Thursday, December 6, 2012
Sustainability is an increasingly important concept in environmental and climate-change law. To the extent sustainability means that people should reduce their environmental impacts and shrink their carbon footprints, it seems that the increased focus on sustainability offers significant promise. But it is unclear that sustainability has that meaning; indeed, the term sustainability has become so ubiquitous and amorphous that it seems to have no common meaning. That might not matter very much when the idea of sustainability is used to promote gratuitous or individual acts of environmental stewardship. However, successful climate-change mitigation will require greenhouse gas emissions and atmospheric carbon dioxide concentrations to reach specific numeric levels. If governments replace quantifiable emissions reduction targets with ambiguous sustainability goals, this could undermine long-term efforts to reduce greenhouse gas emissions and mitigate climate change. Therefore, in the context of climate change, it is critical that governments make their sustainability programs count by measuring the benefits of their sustainability measures.
Over the past several years, a number of cities around the country have adopted climate action plans to reduce municipal greenhouse gas emissions. Many of these climate action plans focus on similar sectoral emissions-reduction strategies, such as reducing vehicle miles traveled by steering people away from single-passenger car trips; reducing waste-related emissions by encouraging composting and recycling; encouraging energy efficiency and localized renewable energy production; and encouraging other mitigation strategies such as tree planting, urban gardening, and other activities to reduce urban heat (and thereby reduce the need for air conditioning). Although these strategies may have significant potential to reduce urban greenhouse gas emissions and mitigate climate change, cities often fail to quantify the anticipated reductions the strategies will produce. Even where cities can point to emissions reductions they have achieved—for example, Portland, Oregon, has lowered its emissions to 1990 levels after pursuing elements of its climate action plan—they typically do not link emissions reductions to specific measures. Instead, cities have begun to promote the general concept of sustainability rather than develop specific strategies to meet the numeric metrics in their climate action plans.
Why should this matter? After all, if a city can show that it is simultaneously implementing a climate action plan, becoming more “sustainable,” and reducing greenhouse gas emissions, it would seem that sustainability efforts deserve praise. The problem, though, is that climate-change mitigation ultimately relies on numbers: to avoid temperature increases above 2°C, scientists estimate that global carbon dioxide concentrations must fall back to 350 parts per million (which may actually be too high), which requires quantifiable emissions reductions measured in tons of carbon dioxide equivalent. If cities are serious about mitigating climate change, they need to link their plans to quantifiable targets. Sustainability should not be exalted at the expense of governmental accountability.
That does not mean that sustainability (whatever it may mean) should not play a role in climate-change mitigation. Local climate action plans may help promote and reinforce behavioral norms necessary for societal changes that comprehensive climate-change mitigation demands. City leaders in Portland, Oregon, and New York City have tapped into the idea of sustainability to garner support for those cities’ climate plans, to encourage participation in the cities’ sectoral mitigation efforts, and to change the culture in ways that could lead to deeper emissions cuts over the longer term. The vague concept of sustainability seems to promote participation and buy-in from residents in those cities, because it provides city residents positive reinforcement as they work to improve their communities.
This concept of sustainability—that it serves to promote good will and emotional benefits—may seem weak. But research has shown in various contexts that positive reinforcement and messaging may do more to promote behavioral change than scolding and shaming do. For example, voter turnout efforts that emphasize the civic benefits and positive aspects of voting have a greater impact than efforts designed to play on voters’ fears and anger, contrary to some social scientists’ expectations. If government leaders use the concept of sustainability as a positive, upbeat strategy to enlist urban residents in climate-change mitigation efforts, this could help change societal norms. Changing norms, in turn, could allow city leaders to take more aggressive measures to achieve their quantifiable targets.
To make sustainability count in the climate change context, we should insist that cities establish quantified emissions targets and demonstrate that their sectoral strategies will achieve these targets. The concept of sustainability can help cities implement their climate action plans, but it should not displace a quantified approach.-- Melissa Powers