Climate change denial (also global warming denial) is a form of science denial characterized by rejecting, refusing to acknowledge, disputing, or fighting the extensive evidence for anthropogenic global warming that has led to a scientific consensus on climate change. Those promoting denial commonly use rhetorical tactics to give the appearance of a scientific controversy where none exists. Climate change denial includes raising unreasonable doubts about the extent to which climate change is caused by humans, its effects on nature and human society, and understating the costs of climate change adaptation while overstating the costs of mitigating it. To a lesser extent, climate change denial can also be implicit when people accept the science but fail to reconcile it with their belief or action. Several studies have analyzed these positions as forms of denialism, pseudoscience, or propaganda.

Many issues that are settled in the scientific community, such as human responsibility for climate change, remain the subject of politically or economically motivated attempts to downplay, dismiss or deny them—an ideological phenomenon academics and scientists call climate change denial. Climate scientists, especially in the United States, have reported government and oil-industry pressure to censor or suppress their work and hide scientific data, with directives not to discuss the subject publicly. The fossil fuels lobby has been identified as overtly or covertly supporting efforts to undermine or discredit the scientific consensus on climate change.

Industrial, political and ideological interests organize activity to undermine public trust in climate science. (MSNBC single page version, archived 20 August 2007) Climate change denial has been associated with the fossil fuels lobby, the Koch brothers, industry advocates, ultraconservative think tanks, and ultraconservative alternative media, often in the U.S. See, e.g., pp. 31 ff, describing industry-based advocacy strategies in the context of climate change denial, and p73 ff, describing involvement of free-market think tanks in climate-change denial. More than 90% of papers that are skeptical of climate change originate from right-wing think tanks. Climate change denial is undermining efforts to act on or adapt to climate change, and exerts a powerful influence on the politics of climate change.

In the 1970s, oil companies published research that broadly concurred with the scientific community's view on climate change. Since then, for several decades, oil companies have been organizing a widespread and systematic climate change denial campaign to seed public disinformation, a strategy that has been compared to the tobacco industry's organized denial of the hazards of tobacco smoking. Some of the campaigns are carried out by the same people who previously spread the tobacco industry's denialist propaganda.'Shell knew': oil giant's 1991 film warned of climate change danger , The Guardian

Terminology Climate change denial refers to denial, dismissal, or doubt of the scientific consensus on the rate and extent of climate change, its significance, or its connection to human behavior, in whole or in part. Climate denial is a form of science denial. It can also take pseudoscientific forms.Brown, Michael. Adversaries, zombies and NIPCC climate pseudoscience , Phys.org, 26 September 2013 Deniers often use the term "climate skeptic" or "contrarian" instead, to sow confusion about their intentions.

The terminology is debated: most of those actively rejecting the scientific consensus use the terms skeptic and climate change skepticism, and only a few have expressed preference for being described as deniers. But the word "skepticism" is incorrectly used, as scientific skepticism is an intrinsic part of scientific methodology. In fact, all scientists adhere to scientific skepticism as part of the scientific process that demands continuing questioning. Both options are problematic, but climate change denial has become more widely used than skepticism.Weart, S. (2015) in: The Discovery of Global Warming

The term contrarian is more specific but less frequently used. In academic literature and journalism, the terms climate change denial and climate change deniers have well-established usage as descriptive terms without any pejorative connotation.

The terminology evolved and emerged in the 1990s. By 1995 the word "skeptic" was being used specifically for the minority who publicized views contrary to the scientific consensus. This small group of scientists presented their views in public statements and the media rather than to the scientific community. Journalist Ross Gelbspan said in 1995 that industry had engaged "a small band of skeptics" to confuse public opinion in a "persistent and well-funded campaign of denial". His 1997 book The Heat is On may have been the first to concentrate specifically on the topic. In it, Gelbspan discusses a "pervasive denial of global warming" in a "persistent campaign of denial and suppression" involving "undisclosed funding of these 'greenhouse skeptics'" with "the climate skeptics" confusing the public and influencing decision makers.

In December 2014, an open letter from the Committee for Skeptical Inquiry called on the media to stop using the term skepticism when referring to climate change denial. It contrasted scientific skepticism—which is "foundational to the scientific method"—with denial—"the a priori rejection of ideas without objective consideration"—and the behavior of those involved in political attempts to undermine climate science. It said: "Not all individuals who call themselves climate change skeptics are deniers. But virtually all deniers have falsely branded themselves as skeptics. By perpetrating this misnomer, journalists have granted undeserved credibility to those who reject science and scientific inquiry."

