Weather Denial Documents

Below is an annotated collection of documents gathered through the years amassing evidence of corporate efforts to deny the connection between climate change and extreme weather events.  

There are two major blocks of evidence:

They knew climate change would cause extreme weather: Corporate entities “knew” extreme weather would be an impact of anthropogenic climate change. And they knew it would be hard for scientists to do what they can do now, attribute the exact impact of climate change on specific weather events.

They denied the connection: They blocked public understanding of the connection between climate change and extreme weather, using PR campaigns, third party surrogates and other means. They sought to shut down voices who discussed climate change in the context of extreme events.

Current state of extreme weather attribution science: At the end, we include a section on the best available modern science linking extreme weather events to climate change.


Documents dating back many decades show that the fossil fuel industry and allies knew that human-induced climate change would raise global temperatures and alter the frequency and intensity of extreme weather events, including hurricanes, heavy rain events, floods, droughts and heatwaves. The collection below confirms efforts by those same industries to cloud the science and the discussion of weather and climate, efforts that continue to this day. They engaged in efforts to stop public officials, scientists, advocates and the media from reporting on extreme weather events as connected to climate change.  

By the late 1980s, mainstream media outlets were increasingly linking extreme weather events to human-induced climate change, such as the dust bowl-like “long hot summer of ’88” that triggered the Senate hearings in which Dr James Hansen declared climate change a present danger.   Fossil fuel companies, their trade associations and coalitions – such as the American Petroleum Institute and the Global Climate Coalition – published reports, press releases and held public events discounting the climate science consensus and downplaying the threat of extreme weather and more importantly the connection between extreme weather and climate change.  Industry-funded third party surrogates like Accu-Weather, front groups like the Cooler Heads Coalition, and academics including hurricane expert Dr. William Gray at Colorado State University (now deceased) were deployed to downplay the connection between climate science and extreme weather.

The other common tactic employed by climate deniers is to mock out-of-season weather such as when Senator James Inhofe held up a snowball on the Senate floor. It is common to see parties interested in ridiculing the climate crisis scoffing on cold days in warm seasons (“so much for global warming!”) or playing up unseasonably warm days in winter as if that is a good thing. We are not covering these communications efforts in this dossier.


Here are the documents featured in this post:



We will start with the more recent denial phase, followed by documents showing that that “they knew” or should have known about the connections between climate change and weather disruption .

Extreme Weather Denial

As soon as climate change became an active public policy issue, really after the hot summer of 1988, the James Hansen Senate hearing, corporate forces in the United States began to express concern internally and spread doubt externally about connecting climate change to weather events. Below are documents from 1989 to 2006, showing the many facets of efforts to stop the discussion of extreme weather as a consequence of climate change.

February 1989 Exxon internal document – “Potential Enhanced Greenhouse Effects: Status and Outlook”
A February 22, 1989 presentation by Duane LeVine of Exxon expresses concern about the way the 1988 extreme heat and drought had escalated the public policy discussion, precisely because it was an example of things to come:

* Potential Enhanced Greenhouse was the term for anthropogenic climate change used in this Exxon document.

May June 1991 – ICE Campaign “Information Council on the Environment”
This short-lived campaign, funded by coal and electric utility corporate interests, mocked attention to climate change and weather with ads aimed at audiences in Minnesota, North Dakota, Arizona, Ohio and Kentucky. Some examples of the ads are below:

1995 Global Climate Coalition handout – “Climate Change: Your Passport to the Facts”
In 1995, the GCC’s “Climate Change: Your Passport to the Facts,” a pamphlet made to look like a passport, was distributed at the UN climate convention that year. Denying both the consensus and threat of anthropogenic climate change and the connection between climate change and extreme weather, the pamphlet states: “Fact: Science does not support claims that recent floods, hurricanes and other extreme weather events are the fingerprint of human-induced climate change.” To support this claim, the GCC cites a 1995 report produced by Accu-Weather, which was commissioned and paid for by the GCC and its member companies (see below).


