community—and not powerless members of an unmanageably large group—can empower them to act. This can help make a long-drawn, global phenomenon personally relevant and immediately newsworthy and accentuate the local and individual ownership of the solutions local. Third, greenwash from business and government—the gap between agreeing publicly on the reality of climate change while doing nothing about it—needs to be limited to avoid public confusion and public backlash.

A key and controversial question is whether detailed public understanding of highly complex issues such as global warming is actually feasible, and even necessary, for effective policymaking. The answer is no, or at least not always. Much policymaking is based on technicalities fully ignored by the public. Few people understand the intricacies of trade policies affecting the price of the food they buy and eat, or produce and sell. Where buy-in is necessary, it is often encouraged through other means.

Yet discounting information and public awareness as unnecessary would be a mistake. Recent work has highlighted that information is key for the public to back costly measures. The benefits of providing more accurate information about people’s consumption decisions—say, through carbon labeling and smart meters—have long been proven. A US-based survey found that one of the main factors responsible for the public’s negative perceptions of cap and trade schemes is not fear of additional costs but rather limited knowledge of its effectiveness, reducing public trust in them.<sup>29</sup> Similarly, opposition to environmental taxes seems to decrease once the public fully understands that they are a way not simply to raise money, but to change behavior and reduce a negative externality.<sup>30</sup> _Institutional measures._ Beyond communication, a key question for climate policy is to design interventions that take into account psychological and social constraints to positive action. The design of effective adaptation interventions should include institutional measures reducing the transaction costs for individuals in making decisions while enhancing the ownership of the information available. This would require adaption strategies to be informed by communities’ own perceptions of risk, vulnerability, and capacity. The institutionalization of participatory self-assessments for national and local disaster preparedness, adaptation planning, and mitigation targets can be useful in this.

Measures to limit individuals’ tendency to discount the future are another area of action. Although discounting the future is an innate and internal mental quality, it varies in accord with social characteristics and external stimuli. Evidence from Peru shows higher discounting associated with higher incentives to deforest and lower incentives to invest in reforestation. Farmers with limited access to credit and insurance and weak property rights security will have higher discount rates.<sup>31</sup> Institutional reforms aimed at improving credit access and property rights can affect inner behavioral drivers of discounting.

> 29 Krosnick 2008. 30 Kallbekken, Kroll, and Cherry 2007. 31 Swallow and others 2007.

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