Imagine two people, A and B, in a room. There’s a bird in the room – at least, A says there is. B says there isn’t. This bird is flying around the room in plain sight, so it would be difficult to miss it. One can see it with one’s own eyes – at least, A says this. B denies it. Now, you might wonder if there’s a problem of definition. Maybe they both see something flying around the room, but A thinks it’s a bird, while B thinks it’s a bat. Let’s assume, for the sake of discussion, however, that that’s not the issue – it’s clearly a bird; it has all the classic features of a bird; in fact, it’s obviously a common bird – a robin, say. That is, if you agree that it’s there at all.
If you were an observer of this situation and you saw the bird, you would probably conclude that B is either lying (he sees the bird but won’t admit it) or crazy. (We’ll rule out the possibility that he’s blind, since he can see A just fine.) There doesn’t seem to be any room for “interpretation” here. Either the bird is there or it isn’t.
Now consider a slightly less clear cut situation: C claims he is a U.S. citizen; D says C is not. C points out that he was born on U.S. soil, which makes him a citizen; D says C was born in another country. Well, you say, it’s easy enough to prove C is a citizen; all he needs to do is provide his birth certificate – and that’s just what C does. But it doesn’t satisfy D, who claims that it’s a forgery. C gets the governor of the state he was born in to confirm that the birth certificate is not a forgery, but D insists that the governor is in cahoots with C and is lying. The birth certificate either is or is not a forgery, and C either is or is not a U.S. citizen. There’s a very small probability that D is correct – that C and the governor of the state he claims to have been born in are conspiring to deceive D and everyone else. But there’s no external reason to suppose this is the case; it’s much more likely that C is in fact a U.S. citizen, as he says – and as his birth certificate confirms (unless, of course, it’s a forgery).
While C and D are arguing over C’s citizenship, E and F are arguing over climate change, a much murkier subject. E says climate change is real and human-caused; F says that’s just alarmist nonsense. In the case of A’s bird, whose existence B denied, the evidence was right there in the room. B would have to convince people not to believe their own (lying?) eyes to win his side of that argument. The bird was the evidence. In the case of C’s citizenship, the birth certificate was the necessary evidence (unless, of course, it’s a forgery).
In the case of climate change it’s much more difficult to assess reality. We cannot “see” climate change, although we can see events that are consistent with what scientists say would happen if climate change is occurring. But of course any one of these events could happen in the absence of climate change – there were occasions of severe weather before the term “climate change” ever entered the lexicon. Climate change is more about expected trends than about specific events, and trends may be partially obscured by “noise.” E believes climate change is real not because he can “see” it, but because the consensus among climate scientists who are studying it is almost universal. Basically, E trusts that these scientists have integrity and really are interested in finding out the truth, whatever it may be. We can’t all be experts in everything, he reasons, so it makes sense to trust the experts, especially when the consensus among them is so overwhelming. F thinks this is all hooey – and flies in the face of the whole damn economy which is, after all, carbon-based. It would be an economic nightmare to switch from burning fossil fuels to some other energy system. We would have to be 100 percent sure about climate change to warrant doing that, and the scientists aren’t that sure. And besides, they’re probably doctoring their data to get on the “climate change band wagon” because that’s how they get (taxpayer-funded) grant money to do more research – or so the climate change-denial argument goes.
In all three of these cases – the debates between A and B, between C and D, and between E and F – there is a reality; but the ease with which this reality is confirmed differs considerably. In the case of A’s bird, we could collect enough people to view the room and confirm that it does indeed have a bird flying around. In the case of C’s U.S. citizenship, we could presumably examine the birth certificate to determine if it is a forgery; if it was determined to be valid, that should close the case – although those who are determined to disbelieve the evidence could continue to argue that the examination of the birth certificate was rigged in some way or the examiners were lying. Since we are not there ourselves to watch the examination being carried out (and even if we were, we wouldn’t necessarily know what we were watching unless we were experts too), at some point we have to trust what the experts say – or not.
The inference required to believe that C is a U.S. citizen is simple: the validity of the birth certificate implies that C is a U.S. citizen, by the laws governing this country. The case of climate change requires far more inference – and trust. The increasing concentrations of carbon dioxide and other greenhouse gases in the atmosphere over time are verifiable – scientists have measured CO2 concentrations for years. But the consequences of this increase in greenhouse gas concentrations must be inferred and the contribution by humans must be estimated. Complex models try to approximate the relationships between these atmospheric greenhouse gas concentrations and the things they directly affect, as well as the indirect impacts of the direct impacts – including possible feedback loops that might accelerate the speed with which effects occur. Not surprisingly, it’s very complicated with lots of uncertainty for skeptics to point to. Good scientists don’t try to hide the uncertainty but rather to diminish it over time as they collect more data and try to rigorously fit the pieces of the puzzle together.
