on an attempt to reconstruct the global climate during the last 1000 years,’ said Karlen. ‘This reconstruction shows neither a Medieval Warm Period nor a Little Ice Age. But extensive evidence shows that both these events occurred on a global scale and that climates fluctuated significantly.’”2 Bruce Sullivan. “SCIENTISTS SAY GLOBAL WARMING THEORY IS A LOT OF HOT AIR,” Science and Environmental Policy Project, MAy 30, 2000. Archived March 25, 2007.

Key Deeds

February 4, 2018

In January 2018, more than 200 scientists endorsed an open letter calling on the American Museum of Natural History (AMNH) to remove climate change denier Rebekah Mercer from its board and to “end ties to anti-science propagandists and funders of climate science misinformation.” The New York Times reported that those among the AMNH letter calling for Mercer to step down were Michael E. Mann, director of the Earth System Science Center at Pennsylvania State University, and Katharine Hayhoe, director of the Climate Science Center at Texas Tech University.3 Robin Pogrebin and Somini Sengupta. “A Science Denier at the Natural History Museum? Scientists Rebel,” The New York Times, January 25, 2018. Archived February 13, 2018. Archive.is URL: https://archive.is/tAIv4

Karlen was among a group of climate change deniers who responded with their own open letter, calling for the AMNH “not to cave in to this pressure.” The letter was signed by numerous individuals with ties to groups funded by the Mercer Family Foundation such as Will Happer of the CO2 CoalitionRichard Lindzen, a fellow at the Cato InstituteCraig Idso, the chairman of the Center for the Study of Carbon Dioxide and Global Change. There are a number of signatories affiliated with the Heartland Institute, which has received over $5.78 million from the Mercer Family Foundation since 2008.4 Graham Readfearn. “Climate Science Deniers Defend New York’s American Museum of Natural History From Calls to Drop Trustee Rebekah Mercer,” DeSmog, February 6, 2018.

The letter reads:5 mnh18-feb4-petitionletter (PDF – Untitled). Retrieved from Watts Up With That.

“The Earth has supported abundant life many times in the geological past when there were much higher levels of carbon dioxide in the atmosphere. It is quite likely that future generations will benefit from the enrichment of Earth’s atmosphere with more carbon dioxide.

“Make no mistake, the agitators are not defending science from quackery — quite the contrary!”

February 23, 2017

Wibjorn Karlen was a signatory of a petition (PDF) organized by Richard Lindzen of the Cato Institute urging President Donald Trump to pull the United States out of the United Nations international convention on climate change (UNFCCC).6 “PETITION” (PDF), February 23, 2017. Richard Lindzen. PDF Archived at DeSmog.

“In just a few weeks, more than 300 eminent scientists and other qualified individuals from around the world have signed the petition below,” Lindzen wrote in the letter.7 “PETITION” (PDF), February 23, 2017. Richard Lindzen. PDF Archived at DeSmog.

DeSmog investigated the list, and found that only a small handful of the signatories could be considered “even remotely ‘qualified’ or ‘eminent’ — but not in the field of climate science.” The list included individuals “interested in climate,” and one signatory who only identified as an “emailer who wished to sign the petition” while some signers provided no affiliation or address whatsoever.8 Graham Readfearn. “Climate Science Denier Richard Lindzen’s List of 300 “Scientists” Sent to Trump Is the Usual Parade of Non-Experts,” DeSmog, February 27, 2017.

August 2016

Wibjorn Karlen is listed as a “Founding Member” of group named Climate Exit (Clexit) led by climate change denier Christopher Monckton. According to Clexit’s founding statement (PDF), “The world must abandon this suicidal Global Warming crusade. Man does not and cannot control the climate.”9The Clexit Committee comprises” (PDF), Clexit.net. Archived.pdf on file at Desmog. 10 “After Brexit, Clexit” (PDF), Clexit.net. Archived .pdf on file at Desmog.

Desmog reports on how the group grew in the wake of the UK’s decision to leave the EU. A key member of Clexit’s “60 well-informed science, business and economic leaders” is Hugh Morgan, a former board member of the Reserve Bank of Australia and former CEO of Western Mining Corporation with close ties to Australia’s Liberal party.11 Graham Readfearn. “After Brexit, Climate Science Denialists Form New Group to Call for a Clexit,” Desmog, August 3, 2016. 12Hugh Morgan AO,” Australian Government Department of Foreign Affairs and Trade. Archived February 22, 2002. Archive.is URL: https://archive.is/1ObOB

According to Clexit’s founding statement:

“If the Paris climate accord is ratified, or enforced locally by compliant governments, it will strangle the leading economies of the world with pointless carbon taxes and costly climate and energy policies, all with no sound basis in evidence or science […]”13 “After Brexit, Clexit” (PDF), Clexit.net. Archived .pdf on file at Desmog.

