In my lastblog, I described five types of climate change denier. Not all of them are equally serious, and “denier” needs to be construed broadly. But all of them feed into the phenomenon of denying human-caused climate change. Here’s a recap:

• The Deceiverknows that he or she is distorting the science and does so willfully.
• The Deceived是欺骗的受害者，因此对气候变化和相关科学有错误的信念。
• The Self-Deceivedactively seeks out evidence (or “evidence”) that supports the denialist position, often because denial is part of his or her cultural identity.
• The Skepticis a sophisticate who claims the evidence doesn’t show one way or another whether human-caused climate change is occurring—but is often biasedagainstthe validity of the scientific evidence for climate change.
• The Truly Ignorantdoes not know or claim to know about climate change; this could be because of lack of interest or due to being bewildered by all the conflicting information in the popular media.

这两种类型有很多重叠的地方，但它们在原则上(通常在实践中)是不同的。

In this blog, I want to apply this taxonomy to a prominent controversy in the psychological literature about climate change denial and go some of the way to resolving it. The key idea is that elements of two different types can and often doco-exist in the same person.

On the one hand,Dan Kahanargues that increasing people’s knowledge of science—and even climate science in particular—doesnot提高对人为造成的气候变化的接受程度(这意味着同意一项调查，即有“确凿证据”证明人为造成的全球变暖;参见下面的图表)。这是令人惊讶的，因为人们会认为了解科学有助于接受它。Kahan’sexperimental strategy是衡量人们的科学素养，并检查它是否与他们对气候变化的接受程度有意义的关系。他的简短回答是，事实并非如此:更高水平的科学素养与更多人接受气候变化并不相关。Theaveragescientific literacy of deniers is no lower than the average scientific literacy of acceptors.

If it’s not scientific literacy, what does Kahan think is going on?

His answer is the Cultural Cognition Thesis. People embrace positions on climate change that support their social identities: liberal, conservative, communitarian, individualist, etc. People often knowwhatscientists say about climate change. But that doesn’t mean that they’ll express agreement with it. An oil executive, for example, might know some of the science but commit to denying climate change out of allegiance to the in-group of people in the oil industry.

Kahan’s finer-grained picture is this. Among liberals (and scientists themselves, of course), increased scientific knowledgeisassociated with greater climate change acceptance. But among conservatives, it’s the opposite: knowing more about science is associated withdecreasedclimate change acceptance. That, of course, is depressing. Knowing more science gives conservatives additional tools for denying climate change in a sophisticated-sounding way. Here are two of his key graphs. Notice that in the right-hand graph the trends go inoppositedirections for liberals and conservatives.

如果卡汉是对的，那么理智和说服(至少在这个话题上)是不能相提并论的。

On the other hand,Michael Ranney’s research seems to demonstrate the opposite of Kahan’s. Ranney and colleagues have designed interventions that teach people themechanisms全球变暖是如何发生的。And in theirexperiments，他们表明，传授这些机制可以增强人们的接受度(他们通过使用相信人类造成的气候变化正在发生的各种措施来探索接受度)。对他们来说，机械知识是关键。

What exactly is this mechanistic knowledge? It’s knowledge about the moving parts and causal structure of a system. It turns out that even most people who accept global warming don’t know the following basic information:greenhouse gasses, like CO₂还有甲烷，增加大气吸收红外线的能力;吸收红外线使大气升温;so more greenhouse gasses lead to higher temperatures as light reflects as infrared rays off the earth’s surface. (See also Ranney’s website with videos:HowGlobalWarmingWorks.org.) Ranney’s position is that when people learn those mechanisms they increase their acceptance.

If Ranney is right, reason and persuasion are allies.

How shall we resolve this controversy?

To start, Kahan’s and Ranney’s data aren’t strictly contradictory. Kahan, though he measured various aspects of climate change knowledge, didn’t assess the specific mechanistic knowledge found in Ranney’s interventions, as Ranney points out. So it could be that mechanistic learning has special properties that produce acceptance. But the deeper question is why that would be the case.

I think the answer is that humans haveboththe ability to be persuaded by reasonand参与“身份保护认知”(卡汗称之为“身份保护认知”)。对于任何与身份无关的主题，通过理性学习是默认的。随便选一个话题，比如你只是想了解堪萨斯州的草原动物;你可能会查阅相关文章，仔细思考，并得出合理的结论，从而更好地了解这些动物。没有身份保护认知。但当一个话题是文化认同的试金石时，身份保护认知机制就会发挥作用。

Still, even when a topic is covered in identity politics, the human ability to think about it rationally has not disappeared; it’s just become suppressed. So what’s needed is a tactic for jogging peopleout将他们的身份保护模式转化为他们的理性学习模式。

This is what Ranney’s experiments do. By presenting information abouthowglobal warming works that is clear and novel to most people, Ranney’s interventions spark curiosity and get them to let their identity protective guard down. The mechanistic knowledge isn’t something they’ve heard before in the ongoing culture war, so it seems less like an assault and more like straightforward information.

换句话说，自我欺骗者和真正的无知者经常共存于同一个人身上。自我欺骗者是卡汗所揭示的类型;《真正的无知》是兰尼展示的那种随时准备接受新信息的人:他会说:“哈，我不知道。”世界杯赛程2022赛程表欧洲区

Ranney, for the time being, seems to have found a way to get behind people’s identity-protective shields. That’s great. But if his methods become widespread, as I hope they do, you can be sure that The Deceivers and The Self-Deceivers will find new shields against them. So my resolution to the controversy is this: Kahan studies the identity-protective shields; Ranney looks for the cracks between them. Both, in my view, are doing the right thing by studying what they study. Saving the planet depends not just on cutting emissions; it depends also on changing the minds of people who are in denial, which depends in turn on understanding the psychology.