Editing Richard Lindzen (section)

== Final period (1990–2010) ==

===Climate sensitivity===
Lindzen hypothesized that the Earth may act like an [[Iris hypothesis|infrared iris]]. A [[sea surface temperature]] increase in the tropics would result in reduced [[cirrus cloud]]s and thus more [[infrared radiation]] leakage from Earth's atmosphere.{{Sfn | Lindzen | Chou | Hou | 2001}} Additionally, rising temperatures would cause more extensive drying due to increased areas of [[subsidence (atmosphere)|atmospheric subsidence]]. This hypothesis suggests a negative feedback which would counter the effects of {{CO2}} warming by lowering the [[climate sensitivity]]. Satellite data from [[Clouds and the Earth's Radiant Energy System|CERES]] has led researchers investigating Lindzen's theory to conclude that the Iris effect would instead warm the atmosphere.<ref>{{cite journal | first1=Bing | last1=Lin | title = The iris hypothesis: a negative or positive cloud feedback? | journal=Journal of Climate | year=2002 | volume=15 | issue=1 | pages=3–7 | bibcode=2002JCli...15....3L | doi = 10.1175/1520-0442(2002)015<0003:TIHANO>2.0.CO;2|display-authors=etal| doi-access=free }}</ref><ref name="NASA satellite instrument warms up global cooling theory">{{cite press release | url = http://www.nasa.gov/centers/langley/news/releases/2002/02-005.html | title=NASA satellite instrument warms up global cooling theory | first1 =Chris | last1 = Rink | first2 = Julia | last2 = Cole | publisher=[[NASA]] | date=January 16, 2002}}</ref> Lindzen disputed this, claiming that the negative feedback from high-level clouds was still larger than the weak positive feedback estimated by Lin et al.<ref>{{cite journal | first1=Ming-Dah | last1=Chou | first2=Richard S. | last2=Lindzen | first3 = Arthur Y.  | last3=Hou | title=Comments on "The Iris Hypothesis: A Negative or Positive Cloud Feedback?" | journal=Journal of Climate | year=2002 | volume=15 | issue= 18 | pages= 2713–15 | bibcode= 2002JCli...15.2713C | doi = 10.1175/1520-0442(2002)015<2713:COTIHA>2.0.CO;2| citeseerx=10.1.1.232.8350 }}</ref>

Lindzen has expressed his concern over the validity of [[climate model|computer models]] used to predict future climate change. Lindzen said that predicted warming may be overestimated because of their handling of the climate system's [[water vapor feedback]]. The feedback due to water vapor is a major factor in determining how much warming would be expected to occur with increased atmospheric concentrations of [[carbon dioxide]], and all existing computer models assume positive feedback — that is, that as the climate warms, the amount of water vapour held in the atmosphere will increase, leading to further warming. By contrast, Lindzen believes that temperature increases will actually cause more extensive drying due to increased areas of [[subsidence (atmosphere)|atmospheric subsidence]] as a result of the Iris effect, nullifying future warming.<ref name = stevenswnyt>{{cite news | last =Stevens | first = William K. | date=June 18, 1996 | title=Scientist at work: Richard S. Lindzen; A Skeptic Asks, Is It Getting Hotter, Or Is It Just the Computer Model? | url= https://www.nytimes.com/1996/06/18/science/scientist-work-richard-s-lindzen-skeptic-asks-it-getting-hotter-it-just-computer.html?pagewanted=1 | work =The New York Times | access-date=May 22, 2010}}</ref> This claim was criticized by [[climatologist]] [[Gavin Schmidt]], Director of [[NASA]]'s [[Goddard Institute for Space Studies]], who notes the more generally-accepted understanding of the effects of the Iris effect and cites empirical cases where large and relatively rapid changes in the climate such as [[El Niño]] events, the [[Ultra-Plinian]] [[1991 eruption of Mount Pinatubo|eruption of Mount Pinatubo in 1991]], and recent trends in global temperature and water vapor levels show that, as predicted in the generally-accepted view, water vapor increases as the temperature increases, and decreases as temperatures decrease.<ref name=GSchmidtContraLindzen>{{cite web | last = Schmidt | first = Gavin | date= February 14, 2006 | title=Richard Lindzen's HoL testimony | url=http://www.realclimate.org/index.php/archives/2006/02/richard-lindzens-hol-testimony/ | publisher=Real Climate}}</ref>

