Californians Have Reason to Believe in Global Warming

(Bloomberg Opinion) -- I was in Los Angeles and neighboring Orange County in July and it was miserably hot, much worse than I’ve ever experienced there. Sure enough, the National Oceanic and Atmospheric Administration announced this week, July was California’s hottest month on record (a record that goes back to 1895).

It was much warmer than average in July in a bunch of other Western states, too, as well as in the Northeast. Across the middle of the country, not so much:

Californians Have Reason to Believe in Global Warming

That’s just one month, of course, but NOAA’s temperature trend for California seems quite clear. It’s getting hotter there, and it has been since the 1970s:

Californians Have Reason to Believe in Global Warming

Interestingly, California also happens to be among the states with the highest share of residents (75 percent) who believe that global warming is happening, according to surveys by the Yale Program on Climate Change Communication and the George Mason Center for Climate Change Communication. The only states with a higher share of global-warming believers are Hawaii, at 78 percent, and New York, at 77 percent. NOAA doesn’t have long-run temperature data for Hawaii, so here’s New York’s chart:

Californians Have Reason to Believe in Global Warming

This also shows a pronounced rise starting in the 1970s. So that’s interesting.

Now here’s the state with the lowest percentage of global-warming believers, West Virginia (60 percent — believe it or not, the believers are in the majority everywhere):

Californians Have Reason to Believe in Global Warming

OK, temperatures have been rising lately there, too. But they also fell pretty markedly in the 1960s and 1970s, and until the past decade, one would be hard-pressed to discern much of a trend.

To see if clearer patterns could be found, I put the three states discussed above, plus the state with the next-lowest percentage of global-warming believers, Wyoming (61 percent), together on the same chart. To render them comparable, I used departures from their 1901-2000 mean temperatures, not average temperatures. And to make it a little easier to see trends, I used five-year rolling averages. The results were … not super-enlightening.

Californians Have Reason to Believe in Global Warming

Yes, Californians do have more cause to think that it’s getting warmer than West Virginians do. But Wyomansappear to have more cause to believe that it’s getting warmer than New Yorkers do. Actual climate seems to play a smaller role in determining climate beliefs than political, cultural and economic factors. It is surely not a coincidence that the four states with the lowest percentages of global-warming believers (Kentucky and North Dakota are the other two) all have a lot of people working (or formerly working, in the case of Kentucky and West Virginia’s coal miners) in fossil-fuel extraction.

Still, three Columbia University scholars did find in 2011 that people were more likely to believe in global warming if the temperature was warmer than usual on the day of the study. I would not discount the possibility that someone with more number-crunching skills and time than I might be able to tease out a modest correlation between state or local temperature patterns and belief in global warming. And I’ll admit that I want there to be such a link — it would be welcome evidence that, even on the perennially fraught topic of climate change, people are to some extent just responding to the evidence in front of them.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

Justin Fox is a Bloomberg Opinion columnist covering business. He was the editorial director of Harvard Business Review and wrote for Time, Fortune and American Banker. He is the author of “The Myth of the Rational Market.”

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