Coastal cities worldwide are squeezed by two opposing forces: urban sprawl and the rising sea. This struggle is intensely visible in the flatlands of South Florida, where burgeoning neighborhoods routinely flood and saltwater inundation damages the estuaries that protect communities from the worst of our climate crisis.
Massive resources are being put into environmental restoration projects there, and development is subject to many layers of approvals. Yet in 2022 the Miami-Dade County Commissioners voted to expand a legal boundary that contains sprawl to allow a 400-acre warehouse project. They are failing to see the value of this land in the greater ecosystem: pave over it, and you'll cut off waterways that sustain a critical buffer against flooding and erosion.
Wetlands, coastal plains, sand dunes, forests, and many other permeable surfaces do cheaply (or even for free) what engineered levees, seawalls and pumps do at a cost of billions of dollars. They protect the land around them from storm surge, flooding rains, erosion and pollution. They are vital infrastructure that makes us more resilient against climate change, and the cost of destroying them or weakening their ability to function must be factored into the decisions we make to build and grow.
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To do so, the economic incentives to develop any natural landscape should be weighed against the protective economic value that land already provides. Economists call this an “avoided damage” valuation. Local planning boards might consider the value of a sand dune, oyster reef or swamp in flood protection versus the expense of replacing it with a seawall and water pump system. How do these “ecosystem services” fare against the cost of, say, 30 years of emergency operations, utility failures and repeated rebuilding? Maintaining and restoring natural infrastructure to support healthy functioning saves money, time and lives.
The concept of “natural capital,” or the idea that ecosystem services should be valued in a similar manner as any form of wealth, dates back to the 1970s. Markets have always valued timber as a commodity, for example, but not the services that came along with producing it, such as soil maintenance, carbon storage, erosion control and nutrient cycling. We didn't need a market for resources that industrialists saw as abundant and endlessly renewable. This exploitative assumption turned out to be very wrong. Failing to measure the benefits of ecosystem services in policy and management decisions is a major reason many of those ecosystems disappeared. In one of many recent corrections to earlier misunderstandings of the value of nature, a 2021 World Bank report said that natural capital should redefine wealth.
Climate change makes the undervaluation of ecosystem services more dangerous. Wetlands that mitigate flooding in a community during rare deluges will have far more economic value in 2050 when damaging storms arrive more frequently. The value of a preserved forest is unfathomably large when it prevents new pathogens from emerging and spinning out into a pandemic. Clearly, monetary valuation of nature is tricky to estimate and has practical limits. It's also highly site-specific, with the protective value depending on the surrounding density of people, industries and infrastructure. It would be difficult to create a template that would help all types of municipalities crunch the math on natural assets.
It also seems crass to place a dollar amount on ecosystems that we'd rather view as priceless, existing for their own sake and valuable to humans in ways that transcend capitalism. This preciousness is ethically sound. But developers have long conflated pricelessness with worthlessness, allowing them to profit without paying for the consequences of destroying the environment. It's impossible to avoid difficult trade-offs between development and conservation—we cannot ignore the affordable housing crisis in the U.S., for example. The case for preserving nature as infrastructure, however, aligns with what many urban planners are calling for as solutions: moving away from single-family zoning restrictions to allow for multifamily and mixed-use construction and communal spaces that reduce car dependency. Basically, less sprawl.
Economic value is never the only reason nature is worth preserving; it is simply a powerful, underused tool to help us make decisions about how to live more sustainably in a climate-changed world. If policy makers considered natural infrastructure in the language of economics, they might recognize just how deeply we rely on it.