Contrary to the [[IPCC Third Assessment Report|IPCC's assessment]] in 2001, Lindzen said that climate models are inadequate. Despite accepted errors in their models, e.g., treatment of clouds, modelers still thought their climate predictions were valid.<ref name= guterlfnewsweek>{{cite magazine | last =Guterl | first = Fred | date=July 23, 2001 | title=The Truth About Global Warming | url=http://www.newsweek.com/id/78772/page/1 | magazine=Newsweek | access-date=2009-07-26}}</ref> Lindzen has stated that due to the non-linear effects of carbon dioxide in the atmosphere, CO<sub>2</sub> levels are now around 30% higher than pre-industrial levels but temperatures have responded by about 75% {{convert|0.6|C-change|2|abbr=on}} of the expected value for a doubling of CO<sub>2</sub>. The IPCC (2007) estimates that the expected rise in temperature due to a doubling of CO<sub>2</sub> to be about {{convert|3|C-change|abbr=on}}, ± 1.5°. Lindzen has given estimates of the Earth's climate sensitivity to be 0.5&nbsp;°C based on ERBE data.<ref name=erbe>{{cite journal | first1=Richard S. | last1=Lindzen | title=On the determination of climate feedbacks from ERBE data | journal=Geophysical Research Letters | year=2009 | volume=36 | issue=16 | pages=L16705 | bibcode=2009GeoRL..3616705L | doi=10.1029/2009GL039628 | display-authors=etal | doi-access=free }}</ref> These estimates were criticized by [[Kevin E. Trenberth]] and others,<ref>{{cite web |title=Working out climate sensitivity from satellite measurements |url=http://www.skepticalscience.com/Lindzen-Choi-2009-low-climate-sensitivity.htm |author=dana1981 |date=July 6, 2012 |work=Skeptical Science |access-date=December 20, 2022}}</ref> and Lindzen accepted that his paper included "some stupid mistakes". When interviewed, he said "It was just embarrassing", and added that "The technical details of satellite measurements are really sort of grotesque." Lindzen and Choi revised their paper and submitted it to ''[[Proceedings of the National Academy of Sciences of the United States of America|PNAS]]''.<ref name="www.nytimes 120501">{{cite news  | last = Gillis | first = Justin | title = Clouds' Effect on Climate Change Is Last Bastion for Dissenters  | url = https://www.nytimes.com/2012/05/01/science/earth/clouds-effect-on-climate-change-is-last-bastion-for-dissenters.html?pagewanted=3&_r=3& | newspaper =  New York Times | date = May 1, 2012 | access-date = January 24, 2014 }}</ref> The four reviewers of the paper, two of whom had been selected by Lindzen, strongly criticized the paper and PNAS rejected it for publication.<ref>{{Cite web | last = Schekman | first = Randy | author-link = Randy Schekman | title = Title: On the observational determination of climate sensitivity and its implications Ms. No.: 2010-15738 | url = http://www.masterresource.org/wp-content/uploads/2011/06/Attach3.pdf | publisher = PNAS Office | date = January 19, 2011 | access-date = January 24, 2014 | url-status = dead | archive-url = https://web.archive.org/web/20120619054256/http://www.masterresource.org/wp-content/uploads/2011/06/Attach3.pdf | archive-date = June 19, 2012 | df = mdy-all }}</ref> Lindzen and Choi then succeeded in getting a little known Korean journal to publish it as a 2011 paper.<ref name="www.nytimes 120501" /><ref>{{Cite journal | first1 = Richard S. | last1=Lindzen | first2=Yong-Sang  | last2=Choi | title=On the observational determination of climate sensitivity and its implications | journal=Asia-Pacific Journal of the Atmospheric Sciences | year=2011 | volume=47 | issue=4 |pages=377–390 | bibcode = 2011APJAS..47..377L | doi= 10.1007/s13143-011-0023-x| citeseerx=10.1.1.167.11 | s2cid=9278311 }}</ref> [[Andrew Dessler]] published a paper which found errors in Lindzen and Choi 2011, and concluded that the observations it had presented "are not in fundamental disagreement with mainstream climate models, nor do they provide evidence that clouds are causing climate change. Suggestions that significant revisions to mainstream climate science are required are therefore not supported."<ref>{{Cite journal | doi = 10.1029/2011GL049236| title = Cloud variations and the Earth's energy budget| year = 2011| last1 = Dessler | first1 = A. E.| journal = Geophysical Research Letters| volume = 38| issue = 19| pages = n/a|bibcode = 2011GeoRL..3819701D | citeseerx = 10.1.1.362.5742| s2cid = 17463106}}</ref>

