The neat assignment of disciplines to camps should also be rejected. The so-called “policy” disciplines clearly take normative positions. For instance, much work in climate economics aims at increasing overall welfare, and much in international relations at enhancing peace and security. These are value-laden concerns. Similarly many internal disputes in such disciplines concern ethics, rather than “what works.” For example, arguably the most important dispute within climate economics—the one that essentially drives the vastly different policy recommendations of its practitioners—is about how to value the future. One key question in that dispute is whether climate decisions should be based on a discount rate that includes a pure time preference: the observed preference of current people to get things earlier rather than later, even when this means getting less, due to impatience (rather than, say, uncertainty or risk). Another key question is whether future people should pay more for climate change if they are likely to be richer than current people. Both questions are inherently ethical, not merely technical issues in economics.
The attempt to isolate ethics is also prejudicial. No other discipline is forced to work alone. Moreover, isolationist “climate ethics” is a straw man. No philosopher argues that climate science (for example) is irrelevant to climate ethics; and the implicit suggestion that ethicists are uninterested in “what works” is untrue. Contributions from science, economics, political science and other disciplines are vital to an ethical approach to public policy, and writers on climate ethics make much use of them.
Indeed, even the idea that practical ethics could operate in complete isolation from other disciplines is bizarre. Empirical information about the world is needed if ethics is to be applicable. For instance, ethical principles (such as “if empirical situation X arises, action A is the right thing to do”) cannot be applied without information about whether the appropriate conditions (i.e., X) actually hold. This cannot come from ethics itself, but must originate elsewhere, and especially from other policy-related disciplines. The answer is not “ethics or policy,” but “both.”
One place where the prejudice against ethics becomes prominent is in the complaint that ethics lacks the “right tools” to contribute to climate policy, such as those needed to understand incentives, costs, and so on. This complaint is misleading, since climate ethics does not neglect these areas. For example, the perfect moral storm analysis is deeply concerned with incentives, and pays sustained attention to the role of game theoretic models in economics and international relations. Similarly, those advocating for particular distributive regimes, such as equal per capita emissions, typically embed them in systems of tradable permit systems (“cap-and-trade”) that come from economics, and do so partly because of the incentive effects. Indeed, arguably, climate ethics typically takes incentives more seriously than standard “policy” approaches. For instance, these typically devote no attention to the tyranny of the contemporary, and instead promulgate the traditional tragedy of the commons analysis under the (in my view dangerously naive) assumption that current institutions reliably promote the interests of future generations.