GCC Commissions Accu-Weather Report

February 1995 Accu-Weather GCC Report – “Changing Weather? Facts and Fallacies about Climate Change” 
In 1994, the GCC hired Accu-Weather Inc., a reputable weather forecasting service that served television and radio, to produce a report rejecting the connection between climate change and extreme weather events including: heavy storms, hurricanes, flooding, drought, heat waves, winter storms and tornadoes. The report placed blame for perception of increased extreme weather on more people living in harm’s way and increased news coverage of weather events, an argument you still hear today.

The report states: “No convincing, observational evidence exists that hurricanes, tornadoes and other extreme temperature and precipitation events are on the rise because of the recent slight increase in the Earth’s surface temperature. Rather, the greater attention severe weather events now receive may simply reflect two non-weather related facts: a) More people live in areas that were once sparsely populated or even uninhabited, and b) local media are now able to quickly report extreme weather … in distant parts of the globe.”

February 1995 GCC News Release – “Leading Forecasting Group Finds No Rise in Extreme Weather”

GCC Promotional material about their Accu-Weather report

March/April 1995 GCC Climate Watch Bulletin Vol. 3 Issue 2
This March/April 1995 newsletter mailed to journalists and other audiences included a front page article amplifying the Accu-Weather report.

July/August 1995 GCC Climate Watch Bulletin Vol. 3 Issue 4
This July/August 1995 issue had a front page article on the World Meteorological Organization report on climate change “WMO Report on Climate Change in 1994 Confirms No Increase in Weather Anomalies” an example of the ongoing effort to decouple discussion of extreme weather from climate change.

July 1995 GCC Communications Program report and budget, prepared for GCC Board 
Here the GCC Communications Committee takes credit for preparing and launching the Accu-Weather report.

January/February 1996 – Global Climate Coalition Science and Technology Committee (STAC), Meeting Materials
These meeting minutes include several news clippings distributed to attendees that discussed the January 1996 blizzard and possible ties to climate change:
> Washington Post, Jessica Mathews, “Is Global Warming the Problem?”
> The New York Times, William K. Stevens, “Blame Global Warming for the Blizzard”
> Newsweek, Sharon Begley, “He’s Not Full of Hot Air”

July 1997 – GCC White House Meeting and STAC Conference Call
These internal meeting notes from a July 24, 1997 meeting of the GCC STAC show that the GCC was actively commissioning research denying the connection between climate change and extreme weather events.

Item two of the meeting summary states: “Bob Gehri [Southern Company] contacted Bob Davis [Robert E. Davis], a University of Virginia climatologist, about writing a paper for GCC use on climate change and extreme weather events. Davis has expressed interest and will provide a proposal to STAC in the next week or so.”
The Davis paper was eventually published in a book by the Frasier Institute, a group that would be funded by ExxonMobil in the early 2000s with climate specific grants.

October 1997 -Vice President Al Gore invited the nations most popular TV weather casters to the White House President Clinton spoke to the attendees that included the most popular weather personalities in large media markets and included NBC’s Al Roker. Gore’s effort was to urge the nation’s TV weather casters to talk about climate change on air. After the event, there was backlash from some hardened climate deniers among those in attendance and by others saying the issue was too political to talk about during the TV weather forecast. Full tape below, Clinton’s call to arms starts here.

At the end of his speech Clinton says, “but we can’t do it until we build the awareness of the American people so I hope you will think about how your work has been affected by what we believe is going on in the climate and again, I don’t ask for you to advocate or do anything outside whatever your own convictions or parameters of permissible speech are but I do think it’s very important since you have more influence than anybody does on how the American people think about this that at least you know what you believe and how you think we should proceed. Thank you for being here and thank you for your leadership.

