Natural capital is the world’s stock of natural assets: land, water, air, minerals, forests, wetlands, and all living things. Just as a business tracks its financial capital or a country measures its infrastructure, natural capital represents the wealth held in nature that makes economic activity and human life possible. A landmark study published in Nature estimated the value of global ecosystem services at an average of $33 trillion per year, nearly double the global gross national product at the time.
How Natural Capital Works
Think of natural capital as nature’s balance sheet. The “stock” is everything from a forest to a coral reef to an underground oil deposit. The “services” are what those stocks produce: clean air, drinkable water, pollination of crops, climate regulation, flood control, and raw materials for manufacturing. A wetland filters pollutants from water. A mangrove forest absorbs storm surges. Bees pollinate roughly a third of the food we eat. These aren’t abstract ecological concepts. They are economic inputs with real, measurable value.
What makes natural capital distinct from other forms of wealth is that much of it is governed by biological processes humans can’t fully replicate. Because natural capital often consists of populations of living organisms and interconnected ecosystems, its quantity and quality change over time according to ecological dynamics. Research on the substitutability of natural and human-derived capital (things like machinery, infrastructure, and management practices) has found that even when technology can replicate the short-term function of a natural system, it doesn’t necessarily work as a viable long-term substitute. A water treatment plant can do what a wetland does, but it requires energy, maintenance, and eventual replacement. The wetland sustains itself.
Renewable vs. Non-Renewable Natural Capital
Natural capital splits into two broad categories based on whether it can regenerate within a human lifetime.
- Renewable natural capital includes forests, fisheries, freshwater, soil, wildlife, and sources of energy like sunlight and wind. These resources can regrow, replenish, or cycle indefinitely when managed sustainably. Trees are a straightforward example: harvest them at a rate slower than they grow, and the stock renews itself. Nutrients, the chemicals that living things need to survive, are also renewable because they cycle through ecosystems continuously.
- Non-renewable natural capital includes fossil fuels (coal, oil, natural gas) and minerals used for making metals. These resources take millions of years to form. Once extracted and used, they are effectively gone on any timescale that matters for planning.
The distinction matters because it shapes how societies should manage each type. Renewable capital requires stewardship to prevent overuse. Non-renewable capital requires efficiency and, eventually, substitutes.
Global Natural Capital Is Declining
World Bank data tracking changes in natural wealth between 1995 and 2020 paints a clear picture. Renewable natural capital, the kind that can regenerate if sustainably managed, declined by more than 20 percent per capita over 25 years. Non-renewable natural capital (oil, gas, coal, and minerals) declined by 2.5 percent per capita over the same period.
That per-capita framing is important. Even where total stocks haven’t collapsed, population growth means each person has access to a smaller share of nature’s output. Forests are shrinking relative to the number of people who depend on them. Freshwater supplies are thinning. Fisheries are under increasing pressure. The decline in renewable capital is especially concerning because, unlike oil or coal, these are resources that should sustain themselves indefinitely under the right conditions.
Why It Matters for Health and Daily Life
Natural capital isn’t just an abstract economic concept. It directly shapes human health in ways that go beyond clean air and water. Urban green spaces provide cooling shade, absorb rainwater to reduce flooding, and create habitat for pollinators that support food production. Research from the Stanford Natural Capital Project has documented that nature experience boosts memory, attention, and creativity, along with happiness, social engagement, and a sense of meaning in life.
There’s also a physical activity connection that researchers are increasingly quantifying. People are more likely to walk an extra few blocks to enjoy a blooming garden or bike to work along a river path. The health benefits of that additional movement, from reduced cancer risk to better metabolic function, are significant. When natural capital degrades in a city (trees are removed, parks are neglected, waterways are polluted), people lose not just scenic views but measurable health benefits.
How Organizations Measure Natural Capital
For decades, natural capital was treated as free and limitless in economic models. That’s changing. Two major frameworks now guide how organizations and governments track their natural assets.
The Natural Capital Protocol
Designed for businesses, the Natural Capital Protocol walks organizations through four stages: Frame, Scope, Measure, and Value. In the Frame stage, a company identifies which natural capital impacts and dependencies are relevant to its operations, and what risks or opportunities an assessment might reveal. The Scope stage narrows the focus to the most significant dependencies. Measure and Value is where the actual accounting happens: quantifying how the business affects ecosystems, how external factors (like climate change or land use nearby) alter the natural capital it relies on, and selecting appropriate valuation techniques to put numbers on those relationships.
The process is iterative. Companies can retrace steps as they learn more, refining their assessment to match their decision-making needs. A food company, for instance, might discover that its supply chain depends heavily on pollinator populations and soil health in specific regions, then build that understanding into its sourcing strategy.
The UN System of Environmental-Economic Accounting
At the national level, the United Nations developed the System of Environmental-Economic Accounting (SEEA) to integrate economic and environmental data. It follows a similar structure to the System of National Accounts that countries already use to calculate GDP, but extends it to cover environmental assets. SEEA tracks land accounts, water accounts, air emissions, energy flows, material flows, and ecosystem condition across agriculture, forestry, fisheries, and other sectors. The goal is to give policymakers a comprehensive view of the relationship between economic activity and the environment, using internationally standardized definitions so countries can compare results.
Natural Capital and Financial Risk
The connection between nature loss and financial risk has become a serious concern for investors and regulators. The Taskforce on Nature-related Financial Disclosures (TNFD), modeled after the climate-focused TCFD, now provides a framework for companies to report their exposure to nature-related risks. Its recommended disclosures are structured around four pillars: governance, strategy, risk and impact management, and metrics and targets.
The core idea is straightforward. If a company depends on natural capital (clean water for manufacturing, stable soils for agriculture, healthy oceans for seafood supply), degradation of that capital is a material financial risk. A chocolate company that relies on cocoa grown in regions experiencing deforestation and soil depletion faces supply disruptions. A coastal real estate portfolio loses value as wetlands and mangroves that buffer storm damage disappear. TNFD asks organizations to describe how they identify, assess, prioritize, and monitor these dependencies, treating nature loss with the same rigor they apply to currency fluctuations or interest rate changes.
This shift reflects a broader recognition: natural capital isn’t separate from the economy. It underpins it. When the stock declines, so does everything built on top of it.