H. Leighton Steward

H. Leighton Steward


  • Master of Science (Geology). [1]


H. Leighton Steward is the President and Chairman of Plants Need CO2, a group founded in 2009 with the mission “to educate the public on the positive effects of additional atmospheric CO2 and help prevent the inadvertent negative impact to human, plant and animal life if we reduce CO2.”

Plants Need CO2 was listed as Number four among Mother Jones‘s “Dirty Dozen of Climate Change Denial” in December, 2009. [2]

He is the Chairman of the Institute for the Study of Earth and  Man (ISEM) Board of Trustees, and was Vice Chairman of the American oil and gas company Burlington Resources, Inc. until his retirement in 2000.

According to his profile at EOG Resources (formerly Enron Oil and Gas Company) where he is a director, Steward has extensive experience in the oil and gas exploration and production industry and has also worked with The Louisiana Land and Exploration Company as President, Chief Operating Officer and, Chairman of the Board and Chief Executive Officer from 1989 until its acquisition by Burlington Resources Inc. in 1997. [3]

Stance on Climate Change

“[C]arbon dioxide (CO2) is not a major contributor to current global warming nor to Earth’s paleoclimates.” [4]

Key Quotes

“More CO2 is needed to bolster plant life, which turns the gas into oxygen while also providing food.”

“Temperatures over time have fluctuated while CO2 levels have remained steady. What’s more, temperature increases have historically led increases in CO2 levels.”

“Many, many reputable scientists believe that natural factors overpower the current influence of CO2 on global warming.”

CO2 is a great airborne fertilizer, which, as its concentrations rise, causes additional plant growth and causes plants to need less water.”

“The warning level of CO2 in submarines isn’t reached until the atmosphere has 8,000 parts per million of CO2.” [5]

“Humans have been fertilizing Earth’s greenery worldwide, but not with nitrogen-based fertilizer that runs into the rivers and oceans with very negative effects. We have been raising the level of CO2, which has no negative effect on any plant or animal life.” [21]

Key Deeds

February 23, 2017

H. Leighton Steward 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). [35]

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. [35]

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. [36]

May 2, 2016

H. Leighton Steward was listed among “Key Scientists” appearing in Marc Morano‘s movie, Climate Hustle. The full list included the following: [25] 

Marc Morano’s Climate Hustle was released in U.S. theatres on May 2, 2016. Bill Nye described it as  “not in our national interest and the world’s interest.” [26]

The film was produced by the Committee for Constructive Tomorrow (CFACT) and CDRCommunications. As noted at Desmog’s project, ClimateHustler.org,  CFACT has received funding from ExxonMobil, Chevron, as well as hundreds of thousands of dollars from foundations associated with Richard Mellon ScaifeCFACT has also received at least $7.8 million in “dark money” through DonorsTrust and Donors Capital Fund[27][28]

CDR Communications was behind the 2010 video by the Cornwall Alliance titled Resisting the Green Dragon, which claimed environmentalism was a “false religion” and a “global government” power grab. Chris Rogers of CDR Communictions is also chairman of The James Partnership, the umbrella arm that includes the Cornwall Alliance as one of its projects and pays the salary of Calvin Beisner, Cornwall’s founder and spokesperson. [29]

Climate Hustle initially premiered on December 7, 2015 in Paris, France during the COP21 United Nations summit on climate change[30][31][32]

We are putting together what I think is the most comprehensive, unique, entertaining and humorous climate documentary that has ever been done or attempted,” Morano had said before the film was released. [33]

The reason that this is a unique film,” Morano has said, “is that we are going for a pop culture-friendly… sarcastic approach and we actually give both sides in this movie.”  [33]

In an interview with Ezra Levant, Morano said:

I am not interviewing a lot of the main climate sceptical scientists because I feel like they have been interviewed by many other people and their stories have been told. I am trying to find another layer of scientist whose stories have not been out there yet. You will see a lot of new names in this.” [33]

See a preview of the film below:

At the Paris premier of the film, reporters from Desmog and the Irish Times were denied entrance after having their RSVPs accepted days earlier. [34]

December 7, 2015

Leighton Steward appears as a “Key Scientist” in Marc Morano’s documentary film, Climate Hustle, which debuted on December 7, 2015, in Paris, France during the COP21 United Nations summit on climate change. [23] The film chiefly showcases Morano’s personality, a range of discredited scientists, and no new factual information about climate change.

