Yale Program on Climate Change Communication

1. Global Warming Beliefs

1.1. Most Americans think global warming is happening.

Americans who think global warming is happening outnumber those who think it is not happening by a ratio of nearly 5 to 1.

About three in four Americans (74%) think global warming is happening. By contrast, only 15% of Americans think global warming is not happening. Eleven percent say they don’t know if global warming is happening (refer to data tables, p. 31).

1.2. When Americans who “don’t know” if global warming is happening are asked for their best guess, more say “yes” than “no.”

Survey respondents who say they “don’t know” whether global warming is happening in response to the question in Section 1.1 (refer to data tables, p. 31) are then asked to provide their best guess as to whether or not global warming is happening. Over time, this follow-up question has produced a relatively stable pattern in which more of these Americans “lean” toward “yes” than “no” (refer to data tables, p. 32).

When the “leaners,” as determined by this follow-up question, are added to the totals of those who responded “yes” or “no” to the question in Section 1.1, we find that a total of 82% of Americans think global warming is happening or lean toward that position, while 18% think global warming is not happening or lean toward that position.

1.3. About half of Americans are “extremely” or “very” sure global warming is happening.

About half of Americans (53%) are either “extremely” or “very” sure global warming is happening. Far fewer (8%) are “extremely” or “very” sure global warming is not happening.

1.4. A majority of Americans think global warming is mostly human-caused.

The Intergovernmental Panel on Climate Change’s Sixth Assessment report, written and reviewed by thousands of climate experts worldwide, states: “It is unequivocal that human influence has warmed the atmosphere, ocean and land.”Intergovernmental Panel on Climate Change. (2021): Summary for Policymakers. In Masson-Delmotte, V., Zhai, P., Pirani, A., Connors, S. L., Péan, C., Berger, S., Caud, N., Chen, Y., Goldfarb, L., Gomis, M. I., Huang, M., Leitzell, K., Lonnoy, E., Matthews, J. B. R., Maycock, T. K., Waterfield, T., Yelekçi, O., Yu, R., & Zhou, B. (eds.), Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press.

A majority of Americans (61%) understand that global warming is mostly human-caused. By contrast, 28% think it is caused mostly by natural changes in the environment.

1.5. A majority of Americans understand that most scientists think global warming is happening.

A review by Cook and colleaguesCook, J., Oreskes, N., Doran, P. T., Anderegg, W. R. I., Verheggen, B., Maibach, E. W., Carlton, J. S., Lewandowsky, S., Skuce, A. G., Green, S. A., Nuccitelli, D., Jacobs, P., Richardson, M., Winkler, B., Painting, R., & Rice., K. (2016). Consensus on consensus: A synthesis of consensus estimates on human-caused global warming. Environmental Research Letters, 11(4). doi:10.1088/1748-9326/11/4/048002 found that six independent, peer-reviewed studies examining the scientific consensus about global warming have concluded that between 90% and 100% of climate scientists are convinced human-caused global warming is happening. A more recent study found that as many as 98% of climate scientists are convinced global warming is happening and human-caused.Myers, K. F., Doran, P. T., Cook, J., Kotcher, J. E., & Myers, T. A. (2021). Consensus revisited: Quantifying scientific agreement on climate change and climate expertise among Earth scientists 10 years later. Environmental Research Letters, 16(10). doi:10.1088/1748-9326/ac2774

A majority of Americans (58%) understand that most scientists think global warming is happening. This percentage has trended generally upward since this survey began in 2008. By contrast, about one in five (22%) think there is a lot of disagreement among scientists about whether or not global warming is happening. Very few Americans (2%) believe most scientists think global warming is not happening.

1.6. One in five Americans understand that almost all climate scientists (more than 90%) have concluded that human-caused global warming is happening.

Although the majority of Americans now understand that most scientists think global warming is happening, fewer understand just how strong the level of consensus among scientists is. Only one in five Americans (20%) understand that nearly all climate scientists (more than 90%) think that human-caused global warming is happening.Respondents were asked to estimate the percentage of climate scientists who have concluded that human-caused global warming is happening by moving a slider bar which appeared on the screen of their computer. This slider allowed respondents to move the marker from 0% on the left to 100% on the right, or to any whole number between the two. A “don’t know” response option appeared below the slider bar. A similar percentage of Americans (22%) say they “don’t know” what percentage of climate scientists think human-caused global warming is happening.

Public misunderstanding of the scientific consensus – which has been found in each of our surveys since 2008 – has significant consequences. Other research has identified public understanding of the scientific consensus as an important “gateway belief” that influences other important beliefs (i.e., that global warming is happening, human-caused, and worrisome) and support for action.For more information, refer to van der Linden, S. L., Leiserowitz, A. A., Feinberg, G. D., & Maibach, E. W. (2015). The scientific consensus on climate change as a gateway belief: Experimental evidence. PLoS ONE, 10(2). https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0118489