Since scientists cannot simply “see” climate change, they must rely on inference that it is happening. Their inferences can be confirmed if they are borne out over time. For example, if scientists measure global mean temperature over a sufficient number of years, long-term trends, if they exist, will be detectable over the short-term fluctuations – and indeed they have been. Similarly, if climate models predict an increase in the frequency of severe storms, this is something that can be confirmed (or refuted) by the data over time. As more model predictions are borne out, the case that the models have it “basically right” becomes progressively stronger, and the uncertainty progressively lessens. That’s the process; we’re currently in the middle of that process, with varying degrees of uncertainty about different aspects of climate change predictions. But overall, the uncertainty has been decreasing, and the uncertainty about whether climate change is happening and whether it is largely driven by human activities has been reduced down to almost nothing – at least as far as the vast majority of climate scientists are concerned. And if the rest of us trust the scientists – trust their competence and their integrity – the uncertainty we harbor about these conclusions will be minimal as well.
But a substantial segment of the American public does not trust the scientists and does not believe what they are telling us about climate change – or evolution, for that matter. In addition, a substantial segment is misinformed about what the scientists actually think. A Pew poll conducted in 2010 found that between 40 and 50 percent of Americans believe in the biblical creationist story of the origins of life on earth; almost a third didn’t believe that global warming is real; over 40 percent believe the scientists don’t think the earth is getting warmer because of human activity.
As it turns out, this skepticism about science and the associated degrees to which people are misinformed, are not equally distributed across the political aisle. The same Pew poll found striking differences by political affiliation. Over half of Republicans (53%) believe there is no solid evidence of global warming, while only 14% of Democrats believe that. Conversely, 79% of Democrats answered yes to the question of whether there is solid evidence of global warming, while only 38% of Republicans answered yes. When asked whether they believe there is solid evidence that the earth is warming because of human activity, the percentages among Republicans and Democrats were 16% and 53%, respectively.
The rather alarming divergence of Republicans from science – and, more broadly, from some basically established facts – has been noted among conservative pundits. In an op ed in the New York Times on August 26, David Brooks referred to the “alternative-reality right – those who don’t believe in global warming, evolution or that Obama was born in the U.S.” In an op ed in the Washington Post on the same day, Kathleen Parker observed, “That we [in the GOP] are yet again debating evolutionary theory and Earth’s origins — and that candidates now have to declare where they stand on established science — should be a signal that we are slip-sliding toward governance by emotion rather than reason. But it’s important to understand what’s undergirding the debate. It has little to do with a given candidate’s policy and everything to do with whether he or she believes in God.”
One reason Republicans are less likely than Democrats to believe what scientists tell us about evolution and climate change is that people with different political persuasions tend to get their information from different news media these days. Republicans are much more likely to watch Fox News; Democrats are more likely to watch MSNBC or CNN, and, as has been often noted, there are clear differences in the tone in which politically charged subjects are discussed on these channels. Unfortunately, and bizarrely, both evolution and climate change are politically charged subjects. When the high profile names on Fox talk about climate change there is often an undercurrent of skepticism that is absent on the other channels. Similarly, Fox personalities have been known to insinuate that perhaps Obama isn’t actually a Christian or maybe isn’t even an American citizen.
A second likely reason for the big divergence in attitudes toward science between Republicans and Democrats, alluded to in the Parker op ed, has to do with differences in religious beliefs. All the great religions of the Abrahamic tradition (Judaism, Christianity, and Islam) describe a reality that includes supernatural components that we cannot detect with our five senses. We cannot see God; we cannot hear God (although some people have claimed they have heard God). But the vast majority of Americans believe in God.
There are different degrees of belief, however, and different conceptions of God. Many people are able to believe in God and also believe what the scientists are telling them. However, it would be more difficult to do this if your conception of God is a fundamentalist one based on the Bible, a conception that holds that God created the earth and everything on it, God hears our prayers, God cares about us. Evolution in particular represents a head on collision with the belief that God created the earth and everything on it. While climate change does not directly contradict anything the Bible says, people who lean heavily on the Bible – and I suspect many more such people are Republicans than Democrats – are far less likely to be familiar and comfortable with the entire scientific enterprise. If you believe that all knowledge comes from the Good Book, then it cannot come from the scientific method.
Notice how emotion has crept into the picture. There is the matter of trust. Unless we can verify a reality ourselves, we ultimately have to trust others who can, and trust the process by which they do this. It helps to understand that process. But ultimately, we have to trust not only the competence of those others, but their integrity as well. If the scientists and the scientific process they engage in fundamentally conflict with people’s prior method of “knowing reality” – a method they have already invested a lot of their trust in – the scientists and their process are likely to lose out.
