Why do so many Americans deny climate change?

August 21, 2014, by Michael Gillenwater

Are you puzzled by American attitudes on climate change? Within the international climate change community, U.S. policy has been met with a mix of hope and frustration. Following the release of the U.S. national assessment report on the heels of the IPCC fifth assessment, the characterization of climate change appears to be shifting in American public discourse. What was previously “a series of impacts that will only be felt in the distant future,” is increasingly described as something that is already happening. Even politicians that in the past eagerly denied global warming, have begun to moderate their challenges of climate science, with some now avoiding comment altogether on grounds they are “not qualified to talk about it.”

This subtle shift in American discourse on climate change has also coincided with some domestic action, most prominently in President Obama’s recently proposed new greenhouse gas (GHG) emission reduction policies. Together, these developments have prompted a hopeful question:

Are we seeing Americans finally embrace climate change science and exhibit concern about climate change impacts?

A Ticking Clock: Made in America

As time marches, the window for climate action further narrows putting an ever greater onus on near term success of international cooperation to reduce global GHG accumulations. A number of barriers stand in the way of an effective multilateral solution, barriers that American leadership holds the unique potential to obviate.

However, that leadership will require a strong majority of Americans to not just believe in climate change, but take serious the threat it poses and prioritize it as a top concern for government action. While it is naïve to think that immediate and effective climate action will ensue from a small change in American beliefs, public opinion does affect U.S. policy on issues Americans deem important. If you are reading this blog post you are probably working on climate change in some capacity and are already familiar with this challenge. Yet, you may be far less familiar with the conditions informing the underlying American social psychology. At this time, I think it’s professionally prudent to inform yourself. So let’s take a look…

To the data…

There have been numerous polls over many years asking Americans about their global warming beliefs and attitudes. You may be surprised that a majority of Americans report that they actually do believe warming is occurring. This finding is consistent across polling questions and pollsters (with variation attributed to how the question is asked). Notably, there has been minimal change over time in these numbers.

Is Global Warming Happening

Underneath this static surface of stable beliefs, though, there have been significant changes in American attitudes. A majority may believe the Earth is warming, but a much smaller fraction of Americans also express serious concern about anthropogenic climate change (39%). This proportion has remained virtually unchanged for 13 years. Far more frightening is that over this same period, the fraction of Americans reporting they are unconcerned because they deny or are skeptical about climate change has more than doubled. Trebling from 12% in 2001, skeptics now make up a quarter of the U.S. public.

Gallup Global Warming Opinion Groups

It is critical that we pause and recognize the situation we, in the climate change community, find ourselves. Almost two decades of new scientific evidence, combined with international reports and studies (most of which almost no one reads), international conferences and meetings—all followed up with education and advocacy campaigns—appear to have only expanded and entrenched the population that denies the significance of the issue.

How can Americans believe in global warming but then be unconcerned by it?

Americans have actually become less convinced that climate change is anthropogenic in origin. While the numbers of Americans believing in climate change have held steady, the number attributing warming to “natural causes” has been on the rise. Against the backdrop of decades of concerted outreach and communication of scientific consensus that dispels the “its natural” theory, this is a depressing result.

Is There Solid Evidence the Earth is Warming
Perceived Cause of Global Warming

More Americans are also certain about their climate change beliefs. Over the last decade, Americans have both become more convinced and more confident that their beliefs are based on a good understanding of global warming.

A challenging environment

But even acknowledging these challenges, an optimist may say that the situation is not so bad. After all, almost 40% of Americans say they are concerned about climate change, while another third I would guess is mostly just not paying attention. Get some of those that don’t care about the issue to start paying attention and we’re good. Right?

Let’s take a look behind the numbers. First, it’s important to be very clear that historically, Americans do care about the environment. The U.S. public has continued to support environmental laws on air and water pollution, not to mention the precedent setting conservation measures associated with our national parks and wilderness lands systems. Opinion polls show that Americans continue to be concerned about these local environmental issues.

