Over the course of the last two weeks, two scientists -- James E. Hansen of Columbia University and Richard A. Muller at the University of California, Berkeley -- took to the pages of two prominent American newspapers to present new and compelling evidence that climate change is real, that it is driven overwhelmingly by human activity, and that its dire effects are already upon us.
And then nothing happened.
"Call me a converted skeptic," Muller wrote in an essay published July 28 in The New York Times, citing research posted, though not peer-reviewed, to the website of the Berkeley Earth Surface Temperature initiative. "Three years ago I identified problems in previous climate studies that, in my mind, threw doubt on the very existence of global warming. Last year, following an intensive research effort involving a dozen scientists, I concluded that global warming was real and that the prior estimates of the rate of warming were correct. I'm now going a step further: Humans are almost entirely the cause."
Hansen's turn came a week later. "Our analysis shows that it is no longer enough to say that global warming will increase the likelihood of extreme weather and to repeat the caveat that no individual weather event can be directly linked to climate change," Hansen declared in The Washington Post on Sunday, citing peer-reviewed work published the following day in the Proceedings of the National Academy of Sciences. "To the contrary, our analysis shows that, for the extreme hot weather of the recent past, there is virtually no explanation other than climate change."
The nation took note and then went about its business. Minds were not changed. Energy policies were not revisited in any meaningful way. And most notably, the two presidential campaigns, now rounding the final turn toward November's election, remained characteristically mute on the whole issue.
Why? Well, one reason might be that most reasonable people aren't really waiting around for more and better science to reinforce the basic mechanics of climate change. They already get it.
What ordinary Americans really want is for honest brokers on all sides to detoxify and depoliticize the global warming conversation, and then get on with the business of addressing it. That business will necessarily recognize that we all bring different values and interests to the table; that we perceive risks and rewards, costs and benefits differently; and it will identify solutions through thoughtful discussion and that crazy thing called compromise.
Dan M. Kahan, a professor of law and psychology at Yale University, has demonstrated how important it is to acknowledge differing worldviews in all this. In a study published in April in the journal Nature Climate Change, Kahan and his colleagues showed that it's inaccurate to suggest, for example, that one side of the debate simply understands the science better. Scientific literacy, the study found, is actually a poor predictor of how individuals view the climate change problem.
"Our primary insight is that there's not a kind of direct transmission of valid science to public opinion that reflects the strength or quality of the scientific evidence," Kahan said in a phone call. "Other things are involved."
The research showed, for example, that those who value both rank and individualism -- known as "hierarchical individualists" in social-science speak -- are inherently more skeptical of environmental risks. "Such people intuitively perceive that widespread acceptance of such risks would license restrictions on commerce and industry, forms of behavior that hierarchical individualists value," the researchers noted. "In contrast, people who hold an egalitarian, communitarian world-view -- one favoring less regimented forms of social organization and greater collective attention to individual needs -- tend to be morally suspicious of commerce and industry, to which they attribute social inequity. They therefore find it congenial to believe those forms of behavior are dangerous and worthy of restriction."
Kahan and his colleagues noted that the most scientifically savvy Americans -- that is, those most able to grasp the basic mechanics of global warming -- were also the most polarized on the issue.
Getting past that is no easy task, Kahan suggested, but it at least involves creating an environment where accepting scientific evidence does not define us politically. It also involves exploring a wide array of potential solutions that are prized by people of varying worldviews. In practical terms, that might mean not just condemning the evils of oil and gas companies, but highlighting the inevitable role of markets and technology and innovation in helping to curb planet-warming emissions.
In this context, Hansen, who comes with a penchant for strident activism, and Muller, whose funding sources have raised eyebrows and whose willingness to belittle his colleagues has earned him few friends, could be their own worst enemies.
Whatever the reality on that front, separating science from ideology would seem imperative. "In truth, there's no connection between what kind of person you are and the kinds of climate policies that are sensible," Kahan said. "We need to understand and make clear that the science of what's happening, and the policy options available to address it, are compatible with the commitments of diverse people."
How diverse? Anthony Leiserowitz, the director of the Yale Project on Climate Change Communication, working with researchers at the George Mason University Center for Climate Change Communication, identifies at least six distinct dispositions on the climate change question in the latest installment of the study "Global Warming's Six Americas," published last month.
The analysis has shown that the American populace tends to fall into a half-dozen categories along a continuum of concern, ranging from those on one end who are "Alarmed" by global warming to those who are altogether "Dismissive" of the issue at the other. Each group accepts, interprets, frames and prioritizes information on global warming in different ways, and understanding and accepting that diversity is a necessary first step toward reaching general agreement -- not absolute unanimity, but a consensus -- on a path forward.
"Any effort to communicate effectively needs to start with the dictum, 'first, know thy audience,' Leiserowitz said in an email message, "and this research helps to define who these different audiences are and why they interpret this issue in such different ways."
No doubt some people on the left would characterize all this as a lot of unnecessary bending over backwards to draw in stubborn or self-interested obstructionists on the right. And of course, viewed the other way, many conservatives would likely dismiss this sort of message management as so much propaganda. I asked Leiserowitz if that's what everything boils down to: peddling the science on global warming in different ways to different audiences.
"'Know thy audience' is a general rule that applies to all forms of human communication -- including with one's own friends and family members, among co-workers, teachers with their students, coaches with their players, and, I daresay, even journalists with their readers," he said. "Yes, salesmen need to know their audience or market too, but there are infinitely more types of communication that have nothing to do with buying and selling.
"In this case, if you are trying to inform 'the public' about the scientific facts of climate change, so they can make up their own mind about whether this problem exists, whether humans have anything to do with it, whether it presents a serious risk, and whether or what kinds of actions individuals or societies could take to respond, you still need to know your audience," he added. "There is no single 'American public.'"
And there's the rub.
Still, there are signs that enlightened minds are looking to move forward. One came in the form of an editorial from Fred Krupp, president of the Environmental Defense Fund, published in The Wall Street Journal on Monday. Skeptics need to stop denying the clear science, Krupp wrote, and supporters of climate action need to recognize that no policy solution can ignore the economic and market consequences that might come with it.
"We'll have a much better shot at developing solutions to our climate and energy problems that are good for our economy," Krupp wrote, "if leaders from across the political spectrum get re-engaged in the debate."
A more promising sign might have been revelations last month that a broad spectrum of thinkers and stakeholders -- left, right and center -- have been holding secret meetings on the topic of global warming under the auspices of the American Enterprise Institute, the conservative Washington-based think-tank.
Among the agenda items: finding a politically viable way to put a price on carbon emissions.
Of course, almost no one identified in the meeting program that was leaked online has agreed to speak publicly about the gathering. Until they feel safe doing so -- and until the price for reasonableness and appearing to compromise is eliminated -- we'll likely stay stuck.