I recently read an article containing a World War II-era poster: "When You Ride Alone You Ride With Hitler." The authors of the article asked whether governments could use similar powers of persuasion today to discourage energy consumption and thus address climate change.
Because of the significant differences between World War II and climate change, such persuasion is likely to be less successful than it was during World War II. Today, some Americans deny the very existence of climate change, others deny that climate change is related to human conduct, and still others acknowledge the existence of climate change but question the seriousness of this problem. And because climate change is a technically complex issue, citizens unpersuaded of the seriousness of man-made climate change cannot easily be persuaded otherwise. By contrast, American society stood as one against Hitler: there were a social consensus that Hitler was dangerous. As a result, individuals might have been willing to make individual sacrifices to stop Nazism.
Moreover, the Hitler poster was backed up by the law: during World War II, gasoline was rationed. Thus, a rational driver would carpool in order to avoid using up a week's ration in just a day or two. Moreover, transportation and land use systems supported the Hitler poster. Jobs were more likely to be centered in one area, a regional downtown, thus making carpooling more practical. And because suburbia was far less extensive than today, a driver's friends might live nearby, thus making easy pickups feasible. Indeed, solo driving is so much part of today's culture that (in my personal experience) environmentalism focused on individual or local government action seems to have deemphasized the issue.
By contrast, other environmental crusades seem to have received more popular support: usually those related to middle-class concerns about waste and cleanliness. For example, recycling bins are widespread even in the United States, and every few years some consumer product or other is widely vilified as wasteful; today, plastic bags and bottled water seem to be common targets of disdain.
So perhaps the poster is somewhat relevant to today: some people can be persuaded to voluntarily limit consumption in some ways- but only where such activism already fits comfortably into their lives and worldviews. So for example, any public relations campaign related to waste is likely to be somewhat successful, because the North American middle class already detests litter and obvious waste. By contrast, environmentalist attempts to persuade people to limit consumption widely viewed as integral to suburban middle-class lifestyles (such as driving) will fail. This is not to say, of course, that public policy cannot affect travel patterns- but actual changes in public policy (such as mixed-use zoning and improved public transit) are far more likely to change travel patterns than will appeals to conscience.