Unfortunately, for a variety of reasons it seems that this environmental sensitivity has not crossed over to climate change. In fact, on climate, the situation in the United States is actually pretty bad. Put simply: Despite the fact that the majority of Americans express some amount of worry, the average American is not yet seriously concerned about climate change enough to rank it as a priority issue.

Global Warming a Threat in Your Lifetime
Global Warming is Seen as a Relatively Distant Threat

Where is this lack of concern coming from? Interestingly, it is not highly correlated with age, education, income[1], or even region of the country. And while we do see some temporal patterns in these surveys, these probably reflect the economic roller coaster ride starting in 2007. Also we must recognize that these polls have been taken in the wake of the focus on terrorism since 2001. Though you can’t poll the counterfactual, absent these two major events, I doubt we would have observed radically different trends than we currently see.

In sum, the data drives us to a few conclusions. One, that efforts to help Americans understand the science and impacts of climate change have not only been ineffectual, but appear to have been counterproductive. Two, that the majority of Americans are just not concerned with climate change nor do they see it as an imminent threat. And perhaps most disconcerting, the variable that is highly correlated with current American attitudes about climate change is political party affiliation!

Tribal warfare

For several decades, Americans have been sorting themselves ideologically into political parties. Historically, political parties in the United States had significant overlap in ideology—you could find many Republicans and Democrats that would agree on any given issue. But, such overlap is no longer present. An individual’s position on major “hot button” issues is now tightly connected with political party affiliation. Particularly among the political “right” (i.e., Republicans and the “Tea Party”), political parties increasingly exhibit tribal tendencies.

Percentage who believe the Earth is warming
What's causing global warming

Even more troubling, a component of these trends is a growing distrust in science itself, driven largely by changes in the beliefs of Americans with a conservative tribal identification.

How much do you trust what scientists say about the environment

Washington Post-Stanford University poll conducted June 13-21, 2012 among 804 adults.


So we have a big problem. International collective action on GHG emissions is contingent upon U.S. action and leadership. Yet, Americans are a statistical outlier in their belief and concern about climate change.


How the world sees climate change

And this outlier status appears largely explained by a new level of tribal-ness in American politics and one party’s attachment of group identity to an anti-science view on the issue.

Differing views on climate threat

Education makes us more stupider[2]

The failure of education and information campaigns to shift public opinion in the United States is challenging some old social psychology assumptions. Research shows that people will resist acknowledging information or evaluating evidence presented to them if it appears to conflict with pre-existing beliefs on issues deemed important. Group or tribal affiliation strongly affects which issues are viewed as important. Tribal (in this case political party) affiliation produces strong biases that short-circuit people’s ability to rationally evaluate and even acknowledge credible evidence. This research explains what we saw in the polling data—attempts to educate people on an issue linked to tribal affiliation actually reinforces their rejection and disregard of that issue. The exact opposite of the intended effect.

You can observe this psychological phenomenon not only with political conservatives, but also with many on the political left on issues such as geoengineering. Our brains eagerly discredit messengers and turn off rational processing of evidence in favor of preserving trial identity and cohesion. This phenomenon has been labeled “Identity-Protective Cognition” or the “smart idiot effect.” It is easy to see how it would be evolutionarily advantageous for humans to bias their beliefs so as to better enhance group or tribal cohesion.

With American conservatives, though, this psychological mechanism seems to be more predominant and takes a particularly pernicious form, as it is often combined with a religious conception of the environment—the belief that divine intervention will sustain the Earth in a condition that will continue to be ideal for humans. In other words, there is a strong tendency in American religiosity—and Americans are uniquely religious in the developed world—that rejects the possibility of global environmental changes and related scientific conclusions. So, as science embraces the Anthropocene paradigm, there is a growing rejection of the science underpinning this paradigm by a significant fraction of the American public. This dynamic should frighten all of us and may portend future conflicts.

