This article provides a concise overview of methods for analyzing policy choices that have been used in the study of long-term environmental challenges. We open with an overview of the broad classes of methods used for long-term policy analysis, and subsequent sections will describe in depth three particular methods. They are: statistical models, such as employed in the debate on the environmental Kuznets curve, which infer past patterns from data and project them into the future; robust decision-making, a decision analytic framework that supports choices under deep uncertainty, and relates near-term policy interventions to different clusters of long-term environmental futures; and adaptive control and agent-based modeling, which provide an approach to simulation modeling that focuses on cooperation and conflict among multiple actors and their choice of strategies. While all three approaches can be used for various applications, this article focuses on the challenge of a potential transition to a low-carbon future to illustrate the strengths, weaknesses, and synergies among the respective methods. In the final section, we offer guidance for choosing among methods.

Considering the long-term is not new, yet we seem to be overwhelmed by the long-term nature of many of our environmental policy problems. Following a definition of long-term policy problems, this editorial introduces the contributions to this special issue of Global Environmental Politics and outlines three major challenges for future research, including the time inconsistency problem, the effect of democratic and decentralized governance on problem-solving, as well as institutional designs to prevent or recover from unwanted long-term policy outcomes.

As a quintessential long-term policy problem, climate change poses two major challenges. The first is to develop, under considerable uncertainty, a plan for allocating resources over time to achieve an effective policy response. The second is to implement this plan, once arrived at, consistently over time. We consider the second of these two challenges, arguing that it consists of three interrelated, commitment problems—the time inconsistency problem, the domestic politics problem, and the anarchy problem. We discuss each of these commitment problems in some detail, explore how they relate to climate policy, and suggest institutional designs that may help limit their adverse impact. While each of these commitment problems is difficult to tackle on its own, climate change requires us to cope with all of them at once. This is likely one major reason why we have so far made only modest headway on this vital issue.

Arild Underdal's work on the Law of the Least Ambitious Program (LLAP) is a significant contribution to our understanding of the logic of international collaboration. The LLAP, however, applies only under particular conditions. After comparing the law to the joint decision trap and the veto player concept, we discuss four observations that tend to limit the law's domain. First, while the LLAP is intended to apply to decision-making under unanimity, in a number of international bodies decisions are made by some kind of majority voting. Second, the LLAP assumes that the alternative to collective agreement is individual decision-making, yet in practice the relevant alternative (the “reversion rule”) is often the continuation of some pre-existing collaborative arrangement. Third, whereas the LLAP assumes that the unanimity rule invariably favors the least ambitious program, there are interesting cases where this assumption does not hold. Finally, the LLAP does not take into account that the outcome of international decision-making not only depends on the decision rule and the reversion rule, but also on the voting sequence.

In international regimes research, one of the most important questions is how effective regimes are in delivering what they were established and designed to achieve. Perhaps the most explicit and rigorous formula for measuring regime effectiveness is the so-called Oslo-Potsdam solution. This formula has recently been criticized by Oran Young, himself one of the founding fathers of regime analysis. The present article reviews and responds to his critique and provides several extensions of the Oslo-Potsdam solution. Our response may be summarized in three points. First, we recognize that difficult problems remain unsolved. Second, we argue that for some of the most profound problems there is no escape; we need to engage in counterfactual reasoning, and we need some notion of the “best” solution achievable (such as the “collective optimum”). Finally, we would welcome efforts to further develop and refine the Oslo-Potsdam formula as well as alternative approaches.