April, 2009

Karlen’s name appeared in an advertisement published by the Cato institute published an advertisement in major newspapers including the Washington Post, the New York Times, the Washington Times, and the Los Angeles Times that questioned President Obama’s stance on climate change.14 With all due respect…” RealClimate, March 24, 2009.

The add received critiques from numerous sources and the New York Times ad alone reportedly cost at least $150,000.15 Jonathan Hiskes. “Cato’s skeptic ads draw a flurry of responses,” Grist, April 2, 2009.

PolitiFact also evaluated Cato’s claim that “There has been no global warming for a decade now,” and found it to be false.

March 4, 2008

Karlen signed the 2008 Manhattan Declaration on Climate Change which was presented for consideration at the Heartland Institute’s 2008 International Conference on Climate Change.16CLIMATE EXPERTS WHO SIGNED MANHATTAN DECLARATION,” International Climate Science Coalition. Accessed January, 2012.

Created by the International Climate Science Coalition (ICSC)—a group of climate skeptics directed by Tom Harris—the declaration concludes that “attempts by governments to legislate costly regulations on industry and individual citizens to encourage CO2 reduction will slow development while having no appreciable impact on the future trajectory of global climate change.”

January 2, 2008

Karlen’s name appears on the Lavoisier Group‘s submission to the Garnaut Climate Change Review. One of their first assertions is that “There is no scientific consensus on the causal connection between anthropogenic carbon dioxide and global climate control. The weight of genuinely reputable scientific opinion is now firmly against any such connection.”

Their advice to the government is to “Wait and See” because “We do not know what the
climatic future is…”17 “Submission from the Lavoisier Group to the Garnaut Climate Change Review: Issues Paper 1 Climate Change: Land use – Agriculture and Forestry” (PDF) The Lavosier Group, January 2, 2008.

February 5, 2007

Was listed as an “author” of the Fraser Institute’s Independent Summary for Policymakers which concludes that “There is no compelling evidence that dangerous or unprecedented changes [in climate] are underway.”

The report was coordinated by Ross McKitrick and the writing team included numerous global warming deniers such as Joseph D’Aleo, Madhav Khandekar, William Kininmonth, Christopher Essex, Ian Clark, Tad Murty, and James J. O’Brien.

The Fraser Institute is a Canadian “think” tank that has received $120,000 in funding from ExxonMobil between 2003 and 2004.

December 13, 2007

Karlen signed a 2007 open letter to the Secretary-General, along with another “100 prominent scientists,” which declared that the “UN Climate Conference [is] taking the world in entirely the wrong direction.”

The letter proclaims that CO2 is a “non-polluting gas that is essential to plant photosynthesis” while the “IPCC’s conclusions are quite inadequate as justification for implementing policies that would markedly diminish future prosperity.”18Open Letter to the Secretary-General of the United Nations,” December 13, 2007. Reprinted by the Science and Public Policy Institute. Archived July 23, 2011.

April 2006

Karlen was a signatory to the 2006 open letter to Prime Minister Stephen Harper, titled “Open Kyoto to Debate,” which urged inaction on climate policy while denying the reality of climate change.19 Open Kyoto to debate,” National Post, April 11, 2006. Archived April 12, 2011.

May 2000

Karlen was part of a group assembled by Science and Environmental Policy Project (SEPP) created to critique the IPCC’s third assessment report (TAR). SEPP is headed by the prominent denier Fred Singer and has received at least $20,000 from ExxonMobil between 1998 and 2000, as well as funding from Shell and Uniroyal.20What’s wrong with U.N. climate science: An independent scientific review of the IPCC’s Third Assessment Report,” (News Release) The Science and Environmental Policy Project, May 25, 2000. Archived February 15, 2007.

The group contained 14 unnamed “climate scientists” that made up SEPP’s “Science Integrity Team.” The team set out to present its findings “in plain English” to congress and the media—findings which suggested a lack of significant or human-caused global warming.

Their findings were summarized as follows:

  • “The earth’s atmosphere has not warmed over the past 20 years.”
  • “The last century is not the warmest in the last 1000 years.”
  • “Man’s use of fossil fuels has not had a perceptible effect on global climate.”
  • “Even if the earth were to warm slightly, and atmospheric CO2 were to increase, the effects would be mostly beneficial.”
  • “The only support for serious future warming comes from theoretical climate models – but they give only imperfect simulations of the real atmosphere, are not validated by actual observations, and are incapable of making valid predictions.”



A search of 22,000 academic journals shows that Karlen has published over 40 peer-reviewed articles.

Other Resources


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