When tribal warfare becomes a civil war

Earlier this year, Christopher Hayes wrote a controversial and fascinating article juxtaposing the political economy of the climate issue with that of slavery and the American Civil War. He rightly was careful to distinguish the moral repugnancy of treating human beings like property from the moral quandary of emitting GHGs. His comparison instead focused on the role both slavery and fossil fuels play in the economy of each period and functioned as sources of energy for production. Not only was the economy of the southern United States built on slave labor, but so was much of the personal wealth in the South. The movement to abolish slavery in the United States demanded that this claimed wealth (in the form of slaves that at the time had a market value) be forfeited. The conflict was only resolved through a bloody civil war.

Now similarly imagine how much wealth is tied up in fossil fuel reserves and capital dependent on continued consumption of those reserves. Taking climate change seriously demands that much of that booked wealth be forfeited. Americans are currently celebrating cheap energy in the form of new drilling technologies for petroleum and natural gas that are expanding domestic reserves. Fossil fuel companies continue to invest heavily in exploration and development of future supplies and reserves. These are not the signs of a society ready to walk away from so much perceived wealth.

OK, how do we fix it?

Hayes sees hope in the climate-focused divesture movement. I am pessimistic that this strategy will have a significant effect unless backed by governments and based on the ambiguous record of socially responsible investing.

Others continue to champion public education campaigns and scientific reports that unproductively attempt to scare and inspire at the same time. There are good reasons to do more science on climate change. But, as I discussed above, I don’t think it would be wise to expect further scientific data or predictions to produce political change.

Again, an individual’s ability to rationally consider evidence seems to be determined by whether their tribal group has a firm position on the issue. Unfortunately, climate change is now firmly affiliated with tribal identity in the United States. Therefore, efforts to shift U.S. public opinion must separate the issue of climate change from its tribal association, especially within American conservatism.

How might this separation be achieved? To be honest, I really don’t know. (But I am pretty sure, it is not by focusing on cosmetic things like tweaking our terminology.) Is there an alternative public outreach strategy that might work? I hate to throw cold water on the campaigners out there, but I doubt this is a path to success.

My intuitive assessment, as I have said previously, derives from spending the first half of my life in isolated regions of Texas that were both politically and religiously conservative. My sense is that climate change will only become a majority concern and priority for the American public when it manifests as an imminent threat to the people and places they care about, which is sadly an obvious insight that comes without a solution.

The tragic aspect of my assessment is that the nature of the climate change problem does not lend itself to a last minute clean-up. It seems that the impacts of climate change will need to become dire enough to overcome the loss aversion associated with giving up all that fossil fuel wealth. Abolishing the burning of fossil fuels may yet lead to a war, amongst ourselves, with the planet, or both. I certainly hope I am wrong and that we see a wave of prominent conservative leadership that finds the courage to pry away climate change denial as a measure of tribal identity.


Further reading

Climate Change: the Slippery, Shape Shifting, Jelly Mold Threat,” Climate Change Denial, George Marshall, August 20th, 2014.

Republicans’ Lukewarm Climate Warrior,” Bloomberg View, Christopher Flavelle, August 18th, 2014.

Climate Change in the American Mind,” Yale Project on Climate Change Communication and the George Mason University Center for Climate Change Communication, April 2014.

[1] Concern for climate change is negatively correlated with one group of Americans: political conservatives. Higher income Republicans are more likely to dismiss climate change than lower income Republicans.

[2] Given that the mission of the GHG Management Institute is largely educational, it is appropriate for me to focus briefly on the role of education in shifting public opinion. But first let me distinguish the mission of the Institute. Information campaigns on climate change are intended to change public opinion. In contrast, it is the mission of the Institute not to change the opinions of the masses. It is to advance the professional development of those working to address the causes of climate change.

20 responses to “Why do so many Americans deny climate change?”