In 2015, The New York Times's public editor said that the Times was increasingly using denier when "someone is challenging established science", but assessing this on an individual basis with no fixed policy, and would not use the term when someone was "kind of wishy-washy on the subject or in the middle". The executive director of the Society of Environmental Journalists said that while there was reasonable skepticism about specific issues, she felt that "denier" was "the most accurate term when someone claims there is no such thing as global warming, or agrees that it exists but denies that it has any cause we could understand or any impact that could be measured".

A petition by climatetruth.org asked signers to "Tell the Associated Press: Establish a rule in the AP Stylebook ruling out the use of 'skeptic' to describe those who deny scientific facts". In September 2015, the Associated Press announced "an addition to AP Stylebook entry on global warming" that advised "to describe those who don't accept climate science or dispute the world is warming from human-made forces, use 'climate change doubters' or 'those who reject mainstream climate science'. Avoid use of 'skeptics' or 'deniers'". In May 2019, The Guardian also rejected use of the term "climate skeptic" in favor of "climate science denier".

In addition to explicit denial, people have also shown implicit denial by accepting the scientific consensus but failing to "translate their acceptance into action". This type of denial is also called soft climate change denial.

Categories and tactics

In 2004, German climate scientist Stefan Rahmstorf described how the media give the misleading impression that climate change is still disputed within the scientific community, attributing this impression to climate change skeptics' PR efforts. He identified different positions that climate skeptics argue, which he used as a taxonomy of climate change skepticism.Rahmstorf, S., 2004, The climate sceptics: Weather Catastrophes and Climate Change—Is There Still Hope For Us? (Munich: PG Verlag) pp. 76–83 [note: numbering not shown in original] Later the model was also applied to denial: Trend skeptics or deniers (who claim that no significant warming is taking place): "Given that the warming is now evident even to laypeople, the trend skeptics are a gradually vanishing breed. They [...] claim that the warming trend measured by weather stations is an artefact due to urbanisation around those stations (urban heat island effect)." Attribution skeptics or deniers (who accept the climate change trends but claim there are natural causes for this, not human-made ones): "A few of them even deny that the rise in the atmospheric carbon dioxide content is anthropogenic; they claim that the atmospheric carbon dioxide is released from the ocean by natural processes." Impact skeptics or deniers (who think climate change is harmless or even beneficial, for example the "potential extension of agriculture into higher latitudes"). Sometimes consensus denial is added, for people who question the existence of the scientific consensus on anthropogenic climate change.

The National Center for Science Education describes climate change denial as disputing differing points in the scientific consensus, a sequential range of arguments from denying the occurrence of climate change, accepting that but denying any significant human contribution, accepting these but denying scientific findings on how this would affect nature and human society, to accepting all these but denying that humans can mitigate or reduce the problems. James L. Powell provides a more extended list, as does climatologist Michael E. Mann in "six stages of denial", a ladder model whereby deniers have over time conceded acceptance of points, while retreating to a position that still rejects the mainstream consensus:

Climate change denial is a form of denialism. Chris and Mark Hoofnagle have defined denialism in this context as the use of rhetorical devices "to give the appearance of legitimate debate where there is none, an approach that has the ultimate goal of rejecting a proposition on which a scientific consensus exists." This process characteristically uses one or more of the following tactics: Allegations that scientific consensus involves conspiring to fake data or suppress the truth: a climate change conspiracy theory. Fake experts, or individuals with views at odds with established knowledge, at the same time marginalizing or denigrating published topic experts. Like the manufactured doubt over smoking and health, a few contrarian scientists oppose the climate consensus, some of them the same people. Selectivity, such as cherry-picking atypical or even obsolete papers, in the same way that the MMR vaccine controversy was based on one paper: examples include discredited ideas of the medieval warm period. Unworkable demands of research, claiming that any uncertainty invalidates the field or exaggerating uncertainty while rejecting probabilities and mathematical models. Logical fallacies.

Discussing specific aspects of climate change science

Some politicians Using example of Republican U.S. Representative Doug LaMalfa. and climate change denial groups say that because is only a trace gas in the atmosphere (0.04%), it cannot cause climate change. But scientists have known for over a century that even this small proportion has a significant warming effect, and doubling the proportion leads to a large temperature increase. Some groups allege that water vapor is a more significant greenhouse gas, and is left out of many climate models. But while water vapor is a greenhouse gas, its very short atmospheric lifetime (about 10 days) compared to that of (hundreds of years) means that is the primary driver of increasing temperatures; water vapor acts as a feedback, not a forcing, mechanism.