opinions about the future of agriculture then leads to the questions of how to prioritize the sustainability goal(s), what are the appropriate tradeoffs to be made, and, importantly, who gets to decide. That is, whose values matter, who benefits, and who bears the costs?
Currently in the United States, and unlike the European Union (EU) (Dobbs, 2008), no comprehensive policies promote broadly and coherently defined sustainable agricultural trajectories. Instead, sustainability goals tend to be identified and addressed separately across a mix of settings, including farm commodity programs, farm and nonfarm environmental regulation, agricultural research and technology development, land use policies, grassroots activism, and public and private efforts to develop markets that reflect emerging consumer preferences for food products raised under certain production conditions (for example, organic, natural, fair trade, or cruelty-free livestock practices). Sometimes other policies work at cross purposes with those policies pursuing sustainability goals. For example, policies to mandate the use of biofuels for the fueling of automobiles could result in increased food prices as some commodity crops are used for fuel production (Collins, 2008; Tokgoz et al., 2008), or they could encourage extension of agriculture into previously nonfarmed lands with attendant losses of important habitat or unwanted contributions to climate change (Searchinger et al., 2008).
From the preceding discussion, it is apparent that the sustainability of agriculture is not simply a question of science. Decisions about selecting among various alternative futures for agriculture and their attendant environmental, economic, and social goals emerge from an articulation of social aspirations, which falls within the realm of politics. It is through deliberative, democratic processes that the expression, discovery, transformation, and creation of social beliefs and policy preferences can occur.
Because societal sustainability goals do not emerge from science (although they can be informed by scientific knowledge), there are implications for what science can and cannot tell us. For example, science cannot with validity tell us what ought to be (for example, provide societal objectives or decide what course of action should be taken), but it can provide an analysis of alternatives and options and make predictions about potential outcomes from the use of different approaches. In essence, a major role for scientists is to serve as honest brokers in terms of involvement in policy formulation—adding knowledge to the “what is,” “what if,” and “if, then” types of questions, but leaving the “what ought to be” questions to nonscientific forums (NRC, 1996; Pielke, 2007). Thus, science is needed to help identify and clarify issues, and to seek to expand the choices available for whoever is making decisions about management of agricultural systems, be they policy makers, commodity organizations, farmer groups, or individual farmers. Science can also supply the knowledge necessary for the development of new agricultural technology (for example, technology for controlling water pollution), but scientists can only validly advocate the adoption of such technology when there is general agreement on the overall social objective to be accomplished (for example, water quality protection). The more contentious the debate over desirable objectives and the more uncertain the related science as to causes and effects, then the more important it is for scientists to adopt an “honest broker” strategy.3 It is