  1. Joe Abraham says:

    Nice article Michael. would you let me know if you are ever in the PNW, especially in Portland, so I can see if you would be willing to give a talk at Willamette University (45 min south in Salem, the state capitol)? I am the lead staff here on our commitment to carbon neutrality (ACUPCC), which is a long game, and work with faculty to use our commitment and science to teach our students. I was at the University of Arizona previously where I finished a PhD on vulnerability to climate variability and change, including working at the interface of climate science and policy. -Joe

    Joe Abraham, Ph.D.
    Willamette University Sustainability Institute
    and Zena Forest & Farm
    Salem, Oregon
    (503) 370-6482
    [email protected]

  2. John Collins says:

    Thanks for this very informative article. Communication science tells us that people believe who we trust. That chimes with your ‘tribal’ affiliation angle. I’m inclined to share your pessimistic conclusion. On the positive side, America can move fast when it really wants to. Churchill said “You can always count on Americans to do the right thing – after they’ve tried everything else.”
    John Collins
    Instructor in Sustainable Living, Maharishi University, Fairfield IA
    PS I’m a Brit

  3. Dylan Kruse says:

    You’re a solid writer, and you cover really interesting topics. One of the few blogs I regularly read.

  4. Michael Gillenwater says:

    Joe, thanks for the kind words, and I have sent you an email about options for coming down to Willamette.

    John, yes that is what is fascinating is that the tribal effect can even lead people to distrust scientists (albeit selectively by issue). As I stated, this is a very disturbing trend for the future.

    Dylan, thank you for the kind compliment.

    – Michael

  5. Alok says:


  6. Steve says:

    I firmly and whole heartedly believe that the climate of our planet is changing, as do many Americans. However, during our lifetime we have seen changes occurring and they change slow enough that we can adapt. It does not feel like a threat. I believe that the climate has always been changing and the rate of change is what most mean when they try to communicate that there is a problem to solve. The other thing that is difficult to believe is that man can be the source of the climate change, since it has always been changing and the rate of change being abnormal is nearly impossible to show or prove. Action to stop something that is not well demonstrated or understood, is hard to do. Prove to me that man can fix this, without a shadow of a doubt and I’d be all in. Until then, call me a denier, because I also firmly believe that we have not caused this we are just witnessing it happen. The climate on the Earth has been much cooler over time (numerous glacial periods) and it has been much warmer, the age of the dinosaurs. How is this new change any different?

    • Jason says:

      It’s not that change doesn’t always happen. We never have the same weather all the time. But it’s the trends (warmer)and the rate of that trend that is the alarming part. That’s why we use science and technology to monitor and record what is happening in the past 100+ and where it is going that is the alarming part. We tend to ignore or discredit any facts because we don’t see any drastic effects of this change in our own backyards many times. But once we do it will likely already be too late to fix the problem. I don’t ever remember have air quality action days here in the US until the last 5 years or so.

  7. A different Steve says:

    Thanks for the article. The section on discrediting messengers from the ‘other side’ answered something I have wondered about.

    The political split interesting and as I am not American wondered if some Republicans have been progressive on climate change? In particular I thought California had shown on leadership on renewable energy under Republican governance?

    I would be interested to see similar analysis in Australia and suspect that the biggest factor affecting attitudes to climate change was a severe drought that ran from about 2001 to 2007. Since we have been getting rain again (in the cities at least) people seem to be less concerned about the impacts of climate change.

  8. Michael Gillenwater says:

    Here is a more nuanced view on the broader issue of science denial looking at several issues and their prevalence in both politically conservative and liberal populations in the USA.


  9. Michael Gillenwater says:

    And here a small data comment on the relationship between race and concern for global warming. The data raises more questions than it answers, but they are interesting questions.


  10. Michael Gillenwater says:

    Here is a nice sample of public positions by current Republican national candidates.


  11. Michael Gillenwater says:

    Here is a great post based on work from Yale University researcher Dan Kahan about the role of religion versus partisan (tribal) affiliation in beliefs on climate change.


    This data seems to support my discussion in this blog post.

  12. Stefan Björklund says:

    I think this development with a slight warming is very good. In Scandinavia the harsh winter is a health problem, many of us therefore like to fly away to warmer places like Spain or Thailand. We have had many years now with to much snow. But the last summer very good, some days over 30°. I hope this trend will continue.