Other notable “Key Scientists” featured in Climate Hustle include: [23]

November 19, 2015

H. Leighton Steward was a speaker at an event hosted by the Texas Public Policy Foundation titled “At the Crossroads Energy & Climate Policy Summit.” [24]

Leighton Steward spoke as part of Session 1, “The Earth’s Climate History” alongside Don Easterbrook. According to the event description, “This panel will discuss the earth’s 1500-year climate cycles which, at times, have had higher temperatures and CO2 levels than today.” [24]

The full list of event speakers was as follows: [24]

Robert E. MurrayFounder, Chairman, President, and CEO of Murray Energy Corporation, the nation’s largest underground coal mining commpany.
H. Leighton StewardMember, TheRightClimateStuff.com
Dr. Don EasterbrookProfessor Emeritus of Geology at Western Washington University
Dr. Will HapperCyrus Fogg Brackett Professor of Physics, Emeritus, Princeton University
Dr. Richard LindzenAlfred P. Sloan Professor of Meteorology, Department of Earth, Atmospheric and Planetary Sciences, MIT
Dr. Patrick MooreAuthor and founding member of Greenpeace
Dr. E. Calvin BeisnerSpokesman for the Cornwall Alliance for the Stewardship of Creation
Horace CooperAdjunct Fellow, National Center for Public Policy Research
Dr. Caleb RossiterAdjunct Professor, School of International Service and Adjunct Professor, Department of Mathematics and Statistics, College of Arts and Sciences at American University
Mark P. MillsSenior Fellow, Manhattan Institute and founder andCEO, Digital Power Group
Dr. Hal DoironFormer NASA Engineer and Chairman, The Right Climate Stuff Research Team
Walter CunninghamFighter Pilot, Col. USMCR-Ret.; Physicist; Apollo 7 Astronaut
Dr. George L. StegemeierPresident, GLS Engineering, Inc.
Stephen MooreDistinguished Visiting Fellow on the Project for Economic Growth at the Heritage Foundation
Robert L. Bradley Jr.CEO, Institute for Energy Research
Mike NasPartner, Environmental and Legislative Affairs Practice Group, Jackson Walker L.L.P.
Marc MoranoFounder, ClimateDepot.com
Ray GiffordPartner, Wilkinson Barker Knauer LLP
Brian LloydExecutive Director, Public Utility Commission of Texas
John CornynU.S. Senator and Senate Majority Whip John Cornyn

June 11–12, 2015

Steward was a moderator at the Heartland Institute‘s Tenth International Conference on Climate Change (ICCC10) in Washington, D.C. [37]

He moderated Panel 13: “The Right Climate Stuff” with Walter Cunningham, Hal Doiron, and Thomas Wysmuller.

January 12, 2015

H. Leighton Steward was a guest on the Heartland Institute’s daily podcast where he describes his role in The Right Climate Stuff (TRCS) and his group’s conclusion that “there is no convincing physical evidence of catastrophic man-caused global warming.” 

According to Leighton, the report concludes that “Real, empirical evidence does not support global warming.” The Right Climate Stuff website does not provide a list of all contributing authors or their credentials, however the list of 20 “Appolo era NASA retirees” includes noted climate change skeptics Harold Doiron and Walter Cunningham [20]

TRCS’s report is addressed at SkepticalScience, where many of the questions posed in the report are provided answers. [16]

September 26, 2014

H. Leighton Steward attends the “At the Crossroads; Energy & Climate Policy Summit in Houston, Texas, hosted by the Texas Public Policy Foundation and The Heritage Foundation. Steward presents in “Panel V: Prosperity and Poverty,” with Calvin Beisner. [14]

July 7 – 9, 2014

Steward was a moderator at the Heartland Institute’s Ninth International Conference on Climate Change (ICCC9) in Las Vegas, Nevada. [13] He moderated Panel 6: “The Right Stuff” with Thomas Wysmuller, Hal Doiron, and Walter Cunningham

DeSmogBlog has done in-depth research on the other speakers and sponsors from Heartland’s ICCC9, which can be found here.