===NAS panel===
In 2001, Lindzen served on an 11-member panel organized by the [[United States National Academy of Sciences|National Academy of Sciences]].<ref>{{cite web | title = Climate Change Science: An Analysis of Some Key Questions: Committee on the Science of Climate Change | url=http://www.nap.edu/html/climatechange/committee.html | publisher =[[National Academies Press]] | year=2001 | access-date=2007-04-05}}</ref> The panel's report, titled ''Climate Change Science: An Analysis of Some Key Questions'',<ref>{{cite book | title=Climate Change Science: An Analysis of Some Key Questions | url=http://www.nap.edu/catalog/10139.html?onpi_webextra6 | publisher = [[National Academies Press]] | year=2001 | access-date=2007-04-05| doi=10.17226/10139 | isbn=978-0-309-07574-9 }}</ref> has been widely cited. Lindzen subsequently publicly criticized the report summary for not referring to the statement in the full report that twenty years of temperature measurements was "too short a period for estimating long term trends".<ref name="Lindzen">{{cite news | title= Scientists' Report Doesn't Support the Kyoto Treaty | url= http://eaps.mit.edu/faculty/lindzen/OpEds/LindzenWSJ.pdf | last= Lindzen | first= Richard Siegmund | newspaper= [[The Wall Street Journal]] | date= June 11, 2001 | access-date= 2007-04-05 | archive-date= October 17, 2003 | archive-url= https://web.archive.org/web/20031017234851/http://eaps.mit.edu/faculty/lindzen/OpEds/LindzenWSJ.pdf | url-status= dead }}</ref>