    There have over years been a lot of scary stories from our government about a warming world, but most people understand that climate science is all about rising new taxes. And we have got enough of high taxes. Bert Bolin proposed a carbon tax already 1986. Therefore they created the IPCC.

    Svante Arrhenius, the Swedish, who got the Nobel Prize in chemistry, and who started study global warming, already in a speech at Stockholm University 1896 said, a slight warming, up tp 6°C, would be very beneficial for Sweden and Norway.

  13. Pierre Boileau says:

    Hi Michael,

    Thanks for this excellent article. It is well researched and covers a difficult topic about the tribalism of American politics and its effect on the views of the public about climate change. I did want to try to simplify the science for some who may be reading, because this was done for me a few years back and it really helped solidify my understanding of human impact on climate. There are three basic scientific observations that link today’s observed climate change to human activity:

    1. The historical temperature record and ice core data show a clear correlation between temperature increases and increases in CO2 concentrations in the atmosphere. When temperature goes up, so does CO2. This is mainly the result of more biomass growth and decay, from the increased temperatures. Now, since a correlation implies that the reverse is true, then when CO2 concentrations go up, so should the temperature. However, a correlation doesn’t identify the cause, so we need to go further in our analysis.
    2. The atmospheric concentration measurements of CO2 that started back in the 1950s and those taken from ice core measurements show that CO2 concentrations have never been this high before and the growth trend in CO2 concentrations has never been this steep. This finding correlates well with the observed average temperature increases, since they have also been rising, even though they may have paused recently. Therefore the correlation mentioned in point 1 would tend to make us conclude that if CO2 concentrations continue to increase then temperature will continue to increase and this will add increased ‘energy’ to the atmosphere, leading to the already observed climate impacts and the projected impacts of climate change.
    3. So far we haven’t discussed the link to human activities, but this is fairly easily confirmed by carbon dating the samples that were collected in point 2. If the carbon dating evidence shows that the CO2 increases are primarily from ‘young’ carbon, we can assume that a good portion of the CO2 in the atmosphere is due to biomass growth and decay, which would put it in the ‘natural event’ category. However, when researchers do the carbon dating of these samples they find that the CO2 is mainly from ‘old’ carbon, or carbon that results from the combustion of fossil fuels (which have been in the ground for millennia, and therefore the carbon-dating signature is quite old). This leads to the conclusion that the CO2 we are adding to the atmosphere is primarily from human activities of extraction and combustion of fossil fuels, thus the climate change we are observing now and are likely to observe in the future is the result of human activities.

    I hope that’s helpful to the discussion. Regards


    • Michael Gillenwater says:

      Thank you for the careful decomposition of the fundamental evidence. Those of us in the community often take these facts as givens, but clearly, as the surveys show, there is a lot of ignorance out there.

  14. Michael Gillenwater says:

    Here is a good supporting study that finds the same social dynamic occurring with the issue of fracking.



  15. Michael Gillenwater says:

    And another example of cognitive bias attributable to political/tribal affiliation.


  16. Charlie says:

    I live in a conservative community with a large corporate presence. Also highly educated engineers, etc. In my conversations with reasonable people, who happen to be conservatives, and deny climate change science, they invariably reference “funders of the studies” as why they don’t believe them. How would you address that concern?

  17. Ange,
    Thank you for your feedback. And, yes, these conversations can be difficult as many people take this issue as one of identity, rather than evidence.

  18. Charlie,
    The social science shows that more education is correlated with higher levels of resistance to evidence. Look at the literature on motivated reasoning. The more you know (e.g., have science education) seems to allow people to create more counter arguments to refute evidence. In other words, just trying to present people the evidence and “educate” them often does not work. The only thing that does seem to work, based on some limited studies, is establishing a personal relationship with them and making the difference of opinion one of social acceptance. It is a very sad commentary on humanity. That we are so irrational and really largely driven by our tribal animal brain.


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