January 2013

H. Leighton Steward was on a Panel at the National Press Club titled “Climate Change – Science or Hype.” Panelists also included Harold Doiron, Scott Sklar of The Stella Group, Daniel Wiess of the Center for American Progress, Monical Dorhoi of World Bank, Keven Book of CleanView Energy Partners and David Kruetzer of the Heritage Foundation. [15

At thist time, Steward also headed a group called “The Right Climate Stuff,” largely made up of of a group of NASA retirees. [16], [17], [18]

Doiron is also listed as “lead author” for TRCS‘s February 2014 Report (PDF). [19]

The Right Climate Stuff released a report and press release where they summarize their findings as follows:

  1.  The science that predicts the extent of anthropogenic global warming is not settled science.
  2. There is no convincing physical evidence of catastrophic anthropogenic global warming.
  3. Computer models need to be validated before being used in critical decision-making.
  4. Because there is no immediate threat of global warming requiring swift corrective action, we have time to study global climate changes and improve our prediction accuracy.
  5. The U.S. government is over-reacting to concerns about anthropogenic global warming.
  6. A wider range of solution options should be studied for global warming or cooling threats from any credible cause.

The group also presented at the Heartland Institute’s 7th International Conference on Climate Change (ICCC-7) in 2012 in Chicago. 

May 21–23, 2012

Steward was a speaker at the Heartland Institute’s Seventh International Conference on Climate Change (ICCC7). He spoke on the NASA letter writer’s panel with Walter Cunningham, Thomas Wysmuller, Harold Doiron, and Harrison Schmitt. Footage can be viewed below. 

DeSmogBlog researched the co-sponsors behind Heartland’s ICCC7 and found that they had collectively received over $67 million from ExxonMobil, the Koch Brothers and the conservative Scaife family foundations.

July 14, 2010

CO2 is Green, the sister organization of Steward’s “Plants Need CO2released an ad campaign fighting the president’s cap-and-trade bill.

The ad, featured in The Washington Post, urges people to vote against “the president’s cap-and-trade bill that will increase your cost of living and not change the climate.”

According to the ad, “The bill is based on the false premise that man-made CO2 is a major cause of climate change. Real, empirical evidence indicates it is not.” [6]

Steward is the spokesman and Chairman for CO2 is Green, as well as the President and Chair of Plants Need CO2.

May 16–18, 2010

Steward was a keynote speaker at the Heartland Institute’s Fourth International Conference on Climate Change (ICCC4). [7] HIs speech, titled “Empirical Evidence (Paleoclimates) and the Disconnect of Climate Change” can be viewed below. 

DeSmog has done research on the co-sponsors of the conference and found that 19 of the 65 sponsors (including Heartland itself) have received a total of over $40 million in funding since 1985 from ExxonMobilKoch Industries family foundations or the Scaife family foundations.


Published “Fire, Ice and Paradise” which he describes as “an educational book for the non-scientist, including politicians, regarding the many factors affecting global climate change.”

“The bottom-line summary of the author’s opinion after research of the scientific literature is that carbon dioxide (CO2) is not a major contributor to current global warming nor to Earth’s paleoclimates.”

According to Leighton Steward, “In addition to being shown to not being a significant driver of current temperature change, CO2 is shown to be a positive factor in Earth’s ecosystems, a benefit to the plant (food) kingdom and thus the animal kingdom, which includes humanity.” [4]



According to a search of Google Scholar, Steward has not published any articles in peer-reviewed journals on any subject.



