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What do Americans think about global warming?  Do people believe that the Earth has been warming?  Do people believe that human activity has contributed to warming?  Do people believe that warming constitutes a threat?  Do people want government to do anything about the issue?  Do people attach any priority to the issue?  Do people’s opinions on the issue influence their voting behavior?  Are people willing to pay money to reduce future emissions?

Since 1995, Stanford’s Political Psychology Research Group (PPRG) has been exploring these issues through a series of high-quality national surveys of random samples of American adults.

Co-led by Jon Krosnick (a Stanford professor with expertise in public opinion, political psychology, and survey methodology) and economist Bo MacInnis, the PPRG team has partnered with many major news organizations in conducting the surveys and releasing their findings.

This website describes those findings, beginning with this page, which offers a general overview of the research effort.

The Issue of Global Warming

During the 19th century, natural scientists observed what was ultimately called the “greenhouse effect”, and in 1965, President Lyndon Johnson’s Science Advisory Committee predicted that by the year 2000, rising carbon dioxide levels would “almost certainly cause significant changes” in temperature and stratosphere properties. In 1988, the issue burst onto the front pages of newspapers when James Hansen, head of NASA’s Goddard Institute for Space Studies, told Congress that the greenhouse effect was, in fact, warming the Earth (1,2).

The Intergovernmental Panel on Climate Change (IPCC), created that year by the United Nations and the World Meteorological Association, has issued increasingly strong statements about global warming over the years. In 2014, the IPCC said that the “warming of the climate system is unequivocal” and anthropogenic. And scientific academies in various nations have urged “prompt action” by governments to reduce greenhouse gas emissions (3,4).

Governments and non-governmental organizations have devoted effort to  design and implement adaptation strategies to protect people and infrastructure from possible effects of rising temperatures (5-7). And in 2015, Roman Catholic Pope Francis argued that the warming of the Earth is harming the globe’s neediest citizens and called for government policies to reduce fossil fuel use (8).  And U.S. military and national security officials have cited global warming as a national security threat for the United States and the world and have been taking steps to prepare for increased temperatures (17-18).

At the same time, skepticism about these issues has been regularly expressed by individuals and organizations in many quarters. U.S. Congress members, presidential candidates, think tanks, and others have suggested that warming may not be happening, or may be natural rather than human-caused, and that taking action to reduce greenhouse gas emissions would be counterproductive (9-16).  For example, the Cato Institute has challenged the claim that the effects of warming will be catastrophic (14). Likewise, the Heartland Institute has disputed the claim of consensus among natural scientists on global warming (15).

Thus, global warming has been the subject of public debate and controversy for decades.

Informing the Discussion with Surveys

This website is intended to inform this debate by illuminating American public opinion on the issue.

PPRG’s research is inspired partly by theories of democracy that propose that a government’s effectiveness depends partly on its leaders’ having an accurate understanding of what the populace wants them to do.  Elected officials frequently receive information from lobbying groups, direct communications from constituents (through phone calls, emails, and letters), protests and demonstrations, and meetings and hearings held in their districts.

But these forms of communication may convey the opinions of only small and select parts of the population. If done well, scientific surveys have the potential to provide governments with insight into the entire population’s views and can give voice to people who don’t otherwise share their views with government. Survey research is therefore a potentially valuable tool for helping government officials understand the general public’s opinions and wishes.

Summary of Findings

During the last 50 years of serious survey research, the American public has been about equally divided on many important and controversial issues of public policy.  But global warming is unusual – Twenty years of surveys show that strikingly large majorities of Americans have agreed about whether global warming has been happening, whether it is a threat, whether it merits government attention, what policy approaches are appealing, and what policy approaches should be avoided.

The web pages reporting these findings address the following topics and others as well:

Has the Earth been warming?
Has warming been caused by humans?
Is global warming a threat?

Should Action Be Taken
Should the federal government take action?
Should other governments of other nations take action?
Should the U.S. Government act on global warming even if other countries do not?
Should U.S. businesses take action?
Should individual citizens take action?

Government Policy
How should government address global warming, if at all?  
How much effort should government devote to the issue? 
What policies should government implement to reduce greenhouse gas emissions?

Economic Side Effects
Will emissions reduction efforts hurt the nation’s economy?

Willingness to Pay
Are Americans willing to pay money in the forms of higher prices or higher taxes to reduce emissions?

How much of a priority is the issue of global warming for Americans?

Consequences of Global Warming
What might the consequences of global warming be?

Preparing For Possible Consequences
Should government prepare now to deal with the potential consequences of global warming?
What preparation measures should be implemented?

Who should pay to prepare for such consequences?

Attitude Strength
To what degree are Americans thoughtfully engaged in the issue of global warming?
How much personal importance do people attach to the issue?

Voter Behavior
Do Americans vote based on the issue of global warming?