Then there is the matter of emotional comfort. If what the scientists are telling people conflicts with a world view they already hold – and hold dearly – then to believe what the scientists say means letting go of that prior world view. Two “realities” come into conflict – one that is familiar and comfortable, and the other that the “experts” say is true, never mind if it’s upsetting. The familiar and comforting “reality” in question is the “reality” created by a particular tribe in America, a confluence of conservative religious, political, and social views that characterizes the ascendant Republican Party in modern America. It is what Kathleen Parker was referring to in her op ed. An entire network has developed to keep this “reality” alive in America.
Now imagine two people, G and H. G says there is a God (in the Abrahamic tradition); H says not that there isn’t such a God, but that there isn’t any evidence of such a God. G brings in all his friends and relatives – and there are many millions of them – all of whom agree with him. They dismiss the fact that none of them can see this God. God, they say, is a different kind of entity; we shouldn’t expect to see God. And they explain how they’ve always trusted in God and how comforting it has been to put their trust in God. And it’s not only their fellow church-goers who agree with them, they point out; all the people from whom they get their news agree with them – all the folks they watch on Fox News; none of them really believe what those elitist scientists are saying. And then there are all the people who somehow have a stake in continuing our carbon-based economy …
Of course, H has his allies too – all those scientists, for one. And then there are the atheists and agnostics, but they’re a miniscule bunch compared to the many millions of believers, a difference G doesn’t miss pointing out, as if to imply that the sheer number of believers in a reality makes that reality more likely.
In the arguments between A and B, or C and D, or E and F, we noted that there is a reality, although the ease with which this reality is confirmed differs considerably. But unlike in those arguments, there is no way to resolve the dispute between G and H using evidence in the normal sense of that word. G’s claim is unverifiable. There is no way to verify it.
“Well, let’s just agree to disagree,” says G, trying to be magnanimous. “We’ll have our reality, and you can have yours.” But this only distresses H more. “If there were no consequences to ‘whose reality’ is the ‘real reality’ then it wouldn’t matter,” he says. “But there are consequences. Whatever ‘reality’ we place our bets on, in the end there is only one reality. And that reality can be very much shaped by what we do or don’t do in light of the ‘reality’ we believe in. If you make stuff up and convince yourselves it’s true, and you act accordingly, you won’t be paying attention to actual reality, and you can do a helluva lot of damage by not paying attention and by not tending to what needs to be tended to. We all share the same reality, whether we all believe in it or not. We’re all affected by that reality – and help shape it.”
But G isn’t listening. He’s happily ensconced among his crowd of like-believers. They’re congratulating themselves on how they conducted the argument – not an argument, really, they tell themselves; a discussion. Tonight they’ll watch Fox News. And tomorrow they’ll go to church and pray. And God will hear their prayers because He loves each and every one of them. At least, that’s what they believe.
Image from: U.S. Department of Veteran Affairs: http://www.blogs.va.gov/vacareers/568/perception-versus-reality/
*Footnote (5) added Jan. 2013.
 For example, suppose we can verify empirically that x is happening; given our understanding of the relationship between x and y, we can infer that if x is happening, y is happening.
 “On Darwin’s 200th Birthday, Americans Still Divided About Evolution,” Feb. 5, 2009. Pew Research Center Publications. Available online at: http://pewresearch.org/pubs/1107/polling-evolution-creationism.
 “Little Change in Opinions about Global Warming.” October 27, 2010. Pew Center for the People & the Press. Available online at: http://people-press.org/2010/10/27/little-change-in-opinions-about-global-warming/.
 See, for example, “Americans Spending More Time Following the News Ideological News Sources: Who Watches and Why,” Pew Research Center for the People & the Press. September 12, 2010. Available online at: http://people-press.org/2010/09/12/americans-spending-more-time-following-the-news/
 A rather striking example of anti-climate change bias at Fox News is provided by Andrew Sullivan, who, on Jan. 11, 2013, posted a video of talking heads at Fox News discussing climate change in a way that was anything but “fair and balanced”: http://andrewsullivan.thedailybeast.com/2013/01/global-warming-isnt-newsy.html.
 The exact percentages vary from poll to poll and over time. However, for example, a relatively recent USA Today/Gallup poll found that 92 percent of Americans believe in God (see http://www.cnsnews.com/node/65396).
 See, for example, “Republican Base Heavily White, Conservative, Religious.” Gallup Poll, June 1, 2009, http://www.gallup.com/poll/118937/republican-base-heavily-white-conservative-religious.aspx.