PROPERTY LAW FOR THE ANTHROPOCENE ERA John G. Sprankling* Human activity has replaced nature as the principal force shaping our planet. As a result, we stand at the dawn of a new geological epoch: the Anthropocene. Fundamental changes in American law will be required to mitigate and adapt to the negative environmental impacts produced in this new era. These changes will go far beyond the traditional scope of environmental law to encompass property law and other subjects. This Article analyzes how American property law should respond to the Anthropocene challenge. It demonstrates the need to transition from a property law system based on stability to a more dynamic system that accommodates large- scale environmental disruption. It argues that we must develop a new vision of ownership in which property rights are more flexible and less categorical than in the past, and that we must implement this transition in a manner that does not violate the Takings Clause. The Article proposes four overarching principles to guide the evolution of our property law system in the coming decades. TABLE OF CONTENTS INTRODUCTION ..................................................................................................... 738 I. THE ANTHROPOCENE CHALLENGE .................................................................... 740 II. THE ENGLISH PROPERTY LAW FOUNDATION ................................................... 743 A. Static Conception of Property .................................................................... 743 B. Rigidity and Absolutism ............................................................................. 744 III. THE EVOLUTION OF AMERICAN PROPERTY LAW ............................................ 747 A. Inching Toward a More Dynamic System ................................................. 747 B. Embryonic Flexibility Themes ................................................................... 748 1. The Right to Exclude .............................................................................. 749 2. The Right to Use .................................................................................... 751 3. Time Limits ............................................................................................ 752 4. Geographic Limits .................................................................................. 753 * Distinguished Professor of Law, University of the Pacific, McGeorge School of Law. I thank Karrigan Börk, Ray Coletta, and Rachael Salcido for their valuable comments on a prior draft of this Article. 738 ARIZONA LAW REVIEW [VOL. 59:737 C. Dynamism and the Takings Clause ............................................................ 755 IV. RESHAPING AMERICAN PROPERTY LAW FOR THE ANTHROPOCENE ERA ........ 757 A. A New Vision of Ownership ...................................................................... 757 B. Four Principles for the Anthropocene Era .................................................. 758 1. Equitable Sharing Should Mitigate the Right to Exclude ....................... 759 2. More Intensive Restrictions Should Constrain the Right to Use ............ 761 3. Time Limits on Property Rights Should Be Imposed. ............................ 764 4. Geographic Limits on Property Rights Should Be More Flexible. ......... 767 C. Reinterpreting the Takings Clause for the Anthropocene Era .................... 768 CONCLUSION ........................................................................................................ 771 INTRODUCTION The historic foundation of American property law is eroding. In 2016, scientists officially acknowledged that we have entered a new geological epoch: the Anthropocene.1 This era is characterized by the reality that human activity— not nature—is the dominant force transforming the physical world.2 The magnitude and speed of this transformation are unprecedented in the history of our planet.3 As a result, we must shift from a property law system premised on stability to a more dynamic system that accommodates large-scale change. The most important challenge confronting property law today is how to adjust to the Anthropocene era in the coming decades. Our property law system evolved over centuries when the physical conditions affecting land were relatively stable. Changes produced by nature were usually minor and gradual, while human impacts on the physical world were limited and localized.4 The fee simple absolute and other property rights that emerged in this environment, first in England and later in the United States, reflected this stability. The temporal and spatial dimensions of these rights were comparatively rigid; and the substantive content of these rights tended toward absolutism, relatively free from government constraints.5 Because these property 1. See Damian Carrington, The Anthropocene Epoch: Scientists Declare Dawn of Human-Influenced Age, THE GUARDIAN (Aug. 29, 2016), https://www.theguardian.com/ environment/2016/aug/29/declare-anthropocene-epoch-experts-urge-geological-congress- human-impact-earth. 