abstract. “Net zero” has rapidly become the new organizing paradigm of climate change law. In the past few years, thousands of countries, companies, states, and cities have developed pledges that promise by a set date—typically around 2050—that any carbon they emit will be counterbalanced by capturing an equal amount of carbon out of the atmosphere. Collectively, these pledges now cover more than 91% of the global economy.

This widespread adoption of scientifically aligned climate policy appears on its surface like a cause for celebration. However, concerns are mounting. To date, critiques of net zero have centered on what this Feature terms “accounting” risks: that is, risks that pledges in action will fail to live up to pledges on paper. This Feature argues that there are two broader normative and political risks with net zero that are underdiagnosed but may prove more intractable. First, the net-zero framework is agnostic regarding the manner in which to neutralize atmospheric emissions, leaving each participating entity—including both governments and corporations—to determine its own preferred strategy. But decisions around how to reach net-zero emissions are contested, impactful, and often politically explosive. As net zero has proliferated as a framing paradigm, there has been a marked shift in the climate change policy conversation towards recognizing climate as imbricated with racial and economic justice. These considerations are ignored in the net-zero framing, with its emphasis on pristine carbon balance sheets. The second risk this Feature identifies is the “collective-achievement challenge”: if the world continues to pursue an atomized approach to net zero, it is likely that entities will overrely on certain cost-effective strategies—like tree planting—at scales that cannot be collectively achieved, at least not without substantial collateral social consequences. Disjunctive efforts toward net zero thus threaten to undermine the legal, political, and physical foundations of global decarbonization efforts. Understanding these risks counsels for restructuring the private sector’s role away from individualized net-zero targets toward a “reduce and support” approach that would better collectivize and rationalize net-zero policy. For public pledges, these risks counsel for more attention to net zero’s administering institutions and governance structures to foster more democratic, holistic decision-making about the shape and content of our decarbonized future.

author. Presidential Distinguished Professor of Law & Energy Policy, University of Pennsylvania Carey Law School and the Kleinman Center for Energy Policy. Thanks to Cary Coglianese, Sharon Jacobs, Douglas Kysar, Albert Lin, Joshua Macey, Nina Mendelson, Jonas Monast, James Salzman, and participants in the University of Michigan Law School’s Legal Theory Workshop, the Southeastern Environmental Law Scholars’ Workshop, the Loyola-Chicago Starved Rock Environmental Law Scholars’ Workshop, the University of Colorado Boulder Junior Energy Law Scholars’ Workshop, and the Advanced Regulation Seminar at the University of Pennsylvania Carey School of Law for valuable comments on various drafts. Thanks to Matt Stevens for truly outstanding research assistance.

Introduction

“The pursuit of a net-zero target is perhaps the most ambitious collective undertaking in human history.”1

Almost all of a sudden, “net zero” has become the organizing paradigm of climate change law. In 2015, signatories to the Paris Climate Agreement committed to “achieve a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases (GHGs) in the second half of this century.”2 Scientists widely agree that this global balancing effort will be critical for keeping planetary warming to noncatastrophic levels.3 In the five years since the Paris Agreement, countries, states, cities, and companies have coalesced around a project of creating their own net-zero commitments. In these commitments, entities pledge to ensure by a set date—typically around 2050—that any remaining carbon they emit is counterbalanced by capturing an equal amount of carbon out of the atmosphere.4 As of September 2022, net-zero commitments covered an impressive 91% of the global economy (as measured by gross domestic product (GDP)), up from only 16% as recently as 2019.5

It is stunning how quickly the climate change field—which has been rife with epistemological and methodological disagreement for decades—has accepted net zero as the central goal of climate policy and the key metric for academic analysis.6 But scientists’ prescription of a global emissions-netting imperative is critically different from the net-zero project described in this Feature, which translates the collective scientific imperative into disjunctive, atomized pledges.7 To be sure, these pledges represent substantial progress in climate change discourse with their clear framing, certain dates, and obviously widespread appeal. Yet scientific, political, and social concerns are mounting regarding the risks of framing our response to the climate crisis through a goal of net zero.8 To date, critiques have centered on what this Feature terms “accounting” risks: that is, risks that pledges in action will fail to live up to pledges on paper, either because countries and companies are disingenuous in their commitments or because technological innovations fail to deliver reliable, long-term carbon-removal solutions at the scale and scope that these entities hope.9

Accounting risks are real and concerning, but they are not net zero’s biggest challenge. This Feature diagnoses two deeper and broader normative risks with the net-zero project. The first, which it terms the “neutrality mirage,” stems from the putative neutrality of the net-zero framework. Orienting climate policy around the overarching goal of neutralizing atmospheric emissions suggests indifference about the best pathway to net zero. But in reality, the details of how to net emissions are contested, consequential, and often politically explosive.10 Indeed, at the same time net zero has proliferated as a framing device, policy conversations have shifted toward recognizing climate change as imbricated with racial and economic justice.11 The net-zero paradigm, with its emphasis on pristine carbon balance sheets, largely ignores these social dimensions, which are critical for political legitimacy and durability.12 By linking this challenge to analogous critiques of cost-benefit analysis in legal theory, this Feature illuminates the risks of a climate program that intentionally sidelines democratic and distributive considerations.13

