Yale Program on Climate Change Communication

1. Global Warming Beliefs

1.1. About three in four 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 more than 6 to 1.

About three in four Americans (76%) think global warming is happening, the highest percentage since our surveys began in 2008. By contrast, 12% of Americans think global warming is not happening.

1.2. More than half of Americans are “extremely” or “very” sure global warming is happening. Very few are as sure it isn’t happening.

More than half of Americans (57%) are either “extremely” or “very” sure global warming is happening, the highest percentage since our surveys began in 2008. Far fewer (7%) are “extremely” or “very” sure global warming is not happening.

Over the last five years (since our November 2016 survey), the percentage of Americans who are “extremely” or “very” sure global warming is happening has increased by 12 percentage points.

1.3. Six in ten Americans think global warming is mostly human-caused.

The Intergovernmental Panel on Climate Change’s Sixth Assessment report (2021), 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.

Six in ten Americans (60%) understand that global warming is mostly human-caused. By contrast, about one in four (27%) think it is due mostly to natural changes in the environment.

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

A 2016 review by John 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). doi10.1088/1748-9326/11/4/048002 found that six independent, peer-reviewed studies examining the extent of the scientific consensus about global warming have concluded that between 90% and 100% of climate scientists are convinced that human-caused global warming is happening. Two even more recent studies found that more than 99% of climate scientists are convinced that 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 Lynas, M., Houlton, B. Z., & Perry, S. (2021). Greater than 99% consensus on human caused climate change in the peer-reviewed scientific literature. Environmental Research Letters, 16(11). doi:10.1088/1748-9326/ac2966

A majority of Americans (59%) understand that most scientists think global warming is happening – the highest percentage since our surveys began in 2008. By contrast, about one in five Americans (21%) think there is a lot of disagreement among scientists about whether or not global warming is happening – the lowest percentage since our surveys began. Very few Americans (3%) believe that most scientists think global warming is not happening.

1.5. About one in four 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 about one in four Americans (24%) understand that nearly all climate scientists (more than 90%) are convinced that human-caused global warming is happening. However, that number has increased by nine percentage points over the last five years (since November 2016; see data tables).

The same percentage of Americans (24%) say they “don’t know” what percentage of climate scientists think 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.