marily on his most recent study, which investigated knowledge about climate change gained through learning in both formal and informal science education environments (Leiserowitz and Smith, 2010). The study, which is ongoing, is based on interviews conducted with a representative sample of 2,030 adults ages 18 and older between June 25 and July 22, 2010. According to some preliminary results that Leiserowitz described, knowledge about climate change can be divided into several general and overlapping categories:
• knowledge about how the climate system works;
• specific knowledge about the causes, consequences, and potential solutions to global warming;
• contextual knowledge placing human-caused global warming in historical and geographic perspective; and
• practical knowledge that enables individual and collective action.
The study included a series of questions asking respondents to rate their level of knowledge in terms of each of these dimensions. Other questions addressed the respondents’ desire for more information, trust in different information sources, perceptions of the risks of climate change, policy preferences, and behaviors.
In previous research, Leiserowitz (Maibach, Roser-Renouf, and Leiserowitz, 2009) identified six unique segments of the American public, referred to as Global Warming’s Six Americas, each of which responds to information about climate change in distinct ways. The Six Americas represent a broad spectrum of responses to climate change, from active engagement to complete dismissal. They are categorized as follows:
1. The “Alarmed” represent the most engaged public; they believe that global warming is occurring, that it is human-caused, and that it is a serious threat.
2. The “Concerned” believe that global warming is a serious but distant threat and are less personally engaged with the issue.
3. The “Cautious” are less certain that global warming is happening or that it is human induced and do not have a sense of urgency about it.
4. The “Disengaged” don’t know or think about the issue.
5. The “Doubtful” are split between believing and disbelieving in global warming, but those who accept global warming are most likely to believe that it is due to natural causes and does not pose a threat to people.
6. The “Dismissive” are actively engaged with the issue but do not believe global warming is happening, represents a threat, or warrants a national response.