===IPCC activities===
Lindzen worked on Chapter 7 of 2001 [[Intergovernmental Panel on Climate Change|IPCC]] Working Group 1, which considers the physical processes that are active in real world climate. He had previously been a contributor to Chapter 4 of the 1995 "[[Intergovernmental Panel on Climate Change|IPCC]] [[IPCC Second Assessment Report|Second Assessment]]". He described the full 2001 IPCC report as "an admirable description of research activities in climate science"<ref name = "canadian_reactions_to_sir_david_king.html">{{cite web | title=Canadian Reactions To Sir David King | url= http://meteo.lcd.lu/globalwarming/Lindzen/canadian_reactions_to_sir_david_king.html | last=Lindzen | first=Richard S. | publisher=[[The Hill Times]] | date=February 23, 2004 | access-date= 2007-04-05}}</ref> although he criticized the [[Summary for Policymakers]]. Lindzen stated in May 2001 that it did not truly summarize the IPCC report<ref>{{cite web | title=Testimony of Richard S. Lindzen before the U.S. Senate Commerce Committee | url = http://www.lavoisier.com.au/articles/climate-policy/science-and-policy/Lindzen_McCain.pdf | last=Lindzen | first=Richard S. | publisher=[[Lavoisier Group]] | date=May 1, 2001 | access-date=March 18, 2009}}</ref> but had been amended to state more definite conclusions.<ref>{{cite news | title=The Deniers – Part V: The original denier: into the cold | url=http://www.canada.com/nationalpost/story.html?id=63ab844f-8c55-4059-9ad8-89de085af353&k=0 | last=Solomon | first=Lawrence | author-link=Lawrence Solomon | newspaper=[[National Post]] | date=December 22, 2006 | access-date=2007-04-05 | url-status=dead | archive-url=https://web.archive.org/web/20070223145833/http://www.canada.com/nationalpost/story.html?id=63ab844f-8c55-4059-9ad8-89de085af353&k=0 | archive-date=February 23, 2007 | df=mdy-all }}</ref> He also emphasized the fact that the summary had not been written by scientists alone. The NAS panel on which Lindzen served says that the summary was the result of dialogue between scientists and policymakers.{{Efn | The NAS panel said on the matter that "The committee finds that the full IPCC Working Group I (WGI) report is an admirable summary of research activities in climate science, and the full report is adequately summarized in the Technical Summary. The full WGI report and its Technical Summary are not specifically directed at policy. The Summary for Policymakers reflects less emphasis on communicating the basis for uncertainty and a stronger emphasis on areas of major concern associated with human-induced climate change. This change in emphasis appears to be the result of a summary process in which scientists work with policy makers on the document. Written responses from U.S. coordinating and lead scientific authors to the committee indicate, however, that (a) no changes were made without the consent of the convening lead authors (this group represents a fraction of the lead and contributing authors) and (b) most changes that did occur lacked significant impact".<ref name=ccs_summary>{{cite web | work =Climate Change Science: An Analysis of Some Key Questions | title = Summary | url = http://www.nap.edu/html/climatechange/summary.html | publisher=[[National Academies Press]] | year=2001 | access-date= 2007-04-05}}</ref>}}

===Work at Cato Institute===
Lindzen was a featured speaker at a [[Cato Institute]] conference, "Global Environmental Crisis: Science or Politics?" on June 5 ([[World Environment Day]]) and June 6, 1991.<ref name=KD>[https://kochdocs.org/2019/08/12/1991-cato-climate-denial-conference-flyer-and-schedule/ "1991 CATO Climate Denial Conference Flyer and Schedule"], "Koch Docs", n.d. Retrieved 2019-08-17.</ref> The conference was identified in 2019 in the book ''[[Kochland]]'' by business writer Christopher Leonard as a previously unhighlighted early landmark in the efforts by the [[fossil fuel]] multi-billionaire [[Koch brothers]] to promote questions about [[climate science]]. Cato Institute was "founded and heavily funded for years" by the Kochs,<ref>[[Jane Mayer|Mayer, Jane]], [https://www.newyorker.com/news/daily-comment/kochland-examines-how-the-koch-brothers-made-their-fortune-and-the-influence-it-bought "'Kochland' Examines the Koch Brothers' Early, Crucial Role in Climate-Change Denial" (review)], ''The New Yorker'', August 13, 2019. Retrieved 2019-08-17.</ref> and Lindzen was prominently quoted in the brochure for the conference.
<blockquote>The notion that global warming is a fact and will be catastrophic is drilled into people to the point where it seems surprising that anyone would question it, and yet, underlying it is very little evidence at all. Nonetheless, there are statements made of such overt unrealism that I feel embarrassed. I feel it discredits science. I think problems will arise when one will need to depend on scientific judgment, and by ruining our credibility now you leave society with a resource of some importance diminished.</blockquote>
The title of the presentation Lindzen made at the conference was "Critical Issues in Climate Forecasting".<ref name=KD/>

In an announcement on December 27, 2013, the Institute said that in a new position at Cato, Lindzen's focus would be on "the interaction between science and policymakers" and that he would study "whether the move from largely private funding to public support has introduced biases into science and the public policies informed by science."<ref name="CATO Dec13" />

By mid-2019, Lindzen was no longer affiliated with the Cato institute.<ref name=":0">{{Cite web|last=Waldman|first=Scott|date=2020-05-29|title=Cato closes its climate shop; Pat Michaels is out|url=https://www.eenews.net/stories/1060419123|access-date=2020-07-28|website=[[Environment & Energy Publishing|E&E News]]|language=en}}</ref>