2. Anthropocene, OXFORD ENGLISH DICTIONARY (2014). 3. See JEREMY DAVIES, THE BIRTH OF THE ANTHROPOCENE 2–4 (2016); J.R. MCNEILL & PETER ENGELKE, THE GREAT ACCELERATION: AN ENVIRONMENTAL HISTORY OF THE ANTHROPOCENE SINCE 1945, at 4–6 (2014). 4. For discussions of gradual changes in the natural environment of Britain before the Anthropocene epoch, see ROBIN H. BEST, LAND USE AND LIVING SPACE 10–13 (1981) and NEIL ROBERTS, THE HOLOCENE: AN ENVIRONMENTAL HISTORY 143–53 (1989). During the Anthropocene epoch, in contrast, human activity has disrupted the environment to an unprecedented extent. See infra text accompanying notes 28–45. 5. See infra text accompanying notes 64–85. 2017] PROPERTY LAW 739 systems developed in an era of stability, they did not include mechanisms that could adjust property rights in response to major external changes.6 Today, at the dawn of the Anthropocene era, human activities have already begun to change the Earth’s climate, geology, and ecosystems. Since the middle of the twentieth century, the human impact on our planet has accelerated dramatically.7 For example, human-caused emissions of toxic substances have contaminated large regions;8 greenhouse gases are changing the climate, causing sea levels to rise;9 desertification has transformed the planet’s surface;10 and many non-human species are becoming extinct.11 Scholars conventionally view legal responses to developments like these as falling within the ambit of environmental law. But this narrow view is outdated and counterproductive. The Anthropocene era may endure for thousands of years12 and will necessitate fundamental changes in many areas of law, including property law. In this new era, when humans are reshaping the natural world in fundamental ways, our static property law system is increasingly obsolete. As the world changes, the rights of different property owners will increasingly conflict, and the respective rights of particular owners will collide with the rights of society more frequently. Our property law system must be retooled to accommodate and manage the conflicts that will arise in a rapidly changing world, but in a manner that does not violate the Takings Clause. In fact, we have already begun to shift toward a more dynamic system, at least in piecemeal fashion.13 The current challenge is to develop overarching principles that can guide the future evolution of property law. This Article explores how American property law will be transformed for the Anthropocene era. Part I examines the challenge posed by the Anthropocene— an era of extraordinary global change in terms of intensity, scale, and speed. Part II explains how stable environmental conditions contributed to England’s rigid system of absolutist property rights, without mechanisms to accommodate substantial change. Part III analyzes how American law developed doctrines that inject a degree of flexibility into the static property law system inherited from 6. See infra text accompanying notes 71–84. 7. See Colin N. Waters et al., The Anthropocene is Functionally and Stratigraphically Distinct from the Holocene, 351 SCIENCE 2622-1 (2016); DAVIES, supra note 3, at 2–4; MCNEILL & ENGELKE, supra note 3, at 4–6. 8. See MCNEILL & ENGELKE, supra note 3, at 28–29; JOHN G. SPRANKLING & GREGORY S. WEBER, THE LAW OF HAZARDOUS WASTES AND TOXIC SUBSTANCES IN A NUTSHELL 3–4, 105–07, 273–76 (2d ed. 2007); Waters et al., supra note 7, at 2622-5. 9. See INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE, CLIMATE CHANGE 2014: SYNTHESIS REPORT 42 (2015); JERRY M. MELILLO ET AL., EDS., CLIMATE CHANGE IMPACTS IN THE UNITED STATES: THE THIRD NATIONAL CLIMATE ASSESSMENT 582–83 (2014). 10. See DAVID SHERIDAN, DESERTIFICATION IN THE UNITED STATES 121 (1981). 11. See Waters et al., supra note 7, at 2622-8. 12. The previous geological epoch, the Holocene, lasted for 12,000 years. See JEDEDIAH PURDY, AFTER NATURE: A POLITICS FOR THE ANTHROPOCENE 1 (2015). 13. See infra Part III. 740 ARIZONA LAW REVIEW [VOL. 59:737 England. It also demonstrates how these doctrines can serve as the foundation for future reforms in a manner that is consistent with the Takings Clause. Finally, Part IV proposes broad principles to reshape property rights for the Anthropocene era in four key areas: (1) exclusivity; (2) use; (3) time; and (4) geography. I. THE ANTHROPOCENE CHALLENGE A new word appeared in the venerable Oxford English Dictionary in 2014: Anthropocene, defined as “[t]he era of geological time during which human activity is considered