Those responding negatively to this White House effort included Dr. Neil Frank, a meteorologist who was once director of the National Hurricane Center (NHC) in Florida. Dr. Frank continues to deny climate change is influencing hurricanes in recent years..

1998-99 GCC UNFCCC handout. This folder was handed out at the UN climate negotiations by Frank Maisano, who did communications work for the Global Climate Coalition. It included a two-sided sheet titled “SEVERE WEATHER”, the starkest climate science denial among the GCC’s many complaints about the evolving climate negotiations. The Severe Weather sheet has selected quotes from IPCC reports and NOAA, but mostly consists of quotes from climate deniers, John Christy and Patrick Michaels. Christy’s satellite vs ground temperature thesis would later be discredited by a Bush Administration climate science panel.

(We have a complete original copy of this folder in our archives.)

February 1998 API Climate Change Strategy proposal
This February 27, 1998 document includes an explicit plan to:

“Develop and implement a campaign-style “rapid response” team…to respond to op-eds that make exaggerated claims about climate science…and to media events staged by government officials and/or environmental organizations seeking to tie extreme weather events to possible human impacts on global climate.”

Cooler Heads Coalition efforts to blunt attention to extreme weather

The Cooler Heads Coalition was composed of non-profit organizations who opposed climate policy and denied climate science. The coalition was launched with a grant from Exxon in 1997.

October 9, 1998 – Cooler Heads Coalition “Extreme Weather and Global Climate Change” Congressional and Media Briefing on Capitol Hill
This briefing invitation has a long list of Sponsoring Organizations with leading anti-government and anti-regulatory non-profit organizations who would serve as climate denial surrogates for Exxon, ExxonMobil and Koch interests in years to follow.

January 1998 blog – Changing Weather? Facts and Fallacies about Climate Change and Weather Extremes

May 1997 Robert Balling report: “Calmer Weather – The Spin on Greenhouse Hurricanes” released on, the Cooler Heads Coalition website.

January 1999 Cooler Heads Coalition article decrying a Ross Gelbspan letter to the New York Times

April 1999 GCC Backgrounder – “Insurance study on global warming impact”
Frank Maisano of the GCC sent a memo touting a Reuters article about an American Insurance Association study claiming there was no additional risk posed by the climate impact on hurricanes and that global warming might in fact lessen damage from winter events, a rosy narrative on the positive effects of climate change. Meanwhile globally, the reinsurance industry had already begun to sound the alarm about rising costs of climate disasters.

September 1999 – GCC Memo Re: Hurricanes
On September 16, 1999, Frank Maisano of the GCC faxed a short memo to “Communicators Interested in Global Climate Issues” (meaning possibly reporters and communications officers at companies and NGOs) questioning the fact that climate change has an impact on hurricanes. This memo was sent as Hurricane Floyd was leaving a trail of flooding and wind damage making landfall in the Outer Banks of North Carolina and sliding up the East coast.

1999 Greening Earth Society publishes “State of the Climate Report”
This 1999 report edited by Patrick Michaels, paid for by the Greening Earth Society and funded by coal mining interests (the Western Fuels Association) included essays titled “Going to Extremes: Coverage of 1998’s Not-So-Unusual Weather” and “Why Higher Temperatures Are Better for People.”

The coal mining industry funded Greening Earth Society began to spread a bizarre counter-narrative about climate change in a 1992 film released on VHS tape The Greening of Planet Earth, followed by the 1998 sequel “The Greening of Planet Earth Continues”. This campaign used images of Adam and Eve in the Garden of Eden, and claimed that carbon dioxide pollution and climate change would make the planet more hospitable, not less. This effort continues to this day with the CO2 Coalition (See August 2023 post Is Weather Really Getting More Extreme?”).

January 2004 ExxonMobil New York Times advertorial – “Weather and Climate”
The ad continues efforts to interrupt the discussion of weather and climate , claiming “weather and climate are not the same – climate is far more complex” and continues with straight up climate denial, “scientific uncertainties continue to limit our ability to make objective, quantitative determinations regarding the human role in recent climate change or the degree and consequences of future change.”

