I very much appreciate the thoughtful commentary of Professors J.B. Ruhl and Nathan Sayre on my article. They are engaged in tremendously interesting thinking on questions of environmental scale and governance, and I find their comments insightful. I agree with both of them that this article opens further research questions about what diagonals are, how they have been constituted over time, the ways in which law and political economy interact through them, and how they might fit into panarchical conceptions of governance. More broadly, their comments speak to the value of bringing law and geography together to address complex environmental problems.
My exploration of diagonals in the context of climate litigation raises questions for me about the benefits and limitations of such cross-cutting approaches. As I, like Ruhl and Jim Salzmann, reflect on the messiness of problems like climate change, I agree with them that our approaches need to engage the panarchical nature of the formal and informal interactions taking place. However, I also struggle with the scalar stickiness of law, which is subdivided into relatively fixed levels of governance. When we try to craft governance structures that encompass the messiness of climate change, what I would term fully integrated diagonal approaches, their complexity becomes daunting. In a companion piece to this one, tentatively entitled Diagonal Climate Regulation: Implications for the Obama administration, which I hope to have in full draft by the end of the summer, I am thus considering the vectors that comprise diagonal interactions and the possibilities for crafting integrative approaches through combinations of partial diagonal regulation. Specifically, I am considering regulatory scale (small scale v. large scale), axis (vertical v. horizontal), hierarchy (top-down v. bottom-up), and cooperativeness (cooperative v. conflictual). I think that a study of these vectors and how regulatory approaches at different points along them might be combined in the context of the Obama administration’s efforts may help to get at the complexity Ruhl rightly highlights.
Moreover, I agree with Sayre that history and political economy are key elements for understanding how effective diagonal regulatory approaches might be developed. I had the pleasure of participating this spring in a Washington University Journal of Law & Policy symposium organized by Dan Mandelker and Dan Tarlock on New Directions in Environmental Law. The symposium explored how U.S. environmental regulation should develop through paired presentations on the history of major statutes and possibilities for the future. One thing that struck me throughout the dialogue was the complex interplay of science, scale, and law taking place in each of these substantive contexts. I think that we can learn from the experiments in horizontal, vertical, and diagonal governance that these statutes create—both in the provisions themselves and in the formal and informal interactions regarding their creation, interpretation, and implementation—as we consider what the next generation of environmental governance should be. For example, the Clean Air Act has a number of provisions that create diagonal interactions, such as the waiver provision discussed in depth in Is Climate Change “International”?: Litigation’s Diagonal Regulatory Role. An engagement of the rich federalism literature regarding these statutes through the lens of geography’s nuanced exploration of scale provides many possibilities for future inquiry.
These historical questions are made more difficult by the way in which time interacts with the problem of climate change. Current levels of greenhouse gases in the atmosphere result from emissions allowed under past regulatory regimes, and future levels will be influenced by past, present, and future laws. As noted in Is Climate Change “International”?, different parts of the climate system respond at varying paces; for example, the ocean and atmosphere do not evolve at the same rate. Similarly, impacts and adaptation needs vary simultaneously across time and space, which create policy and justice dilemmas. To make things even more complex, scientific uncertainty is greater at smaller spatial and temporal scales. Efforts to craft diagonal approaches will need to be grounded in the historical contests and their resolution that Sayre describes, as well as these spatio-temporal interactions.
I similarly concur with Sayre’s assessment of the critical role that the scales of the political economy play. In my earlier work on climate change litigation, particularly The Geography of Climate Change Litigation: Implications for Transnational Regulatory Governance, I explored these cases as multiactor, multiscalar, multibranch interactions which center around state-corporate regulatory dynamics regarding climate change. These suits generally focus either on whether or not government should be regulating major corporate emitters or directly on the auto and power plant industries. More broadly, the complex legal, political, and economic scales of governmental and nongovernmental entities, as Sayre notes, influence the possibilities for effective diagonal regulatory strategies. Some local governments, such as San Bernardino County for example, are larger than many states and even smaller nations, and the most significant U.S. state emitters would rank among the countries with the greatest emissions if they were so categorized. Major corporate emitters are simultaneously local, state, national, and transnational. These complex identity issues blurs a description of a diagonal as small or large scale, top down or bottom up, and vertical or horizontal.
The nuances that the commentaries by Ruhl and Sayre highlight thus reinforce the role that law and geography can play in crafting more effective regulatory strategies for complex problems like climate change. Geography’s engagement of place, space, and scale can add depth to legal analysis, and law’s understanding of regulatory intricacy can do the same for geographic analysis. An exploration of diagonal regulatory strategies in this context forms one piece of that larger project.