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Climate change policy is no longer mainly a scientific issue. Political polarization, namely the huge differences between Democrats and Republicans, is the fundamental driver of viewpoints.

You can see this by looking at how opinions in Hawaii and Wisconsin break down on nifty new mapping software that includes unprecedented public opinion data about climate change. It’s now possible to see how people in every county and congressional district think about a whole variety of climate change issues.

The Yale Climate Opinion Maps are .ÌýBut the maps are also limited and can be misleadingÌýbecause they underemphasize polarization’s influence at the national level.

And that is where the action is right now because of the new Obama global warming plan, the most important climate change policy in many years.

The , technically a series of Environmental Protection Agency regulations, requires power plants to get a certain percentage of their power from renewable sources.ÌýThe regulations also require power plants that use coal to reduce their carbon dioxide emissions by a specific amount.

The maps stress variations within states and difference among racial and ethnic groups.ÌýInteresting, but they ignore the fundamental fact that people who call themselves Democrats are much more likely to consider climate change a problem than Republicans are.ÌýThese differences are stark and growing.

Let’s take a look at four pieces of evidence that show how important polarization is.

Hawaii is an outlier when it comes to public opinion about climate change.

First, even the Yale maps themselves reveal polarization’s power and influence.ÌýTheÌýinformation is hidden in plain sight, requiring some well-supported assumptions.

That is where the maps’ information about Wisconsin and Hawaii come in.ÌýThey show that Hawaii is an outlier when it comes to public opinion about climate change.ÌýCompared to the rest of the nation, people in Hawaii are much more concerned about climate change and much more willing to take action.

Take one of the maps’ dozen or so measures: 76 percent of people in Hawaii are in favor of setting a standard limiting carbon dioxide emissions in coal burning power plants. Nationally the percentage is 63 percent.Ìý

The state is also different because people in each of the state’s counties respond almost exactly the same way to every question.ÌýThere are several reasons, like the entire state’s particular vulnerability or its high electricity costs.ÌýBut it is safe to assume that the lack of political polarization in Hawaii is a key reason for this unity.

Hawaii, after all, is overwhelmingly Democratic.ÌýThere are not enough Republicans or conservatives to create diversity on the map. Political homogeneity and climate change homogeneity go hand in hand.

Wisconsin is one of the most politically polarized states in the country.ÌýOnce more the maps don’t highlight this, but a look at a few Wisconsin counties more than hints at the difference that polarization makes.

Waukesha County, the most Republican in the state, adjoins or is very close to two of the most Democratic counties, Milwaukee and Dane.ÌýOn the maps, Waukesha is below the national average on almost every one of the climate change opinion measures, while Milwaukee and especially Dane County are above the average on almost every measure.

The country as a whole is much more like Wisconsin than like Hawaii.

Second, research consistently shows that polarization is getting more pervasive.ÌýThe ideological and partisan divide is bigger than ever.

This goes well beyond politics. Democrats and Republicans are increasingly more likely to live in separate neighborhoods, use social media in different ways, and have increasingly hostile views of those politically on the opposing side.

Third, this polarization dominates views about climate change.Ìý

A Ìýshows how great the ideological divide is on the most basic global warming issue.

In that poll, 76Ìýpercent of the liberal Democrats and 60 percent of moderate Democrats felt that global warming is a serious problem.Ìý In contrast only 36 percent of those who called themselves the moderate Republicans and a miniscule 14 percent of conservative Republicans thought so.

A taken after Obama announced his power plant regulations showed that 78 percent of the Democrats approve of setting strict standards for power plant emissions while barely half the Republicans and only about a quarter of Tea Party Republicans want these regulations.

In fact, climate change skepticism is increasing among the most solid Republican constituencies: men, older people, whites and evangelicals. Other studies have shown that even highly educated Republicans are less likely to view global warming as a problem.

Fourth, there are clear reasons why this polarization is likely to increase on climate change matters.ÌýIncreasingly people pick up cues and opinions about climate change from politicians and political parties they support.

Democrats and Republicans are increasingly more likely to live in separate neighborhoods, use social media in different ways, and have increasingly hostile views of those politically on the opposing side.

In this way climate change opinions develop the same way that views of other public health matters do.ÌýOnce these become political issues, partisan cues take charge. Science takes a back seat to politics.

And that is exactly what is happening regarding President Obama’s recent climate change policies.ÌýPolitical cues are all over the place.ÌýAmong the public, Democrats and Republicans will take their cues from totally different sources.

The more the visibility, the more likely people are to see the issue in terms of their political ideologies. Republicans will become less supportive of power plant regulation and renewable energy requirements while Democrats will become more in favor of them.

Waukesha will become even less like the two Democratic Wisconsin counties and Hawaii.

As the Yale map creators and others have pointed out, much if not most of the climate change action takes place at the state level.ÌýHawaii is certainly an example of this.Ìý

So, as the researchers who did the study say, having this information about divisions within a state could help state policymakers.

ButÌýa state-by-state approach has important limitations.Ìý

Statewide policies are limited because, well, because they apply only statewide.ÌýNews flash: Coal states like Sen. Mitch McConnell’s Kentucky are not going to set .

Obama and other supporters of national climate change standards, or for that matter their opponents, are not going to spend time combing the Yale maps for insights. They know that only one insight really matters: Democrats support climate change policies, while Republicans don’t.ÌýThose differences are stark and getting starker.

In a political process designed to enhance polarization, that makes all the difference.