September 2004 – TechCentralStation Roy Spencer blog titled Charley, Frances, Ivan and Global Warming
TCS was another DCI Group communications project. Here they published an article by Roy Spencer that concludes:
“When a rash of hurricanes occurs, or a gaggle of tornadoes, people like to search for reasons. It helps make being at the mercy of Mother Nature a little less scary. But we forget that unusual weather is, well, usual. I’m afraid science can’t yet offer a much better explanation than that.”

June 2006 – Video News Release to TV stations by DCI Group denying hurricanes affected by climate change
In the spring of 2006, less than a year after Hurricane Katrina, the DCI Group – a Washington DC based lobby and campaign contractor – produced and distributed VHS cassettes with a fabricated news broadcast and sent the tape to Gulf of Mexico area news stations.

They Knew
There is an abundance of evidence that corporate forces knew that anthropogenic climate change or global warming was occuring in the 1960s and earlier. The feared impacts primarily discussed in these early documents and studies including sea-level rise and warming at the poles and of the ice sheets. But it was understood that large scale climate shifts would of course cause different weather patterns, and links to extreme weather were discussed intermittently in scientific literature.

The 1960s
The evidence that the coal industry along with the oil majors and API knew and were talking about climate change in the 1960s. In 1965, Frank Ikard, head of American Petroleum Institute gives a speech at the API meeting acknowledging the landmark November 1965 Science Advisory Committee Report to President Johnson with a chapter on Atmospheric Carbon Dioxide.

Media coverage of that report included this story in the Miami Herald with direct reference to CO2 pollution and its future impact on weather.

There was a lot of discussion of the topic in this time period. In 1965, the National Science Foundation explored the topic directly, and a month or so later the National Academy of Sciences published a report:

December 1965 Weather and Climate Modification, Report of the Special Commission on Weather and Climate Modification, National Science Foundation (HT Brad Johnson)

January 1966 Weather and Climate Modification: Problems and Prospects, Final Report of the Panel on Weather and Climate Modification to the Committee on Atmospheric Sciences, National Academy of Sciences

“Although dire predictions of drastic climate changes resulting from the increasing carbon dioxide content of the atmosphere as a result of human activities may well be unjustified, it is clearly important that the secular changes of carbon dioxide be followed with great care.

Hat tip to Brad Johnson who flags these words of doubt and caution as an early signal of climate denial in a remarkable climate change timeline post on Medium: A Timeline of Climate Science and Policy. There are numerous mentions of feared changes in weather patterns through the 1960s and 70s.

October 1979 – Exxon Memo on Potential Impact of Fossil Fuel Combustion 

This 1979 Exxon internal document refers to extreme weather impacts including drought, storms, hurricanes and impacts on snowpack. The memo, which was distributed to Exxon managers, author Steve Knisley accurately predicted atmospheric carbon dioxide concentrations in the 2010s. In Appendix A of the report, Knisley also quotes directly from Eugene K. Peterson’s 1969 article “Carbon Dioxide Affects Global Ecology,” describing the ecological consequences of increased atmospheric CO2, including:

  • acute water shortages in the southwestern United States;
  • reduced winter snowpack in the Cascades, Sierras, and Rockies;
  • violent storms;
  • major shifts in weather patterns;
  • other predicted ecological impacts.

November 1982 – Exxon Memo Summarizing Climate Modeling and CO2 Greenhouse Effect Research

On November 12, 1982, Marvin B. Glaser, manager of the Environmental Affairs Program at Exxon, sent a memo to Exxon management containing “CO2 Greenhouse Effect: A Technical Review,” an April 1982 report prepared by the Exxon Research and Engineering Company Coordination and Planning Division on the greenhouse effect. Despite recognizing that “considerable uncertainty also surrounds the possible impact on society of such a warming trend, should it occur,” the report projects that a number of ecological and weather-related changes could occur as a result of increasing atmospheric CO2, including some “potentially catastrophic events” such as “flooding on much of the U.S. East Coast, including the State of Florida and Washington, D.C” if the Antarctic Ice Sheet were to melt (20).

