Frequently Asked Questions
What do these maps depict?
The maps depict estimates of the percentage of American adults (age 18 and over) who hold particular beliefs, attitudes, and policy preferences about global warming. The estimates were generated from a statistical model that incorporates actual survey responses, but combines these responses with demographic data from the U.S. Census to estimate opinions for different groups of people based on information such as their gender, race and ethnicity, and educational attainment; they also take into account changes in public opinion over time.
Where do the survey data underlying the estimates come from?
The data underlying the maps come from a large national survey dataset ( >32,000 respondents) collected between 2008 and 2024 as part of the Climate Change in the American Mind project led by the Yale Program on Climate Change Communication and the George Mason University Center for Climate Change Communication. Reports from the individual surveys are available here: CCAM Reports.
How many people did you survey in my state/county? How can you say anything about opinions in my geography if you didn’t survey anyone there?
The number of respondents surveyed varies for each geographic unit but is very large across the U.S. as a whole. Since our surveys are nationally representative, the number of respondents in each state and county is proportional to its share of the national population. In other words, larger states and counties will have more respondents than smaller states and counties. In some smaller counties, very few, if any, respondents may have been surveyed. In those cases, our model uses information about the population of the county, information from other counties in the same state and region, and information about the characteristics of the county (such as how the county voted in previous elections) to make its estimates. While this may sound surprising, it makes sense when we consider the strongest influences on a person’s individual opinions about climate change in the U.S. – political views. Knowing the political leanings of a county’s (or other unit’s) residents, along with the proportion of different demographic groups within that county, allows us to predict resident’s climate opinions very well. Adding additional information (e.g., about rural/urban context, carbon-intensive activities, etc.), further improves predictions. Moreover, for any given geographic unit, information is pooled from nearby units and from higher-level geographies (e.g., state-level information is included for all counties within that state). All of this information together allows us to produce reliable estimates (see next question) for all counties even if the number of individuals sampled within a specific county is small.
How accurate are the estimates?
No model is perfect and there are uncertainties in the model estimates. To validate the model, we conducted independent surveys in four states (CA, TX, OH, CO) and two metropolitan areas (Columbus, OH and San Francisco, CA) and compared the survey results to our model estimates. On average, the model estimates differed from the survey results by 2.9 percentage points among the four states and 3.6 percentage points among the two metropolitan areas, within the survey margins of error. A series of technical simulations estimate that the model has an average margin of error of ±7 percentage points at the state and congressional district levels, ±8 percentage points at the metro and county levels. Such error ranges include the error inherent in the original national surveys themselves, which is typically ±3 percentage points. The model uncertainties are smaller at broad geographic scales (e.g., the state level), and are larger at finer geographic scales (e.g., at the county and city levels). The model estimates also tend to be conservative, so geographic areas with extremely high or low measures are not estimated as well as areas with values closer to the national average for each survey question.
Why are some Congressional Districts gray (missing data)?
Due to redistricting, many states have congressional district boundaries that were not yet settled at the time of census data collection, or that did not yet have census counts available for those districts. Census counts are required for the modeling, so we cannot make estimates of public opinions about climate change for geographic areas that are missing census data. We will update the model and maps as soon as the districts are settled and the census data for those areas are available. Current maps reflect all the census data available through January 2025.
What does the gray color mean on some of the bars beneath the maps?
The gray area reflects people who refused to answer the question or said “don’t know”. We do not provide specific values for the gray areas because we did not develop estimates for these particular responses.
Do the maps account for differences in population density across the country?
No, the maps depict the estimated proportion of people within each geographic area who would answer each question as indicated. We have not adjusted the maps based on population density differences. It is important to keep in mind that some geographic areas may be large, but have few residents (e.g., Wyoming), while other geographic areas may be small, but have many residents (e.g., New Jersey).
Do these maps reflect changes in opinions due to recent extreme weather events like Hurricane Helene?
Perhaps. The maps may reflect the impacts that specific extreme weather events had on public opinion in a given geographic unit. If public opinion in a particular area has been influenced by local events it is possible that the model would detect such an influence. However, data from specific events or types of events are not explicitly built into the model as predictor variables.
Can I use the data?
Yes. We encourage you to explore the maps and use the results in your own work. The data are available on our Data Download tab at the top of this page so that you can do your own analyses and create your own visualizations. If you publish an academic paper using these data please acknowledge the source by using the following citation:
Trends over time from 2010–2020 are provided for 16 state-level climate opinions using data from Marlon et al. (2022). Estimates for 2021, 2022, 2023, and 2024 are generated using our conventional MRP model described in Howe et al. (2015).
Marlon, J. R., Wang, X., Bergquist, P., Howe, P., Leiserowitz, A., Maibach, E., Mildenberger, M., and Rosenthal, S. “Change in US state-level public opinion about climate change: 2008–2020.” Environmental Research Letters 17, no. 12 (2022). 124046.
Howe, P., Mildenberger, M., Marlon, J., & Leiserowitz, A. (2015) “Geographic variation in opinions on climate change at state and local scales in the USA,” Nature Climate Change 5. DOI: 10.1038/nclimate2583.
If you publish a news article, visualization, blog post, or other publication using these data or maps, please include the link to the Yale Climate Opinion Maps website and attribution to the Yale Program on Climate Change Communication.