The second risk this Feature identifies is what it terms the “collective-achievement challenge.” Net-zero pledges, as currently structured, have a distinctly libertarian valence: each entity (of various scales—sometimes down to the individual14) voluntarily offers to zero out their own universe of carbon emissions in the way they see fit.15 But the emissions-netting imperative is global: to avoid planetary catastrophe, the world collectively must balance all unavoidable emissions with negative emissions. To achieve this task, climate models suggest that every feasible emission cut that can be achieved anywhere must be pursued, even as the world also attempts to recapture carbon from the atmosphere for long-term storage.16 The libertarian approach to net zero fails to reflect this scientific reality. Instead, it allows each pledging entity to plan for itself how it will neutralize its emissions—a strategy which may ultimately result in irreconcilable plans that exacerbate other development challenges while underachieving on a global scale.

By way of illustration, imagine that forty developed countries each plan to invest substantially in developing-country reforestation as a method of counterbalancing emissions that prove costly to cut from their domestic economies. At the same time, those developing countries plan domestic reforestation initiatives to neutralize their own emissions, and hundreds of major corporations plan to rely on carbon-offset credits generated from reforestation projects to achieve their net-zero targets. On the whole, there simply may not be enough opportunities for reforestation initiatives to serve all these separate entities. This risk is not speculative: Shell Oil is already pushing a vision of how to limit warming that relies on reforesting an area the size of Brazil.17 Although plausible in theory, such strategies face political and biophysical limits and are likely to have unintended collateral consequences: for example, overreliance on reforestation may contribute to food insecurity or plantation-style development at the expense of community livelihoods.18

For these reasons, disjunctive efforts toward net zero pose real risks for the critical global imperative of atmospheric neutralization. This risk is particularly acute given the legal structure of the Paris Agreement, which is premised upon country-driven pledges whose ambition is expected to strengthen over time as global trust is established. Under this legal order, a private marketplace might displace country-centered ambition, ultimately proving counterproductive to sustained global progress.19

Understanding these deeper risks with the net-zero framework does not wholly undermine its potential, but points to two critical lessons about how to structure it going forward.20 The first lesson regards the private role in achieving net zero. Contrary to the predominant current approach of the United Nations and various other net-zero champions,21 corporations should not be encouraged to develop, submit, and pursue net-zero pledges. The immense normative and political stakes of determining how to net emissions in a coordinated, democratic, and equitable fashion render this task ill suited for atomized corporate actors. Though forceful, this conclusion is not an indictment of corporate action on climate change. To the contrary, this Feature offers a nuanced gloss on private net-zero governance, encouraging corporate standard setting with respect to emissions reductions but suggesting alternative means of engaging corporate actors in carbon removal.22

The second lesson regards public actors, most notably countries and subjurisdictions such as U.S. states. These democratic actors appropriately shoulder the normative burden of deciding how to structure their net-zero projects to help achieve the global emissions-netting imperative. This fact underscores what should be an obvious conclusion: institutional design is central to the project of net zero. When a jurisdiction sets the goal of neutralizing the emissions of an entire economy, the program administrator will have (at least) thousands of choices to make regarding how to achieve that ultimate balance, both temporally and substantively—choices with wide societal implications.23 Yet there has been limited attention paid to decisions regarding who should hold this authority and under what oversight mechanisms. This Feature establishes an agenda for exploring institutional design and structural guardrails that could offer more democratic legitimacy and political durability to the net-zero project.

This Feature’s analysis moves beyond the writing to date on net zero’s accounting risks to situate the framework more broadly within the political economy and legal structure of climate change policy. In the process, it puts into conversation the legal literatures on climate change law, climate justice, cost-benefit analysis, private environmental governance, and corporate social responsibility. It also incorporates emerging social-science research into the often overly technocratic conversation on designing climate regulation.24 This research is critical for clarifying how and why climate change mitigation is a normative project with widely reverberating consequences.

Understanding the implications of the net-zero turn in climate policy is a high-stakes, pressing endeavor. Countries, states, and corporations are beginning to shift from drafting and wordsmithing broad pledges and policies to determining how to implement them. Netting global emissions in politically and ecologically sustainable ways is likely to be a central challenge of global and domestic climate policy for the coming decades—and may well prove determinative of how many degrees of warming the planet will endure. This effort will require thoughtful and creative policy design, advocacy, and, at times, litigation.25 This Feature’s contention is that careful, big-picture thinking about the shape of the net-zero project now—among academics, policymakers, and advocates alike—might be the difference between net zero as a constructive organizing principle, and net zero as a manipulable, destabilizing distraction.

This Feature proceeds in five Parts. Part I addresses the origins, appeal, and structure of net zero. Part II outlines the three accounting critiques often leveled at net-zero pledges. Part III develops the deeper normative critique of net zero’s putative neutrality previewed above, while Part IV focuses on the collective-achievement challenge. Finally, Part V highlights the central lessons this analysis offers for climate governance, arguing for a cabined role for private actors and for centering the importance of public institutional design.