1988 Shell confidential report “The Greenhouse Effect” with 1985 Appendix 8, “Visit to the Climate Research Unit”
This document is an internal report marked “Confidential.” It summarizes a five year internal study of climate change done by Shell between 1981 and 1986. The study contains an acknowledgement of the increase in the frequency of tropical storms.

“The most difficult effect of a global warming to predict is that on rainfall. Dynamic climatology is, after all, a very new science! In high latitudes (60-70 degrees, for example), rainfall ought to increase just because of the raised temperature; we may, after all, be doubling the water vapour content. Monsoon rainfall ought to increase also as should the frequency of tropical storms which is again a temperature dependent phenomenon. It is much more difficult to say anything about the mid-latitude drying forecast by some modeling and even more so to make sensible comments on possible changes in equatorial regions.”

1989 Oct Confidential Shell Group Planning Scenarios 1989-2010 Challenge and response This document published recently by Vatan Hüzeir of Changerism, was part of his study: “Dirty pearls: exposing Shell’s hidden legacy of climate change accountability, 1970-1990”. The excerpts of these planning scenarios that are available, include a statement on predictable climate change impacts: “there would be more violent weather – more storms, more droughts, more deluges.”

1991 Shell film production – “Climate of Concern
@9:30 “If the weather machine were to be wound up to such new levels of energy, no country would remain unaffected”
@10:40 “What is now considered abnormal weather could become a new norm”
The film dwells on the impact on poorer countries and included interesting statements in the narration including, “Who would take care of such ‘greenhouse refuges’?” and “Global warming is not yet certain, but many think the wait for final proof would be irresponsible.”

1991 BP film – “This Earth – What Makes Weather?”
In 1991, BP released a film called “This Earth – What Makes Weather?” which briefly discussed the ways that climate change might impact extreme weather events, including increasing the severity and frequency of storms, flooding, and drought.

  • Storms – “From warmer seas, more water would evaporate. Making storms and the havoc they cause more frequent.” (20:02)
  • Flooding – “In 1953, the North Sea broached the ducts of Holland. Such catastrophic floods could become commonplace and low-lying countries like Bangladesh would be defenseless against them.” (20:16)
  • Drought – “Away from the coasts, we could see a return to the conditions which devastated America’s Midwest in the 1930s. Global warming could repeat on a more disastrous scale the Dust Bowl phenomenon, which virtually destroyed farming on the great plains.” (20:40)
  • Drought – “Are the persistent droughts that have ravaged the heart of Africa the first stark sign of global warming? Some would say so. That opinion is speculative. But the threat of such climatic change is now one of our most urgent concerns. Never has it been more important to understand climate and the seemingly chaotic mechanisms of weather.” (21:27)

1998 Shell Oil “There Is No Alternative” scenario planning  
This document shows that Shell not only knew people would connect the dots between extreme weather events and climate change, but that they would eventually be blamed. This 1998 scenario planning exercise included a prescient prediction: “In 2010, a series of violent storms causes extensive damage to the eastern coast of the US. Although it is not clear whether the storms are caused by climate change, people are not willing to take further chances.”

If you know of more such evidence, please get in touch:


Despite years of corporate efforts to deny the relationship between extreme weather events and climate change, scientists have confirmed that which was predicted long ago.

Extreme weather events can often, but not always, be attributed to climate change. World Weather Attribution, an organization that conducts rapid attribution studies, is a leader in this field. Notably, they have shown that some heatwaves, like the 2021 Pacific Northwest heat dome , extreme rainfall events (like those that triggered the flooding in Midleton, Ireland in 2023, wildfires like those in Canada in 2023, and damaging storms like Hurricane Harvey in 2017, and more have been made worse and/or more likely from climate change.  

