Residents of Ann Arbor, Michigan, and Corvallis, Oregon, are far more likely to believe that global warming is happening than people in Casper, Wyoming, and Dothan, Alabama.

These findings can be explored in a new study and interactive tool that, for the first time, allows users to drill down from national-level to congressional-district level survey results on global warming beliefs.

The study estimates that a majority of adults in all states believe that global warming is happening, ranging from lows of 54% and 55% in West Virginia and Wyoming, respectively, and highs of 75% and 81% in Hawaii and the District of Columbia.

However, in many states, there is no majority consensus about whether global warming is caused mainly by human activities or whether most scientists think global warming is happening. This is even the case in some threatened coastal areas, such as parts of Louisiana, where sea level rise and land subsidence is causing a football field’s worth of land to disappear each day.

Screenshot from the climate opinion model's interactive tool, showing Alabama's 4th congressional district outlined in red.

Views within states can vary wildly

The study also estimated that in 75 out of the 3,143 counties in the U.S., less than 50% of people believe that global warming is happening.

In Trimble County, Kentucky, for example, an estimated 43% of people believe that global warming is occurring; in New York County, New York (which includes Manhattan) that number is estimated to be far higher, at 80%.

On a separate question measuring concern about global warming, the study found that 52% of Americans overall are worried about it. But on a local level, the views on this question swing wildly from an estimated low of 38% of the public in Pickett County, Tennessee, to a high of 74% in Washington, D.C.

The results also identify important variations within states. In Texas, public worry about global warming ranges from a low of 39% in King County to a high of 61% in Travis County.

“These [intrastate] differences are partly due to the fact that different groups often think differently about the issue,” the lead author of the study, Peter Howe, of Utah State University, said in a press release.

“For example, Hispanics and Latinos tend to be more worried about global warming than other racial or ethnic groups, which can be seen on the map in counties with more Hispanic and Latino residents,” he added.

The study helps explain some of the divisions on climate issues seen on Capitol Hill.

Congressmen reflect their districts

Republican Rep. Robert B. Aderholt represents the fourth district of Alabama, the congressional district with the lowest percentage of people who say they are worried about climate change (40%), as well as the lowest percentage of people who say global warming is happening (52%). Perhaps not surprisingly, Aderholt has a 4% lifetime score from the League of Conservation Voters (LCV), an environmental group.

Other districts with relatively low support for mainstream climate science findings are located in coal-producing or burning states, such as Ohio, Kentucky, Tennessee and Wyoming.

On the other hand, freshman Democratic Rep. Donald Beyer represents a district with extremely high support for the existence of global warming, at 76%. That district borders the nation’s capital, which has an even higher percentage of people supporting that global warming statement (85%), but lacks a voting representative in Congress.

Like Adherholt, Beyer's policy stances reflect his district's views. He recently issued a statement supporting President Barack Obama’s submission to the U.N. of plans to cut greenhouse gas emissions by 26% to 28% below 2005 levels by 2025.

“Global climate change is the existential crisis of our time. I am proud to see President Obama’s pledge that the United States will take a leading role on the international stage to protect our environment,” Beyer said.

The LCV has not yet assigned a rating for Congressman Beyer.

A method to the madness

The data comes from a dozen national-level polls conducted by Yale University and George Mason University between 2008 and 2013.

For the new study, published in the journal Nature Climate Change on Monday, researchers at Yale and Utah State University used statistical analysis techniques to estimate locally relevant information about public opinion on global warming.

The study uses methods similar to how climate scientists scale down results from global climate models, which provide information at broad geographic scales, so that they shed light on changing conditions in smaller areas.

“Most of the action to reduce carbon pollution and prepare for climate change impacts is happening at the state and local levels of American society," said Anthony Leiserowitz, of Yale University, in a press release.

“Yet elected officials, the media, educators and advocates currently know little about the levels of public and political will for climate action at these sub-national levels. State and local surveys are costly and time intensive, and as a result most public opinion polling is only done at the national level. This model for the first time reveals the full geographic diversity of public opinion in the United States at these critical levels of decision making.”

The results show some surprises. For example, although 63% of Americans believe global warming is happening, county-level analyses of the same question range from 43 to 80%, with the highest level of support found in metropolitan areas of traditionally “blue” states, such as California and New York.

The study drives home the point that any prospective climate policies that have to wind their way through state legislatures or Congress would face a complex geographical diversity of viewpoints on how significant a threat global warming is, and possibly the existence of the problem in the first place.

This became clear during congressional debate on a 2009 climate bill that passed in the House and failed to make it through the Senate. In the House, many Democrats from coal-producing states or states dependent on coal-fired power plants for electricity and industrial activities wavered in their support of the bill, since their states would have seen higher electricity costs and other penalties if such a bill becoming law.

Since that bill, known as the Waxman-Markey bill in the House, failed, and Republicans took the majority in both houses of Congress, President Obama has pursued a strategy of enacting unprecedented climate regulations using his executive authority. This includes the EPA’s Clean Power Plan and other policies aimed at cutting emissions of planet-warming greenhouse gases.

Public opinion on small scales

Because the study did not actually involve surveys conducted in every county or congressional district, since that would be “prohibitively expensive,” the study asserts, the margins of error are slightly higher than they might be for traditional opinion surveys.

The margins of error average plus or minus five percentage points for state-level models, with higher margins of error at the county level (plus or minus eight percentage points), and plus or minus seven percentage points for congressional district-level data. Overall, the accuracy of the model estimates is higher for geographic areas with larger populations, the researchers say.

To validate the model, the researchers conducted separate surveys in four states and two cities. They found that the model-based estimates were within three percentage points of the independent surveys at the state level and four percentage points at the city level.

Even factoring in these error ranges, the polling data offer important and original insights about the geographic distribution of Americans' opinions on global warming. They provide a road map of sorts for advocacy groups seeking to push forward with — or hit back against — global warming-related policy measures.

One overall lesson that emerges is that, at a national level, there is already more than enough support for certain actions to combat global warming, such as encouraging renewable energy use by mandating that states obtain a particular percentage of their electricity from solar, wind and other renewable sources.