Opinions in the States
Do opinions vary significantly from state to state in the U.S.?

Trust in Scientists
Do Americans trust what natural scientists say about this issue?

Natural Scientists’ Beliefs
To what extent do Americans perceive consensus among natural scientists studying warming?

Partisan Views
To what extent do partisans in America – Democrats, Republicans, and Independents view the issue of global warming?

Professor Krosnick summarizes many research findings in this video:


The findings presented on this website are based on studies conducted with numerous collaborating organizations and funded by a variety of organizations.

An important collaborator over the years has been the nonpartisan think tank Resources for the Future. Since the beginning of PPRG’s work in this area, RFF has provided insights into the policy-making process and into natural science findings on the issue.  Ray Kopp at Resources for the Future has been a valuable advisor and collaborator.  And RFF has provided funding to support the work.

Many of the surveys have been carried out in collaboration with some of the nation’s most respected news organizations, including The New York Times, ABC NewsTime magazine, The Washington PostThe Associated Press, U.S.A. Today, Reuters, and New Scientist magazine.  These organizations have provided funding to support the work.

Other funding has come from agencies of the federal government (the National Science Foundation, the U.S. Environmental Protection Agency, and the National Oceanic and Atmospheric Administration), private foundations (MassINC Polling Group and the Electric Power Research Institute), and academic institutions (Stanford’s Woods Institute for the Environment, the Stanford Precourt Institute for Energy, and The Ohio State University).

Data were collected by a variety of research firms: SSRS, Abt/SRBI, ReconMR, Ipsos Public Affairs, GfK Custom Research, TNS, and The Ohio State University’s Center for Survey Research.

The group’s findings have been disseminated via peer-reviewed journal articles and book chapters, news articles, press conferences, and lectures around the world.

This website is the vision of Adina Abeles, who devoted tremendous effort in collaboration with Bo MacInnis to create it, with assistance from Rita Beamish.

Additional Links


  1. Weart, S. (2003). The discovery of global warming. Cambridge, Mass.: Harvard University Press.
  2. Borenstein, S. (2015, November 4). Upcoming climate talks just the latest chapter in a long history. Associated Press the Big Story. Retrieved on November 23, 2015.
  3. Joint Science Academies’. (2005, June 07). Joint science academies’ statement: Global response to climate change. The National Academies. Retrieved on November 23, 2015.
  4. The National Academies. (2010, May 19). Strong Evidence on Climate Change Underscores needs for Actions to Reduce Emissions and Begin Adapting to Impacts. News from the National Academies. Retrieved on November 23, 2015.
  5. Beamish, R. (2014, December 23). States, Cities Brace for Global Warming Fallout. The Pew Charitable Trusts Stateline. Retrieved on November 23, 2015.
  6. Corporation for National and Community Service. Public – Private Partnership Launches New AmeriCorps Program to Help Communities Build Resilience [press release]. (2015, July 9). Retrieved on November 23, 2015.
  7. Council on Environmental Equality. (n.d.). State, Local, and Tribal Leaders Task Force On Climate Preparedness and Resilience. The White House. Retrieved on November 23, 2015.
  8. Francis, P. (2015). Laudato Si: On Care for our Common Home. Huntington, Indiana: Our Sunday Visitor.
  9. Lindzen, R. (2010, April 22). Climate Science In Denial. The Wall Street Journal. Retrieved on November 23, 2015.
  10. Gillis, J. (2012, April 30). Clouds’ Effect on Climate Change Is Last Bastion for Dissenters. The New York Times. Retrieved on November 23, 2015.
  11. EPA Administrator Gina McCarthy Testimony on Proposed Regulations. (2015, July 9). Retrieved on November 23, 2015.
  12. Idso, C., Carter, R., & Singer, F. (n.d.). Climate Change Reconsidered II. The Heartland InstituteRetrieved on Novemebr 23, 2015.
  13. Achenbach, J. (2006, May 28). The Tempest. The Washington Post.  Retrieved on November 23, 2015.
  14. Jacobson, L. (2012, May 15). On Mitt Romney and whether humans are causing climate change. Politifact. Retrieved on November 23, 2015.
  15. Bast, J., & Smith, T. (2014, May 14). Research & Commentary: The Myth of a Global Warming Consensus. The Heartland Institute. Retrieved on November 23, 2015.
  16. Gillis, J. (2015, June 26). Smithsonian Will Tighten Its Guidelines on Disclosure. The New York Times. Retrieved on November 23, 2015.
  17. Davenport, C., Haner, J., Buchanan, L., & Watkins, D. (2015, October 26). Greenland Is Melting Away. The New York Times. Retrieved on November 23, 2015. 
  18. Scarborough, R. (2015, July 29). Climate change ‘urgent and growing threat’ to national security: Pentagon. Washington Times. Retrieved on November 23, 2015.