The Case for Ecological Realism

In an article for World Politics Review, CFR James H. Binger Senior Fellow in Global Governance and Director of the International Institutions and Global Governance Program Stewart M. Patrick argues it is time to embrace a new approach to world politics that deals with what may be humanity’s gravest existential challenge: preserving the integrity and resilience of the biosphere.

The global environmental crisis, encompassing runaway climate change, collapsing biodiversity and the slow death of the world’s oceans, has exposed the limitations of traditional political realism as a guide to statecraft in the 21st century. The time has come for the nations of the world to embrace a new approach to world politics that treats the preservation of the biosphere as a core national interest and a central objective of national security policy. Call this new mindset ecological realism.

Political realism, which has long dominated the teaching and practice of foreign policy, including in the United States, is a venerable intellectual tradition with roots in the writings of Thucydides, Machiavelli, Hobbes and Rousseau. As formalized by mid-20th-century thinkers like Reinhold Niebuhr and Hans Morgenthau, and later by Kenneth Waltz and Robert Gilpin, among others, it depicts the international system as an inherently anarchic realm populated by independent states recognizing no superior authority. Its outlook is tragic. Inhabiting a cutthroat, self-help system in which the possibility of war is ever-present, states must remain vigilant, seeking to amass and maintain military capabilities to deter and defeat potential adversaries.

These competitive dynamics create a well-known security dilemma, whereby one state’s quest for military dominance—and its technological and economic foundations—generates anxiety among other states, which double down on their own efforts. International institutions may temporarily dampen these conflict dynamics, political realists allow, but any international cooperation is inherently fragile and transitory, because what preoccupies states is not whether they reap absolute gains from collective action, but whether they benefit more relative to others. Political realists acknowledge the utility of alliances, but they are skeptical that solidarity based on shared purposes or identities can long endure in the absence of a common adversary. International law, likewise, carries weight only when it reflects the interests of the powerful.

The tradition of political realism owes its staying power to its compelling simplicity. It reduces international relations to two variables, namely human nature—the desire to dominate—and international anarchy—the absence of world government. These two factors make conflict inevitable and cooperation difficult. Political realism is most effective at explaining how states respond to perceived threats from other states. It loses its way, however, in confronting what Gregory F. Treverton and his colleagues term “threats without a threatener,” namely dangers arising not from geopolitical rivalry or malicious intent, but from human interactions with the environment, as with climate change or pandemic disease. Indeed, political realism provides little guidance on how to think about, much less surmount, what may be humanity’s gravest existential challenge: preserving the integrity and resilience of the biosphere, upon which the survival of our species, and indeed of all life on Earth, depends.

Political realism’s blind spot is its presumption that humanity’s relationship with the natural world exists in a steady state. The arrival of the Anthropocene—a new geologic era in which humans have suddenly become the most important force shaping the living planet—refutes that assumption. It also exposes the yawning chasm between our fragmented international system, composed of nearly 200 sovereign entities, and the integrated Earth system, a bio-geophysical unity that obeys no national boundaries.

Traditional political realism cannot bridge this gap. To address the global environmental crisis, the United States and other countries will need to embrace ecological realism. The point of departure for this perspective is recognition that the entire human endeavor depends on whether our planet remains conducive to life as we have known it. Ecological realism does not deny the concept of the national interest, but it broadens it well beyond the short-term pursuit of military, economic and technological power, to include a longer-term imperative: sustaining Earth’s life-support systems. It likewise enlarges the concept of national security to encompass what might be termed “natural” security, or the ecological preconditions of human survival and prosperity.

Ecological realism bases its claims not on controversial and contested theories of human nature and international anarchy, but on science—namely, accumulating empirical evidence of the grievous damage we are doing to the biosphere.

The historic 2015 Paris Agreement on climate change, which has been signed by 194 governments and the European Union, commits its signatories to limit the rise in average global temperatures by 2050 to no more than 2°C, and ideally 1.5° C, above preindustrial levels. Most climate scientists believe that humanity will far exceed these targets. Although greenhouse gas emissions have temporarily dipped during the COVID-19 pandemic, they are poised to surge during the eventual economic recovery, particularly as many countries have failed to formulate and fund “green” rescue packages. Without prompt and drastic emissions reductions, there seems to be little hope of keeping warming below 3°C.

The impact of rising temperatures on humans and many other organisms will be catastrophic. We face a future of searing heat waves, violent storms, cataclysmic wildfires, melting ice caps and rising sea levels. These trends will endanger water and food security, encourage mass human migration and destabilize already fragile states. Oceans will warm and acidify, endangering the phytoplankton that today absorbs one half of all anthropogenic carbon and serves as the foundation for complex marine food webs. Ninety percent of coral reefs, often referred to as the “rainforests of the sea,” could disappear by 2050.

As the planet warms, ecosystems will become further degraded and species will disappear at an accelerated pace. The bloodless phrase “biodiversity loss” fails to capture the magnitude of this looming calamity and the price humanity will pay. We often treat nature as something that is simply nice to have, as if we could do or live without it. The reality is that we depend on a healthy biosphere to provide us with innumerable, invaluable “ecosystem services,” from the rainforests that generate oxygen for us to breathe to the bees that pollinate our crops, the habitats that filter toxins from our water—and, closest to home, the billions of microbes that populate our gut biome and permit us to live. As the famed evolutionary biologist E. O. Wilson has written, “Biodiversity as a whole forms a shield protecting each of the species that compose it, ourselves included.”

Surviving the Anthropocene will require reducing humanity’s overall ecological footprint, by abandoning unsustainable patterns of production and consumption that run down Earth’s natural capital assets. This new path will also necessitate unprecedented forms of international cooperation and new structures of global environmental governance to reduce humanity’s ravenous appetite for natural resources and arrest climate change, biodiversity loss and ocean degradation.

Traditional political realism suggests that these goals will prove illusory, because states are loath to relinquish freedom of action and national sovereignty, and are tempted to shirk their obligations while free riding on others’ efforts. Ecological realism is more sanguine about the prospects for cooperation, because it recognizes that all humans, regardless of what country they inhabit, have a shared self-interest in choosing survival over extinction.