  1. REGISTER ENDORSERS FROM THE UNITED STATES OF AMERICA of The Climate Scientists’ Register,” International Climate Science Coalition. Accessed May, 2012.
  2. Josh Harkinson. “No. 4: Plants Need C02,” Mother Jones (Part of “The Dirty Dozen of Climate Change Denial series), December 4, 2009.
  3. Officers/Board,” eog resources. Accessed May 7, 2012.
  4. “Recommended Reading List: ‘Fire, Ice and Paradise’, Steward, H.L. (2009),” Planes Need CO2. Accessed May , 2012. Archived May 7, 2012 with WebCite.
  5. Paul Bedard. “Steward’s 10 ‘Myths’ About Global Warming and CO2 Damage,” Washington Whispers, October 9, 2009.
  6. Anne C. Mulkern. “Ads Backed by Fossil-Fuel Interests Argue ‘CO2 Is Green’,” The New York Times, July 14, 2010.
  7. Speakers,” 4th International Conference on Climate Change, May 9 , 2010. Archived June 10, 2011.
  8. 2009 Form 990 for Plants Need CO2.org (PDF). Retrieved from foundationcenter.org.
  9. Institute Trustees,” Institute for the Study of Earth and Man. Accessed May 7, 2012.
  10. Daniel F. Cuff. “BUSINESS PEOPLE,” The New York Times, November 17, 1988.
  11. H. Leighton Steward,” SourceWatch.
  12. ExxonSecrets Factsheet: H. Leighton Steward.
  13. Return of Climate Denial-a-Palooza: Heartland Institute Hitches Anti-Science Wagon to Vegas FreedomFest,” DeSmogBlog, July 7, 2014. Archived July 14, 2014.
  14. H. Leighton Steward. “Speakers,” At the Crossroads; Energy & Climate Policy Summit, Texas Public Policy Foundation, The Heritage Foundation, September 25/26, 2014.
  15. “’The Hard Question™’ Launches at National Press Club, The Conversation begins with ‘Setting the Course on Energy’” (Press Release), Pr News Wire. January 21, 2013.
  16. NASA Retirees Appeal to their Own Lack of Climate Authority,” SkepticalScience. January 24, 2013. 
  17. CO2isGreen.org: Team of Ex-NASA Scientists Concludes No Imminent Threat from Man-Made CO2” (Press Release), Pr Newswire. January 23, 2013. 
  18. The Right Climate Stuff Team Releases New Report, Finds ‘No Convincing Evidence Indicating Our Planet Is in a Climate Crisis’,” The Heartland Institute. April 13, 2013.
  19. Harold H. Doiron. “Bounding GHG Climate Sensitivity for Use in Regulatory Decisions,” February 2014. Retrieved from therightclimatestuff.com June 1, 2015.
  20. H. Sterling Burnett. “Heartland Daily Podcast – H. Leighton Steward,” Somewhat Reasonable. January 12, 2015.
  21. H. Leighton Steward. “Senators Should Know the Truth about Global Warming Leighton Steward,” TownHall.com. March 26, 2014.
  22. About,” Co2Coalition. Archived September 4, 2015. 
  23. Background on Key Scientists Appearing in Climate Hustle,” Climate Hustle. Archived January 11, 2016.
  24. At The CrossRoads Energy & Climate Policy Summit,” Crossroads-Summit.com. Archived July 4, 2016. Archived .pdf on file at DesmogBlog
  25. “Background on Key Scientists Appearing in Climate Hustle” (PDF), ClimateHustle.org. Archived .pdf on file at Desmog.
  26. ‘Climate Hustle’ debuts as skeptics take on global-warming ‘consensus’,” The Washington Times, May 1, 2016. Archived August 26, 2016. Archive.is URL: https://archive.is/XtLXp
  27. Background on Climate Hustle Host and Producers,” ClimateHustle.org. Archived .pdf on file at Desmog.
  28. Homepage, climatehustler.org. Archive.is URLhttps://archive.is/NB9qn
  29. Graham Readfearn. “The Evangelical Christian Climate Deniers Behind Marc Morano’s Climate Hustle Documentary,” Desmog, November 19, 2015.
  30. Matthew Kasper, “Climate Hustle, Latest Global Warming Denial Documentary, Set For World Premiere In Paris During COP21,” Republic Report, November 13, 2015. Archive.is URLhttps://archive.is/s7OHs
  31. Climate Hustle,” SourceWatch, accessed November 14, 2015. Archive.is URLhttps://archive.is/bOG35
  32. Background on Key Scientists Appearing in Climate Hustle,” Climate Hustle. Archived January 11, 2016.
  33. Graham Readfearn. “Marc Morano’s Climate Hustle Film Set For Paris Premiere With Same Old Denial Myths,” Desmog, November 12, 2015.
  34. Graham Readfearn. “The Fakery of the Paris ‘Red Carpet’ Premiere of Marc Morano’s Climate Hustle Film,” Desmog, December 30, 2015.
  35. “PETITION” (PDF), February 23, 2017. Richard Lindzen. PDF Archived at DeSmog.
  36. 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.
  37. “Tenth International Conference on Climate Change, Program,” (PDF) Heartland Institute. Archived February 13, 2018. 

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