Climate litigation has been filed against Big Oil for the Pacific Northwest heat dome, as many researchers have found that event would have been virtually impossible without human-induced climate change. Using tree ring data, a separate group of researchers also found that the Pacific Northwest heat dome was unprecedented during the last millennium. The historical record shows heatwaves like this did not occur in the past, but climate change is making them extremely likely to occur in the future. Other researchers attribute the increased risk of heat domes to background warming, enhanced soil moisture-atmosphere interactions, and increased heat dome-like circulation, all symptoms of climate change. 

Another example of a climate-fueled extreme weather event is Hurricane Harvey, which hit the Texas Panhandle in August and September of 2017, leaving a disaster in its wake. The impacts of hurricanes are exacerbated by climate change in the following ways: (1) the increase in water vapor in the atmosphere due to climate change creates conditions that lead to increased precipitation during a hurricane, (2) sea level rise from climate change allows storm surges to propagate further inland causing more coastal flooding, (3) the drastic increase in heat in the oceans – as compared to the atmosphere – causes stronger hurricanes, (4) the increase in ocean temperature creates a longer hurricane season, (5) an increase in warm pools (especially in the Gulf of Mexico) can rapidly intensify hurricanes just before they hit land, and (6) the movement of hurricanes is getting slower, allowing them to stall over land further intensifying precipitation impacts; the slowing of hurricanes is directly proportional to an increase in sea surface temperature. Specifically, climate change caused as much as 40% more precipitation during Hurricane Harvey, but the economic damages increased by almost 200%. In other words, the economic damage from Harvey increased exponentially compared to the increases in precipitation from climate change, a trend observed in the 2017 Atlantic storm season that helped set the record for weather-related losses in the U.S. and that poses potentially huge costs to communities. 


  1.  “World Weather Attribution,” World Weather Attribution, 2024,
  2.  Sjoukje Y. Philip et al., “Rapid Attribution Analysis of the Extraordinary Heat Wave on the Pacific Coast of the US and Canada in June 2021,” Earth System Dynamics 13, no. 4 (December 8, 2022): 1689–1713,
  3.  Karen J. Heeter et al., “Unprecedented 21st Century Heat across the Pacific Northwest of North America,” Npj Climate and Atmospheric Science 6, no. 1 (February 17, 2023): 21,
  4. Xing Zhang et al., “Increased Impact of Heat Domes on 2021-like Heat Extremes in North America under Global Warming,” Nature Communications 14, no. 1 (March 27, 2023): 1690,
  5. Maofeng Liu et al., “Projection of Landfalling–Tropical Cyclone Rainfall in the Eastern United States under Anthropogenic Warming,” Journal of Climate 31, no. 18 (September 15, 2018): 7269–86,
  6. James P. Kossin et al., “Global Increase in Major Tropical Cyclone Exceedance Probability over the Past Four Decades,” Proceedings of the National Academy of Sciences 117, no. 22 (June 2, 2020): 11975–80,
  7.  Katharine Hayhoe et al., “Our Changing Climate. In Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, Volume II” (U.S. Global Change Research Program, Washington, DC, USA, 2018),
  8.  Lin Li and Pinaki Chakraborty, “Slower Decay of Landfalling Hurricanes in a Warming World,” Nature 587, no. 7833 (November 2020): 230–34,
  9. Mark D. Risser and Michael F. Wehner, “Attributable Human-Induced Changes in the Likelihood and Magnitude of the Observed Extreme Precipitation during Hurricane Harvey,” Geophysical Research Letters 44, no. 24 (2017)
  10.  David J. Frame et al., “The Economic Costs of Hurricane Harvey Attributable to Climate Change,” Climatic Change 160, no. 2 (May 1, 2020): 271–81,

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