Ecosystem Services & Natural Capital

Ecosystem Services and Natural Capital

What Are Ecosystem Services?

Ecosystem services are the contributions that ecosystems make to human well-being, both directly and indirectly. The concept was systematised by the Millennium Ecosystem Assessment (MA, 2005), a landmark study by more than 1,300 scientists commissioned by the United Nations, and further refined by TEEB (The Economics of Ecosystems and Biodiversity) and IPBES.

The most widely used classification system organises ecosystem services into four categories, though IPBES has since adopted the broader concept of "Nature's Contributions to People" (NCP) to capture cultural, relational, and non-material dimensions that purely economic framings can miss.

The Four Categories of Ecosystem Services

1. Provisioning Services

Provisioning services are the physical products that ecosystems produce and that humans harvest for consumption or production. They are the most directly visible and economically quantifiable category.

• Food: Fish, wild game, fruits, nuts, seeds, and livestock supported by natural pastures. Global fisheries and aquaculture provide protein for over 3 billion people.
• Fresh water: Forests and wetlands regulate the quantity and quality of freshwater supply. Over 2 billion people rely on groundwater as their primary drinking source, replenished by functional ecosystems.
• Timber and fibre: Forests supply wood, paper, cotton, and other plant fibres. Global roundwood production exceeds 4 billion cubic metres per year.
• Genetic resources: Wild species provide the biological templates for crop breeding, pharmaceuticals, and biotechnology. The Nagoya Protocol governs access to these resources.
• Medicinal resources: An estimated 25,000 plant species are used in traditional medicine; around 50,000 species have documented medicinal properties.

2. Regulating Services

Regulating services are the benefits obtained from the regulation of ecosystem processes. They are often invisible in market prices but represent enormous economic value when lost.

• Climate regulation: Forests, peatlands, and oceans sequester carbon and regulate regional and global climate. Tropical forests alone store an estimated 250 billion tonnes of carbon.
• Flood regulation: Wetlands, floodplains, and forests absorb rainfall and slow runoff. The U.S. Army Corps of Engineers estimated that New York-area wetlands provide $1 billion annually in flood damage protection. Globally, wetlands provide flood mitigation valued at $3.4 trillion per year.
• Water purification: Riparian vegetation and wetlands filter sediment, nutrients, and pollutants. New York City's investment of $1.5 billion in protecting Catskill watershed forests saved the city an estimated $8-10 billion in water treatment infrastructure.
• Pollination: Wild bees, butterflies, bats, and birds pollinate roughly 75% of the world's food crop types. The annual economic value of pollination services ranges from $235 to $577 billion globally.
• Pest and disease regulation: Natural predator communities limit populations of agricultural pests and vectors of human disease. The collapse of vulture populations in South Asia following diclofenac poisoning led to feral dog population increases and a rabies resurgence estimated to have caused $34 billion in public health costs between 1993 and 2006.

3. Cultural Services

Cultural services are the non-material benefits people obtain from ecosystems through spiritual enrichment, cognitive development, reflection, recreation, and aesthetic experiences. They are often dismissed as soft or unquantifiable, but evidence increasingly shows they generate material economic value.

• Recreation and tourism: Nature-based tourism represents one of the fastest-growing tourism segments. National parks in the United States alone generate over $41 billion in economic output annually and support nearly 400,000 jobs.
• Spiritual and cultural identity: Many Indigenous communities and cultures define their identity through relationship with specific ecosystems and species. TNFD explicitly requires organisations to engage with Indigenous Peoples and Local Communities in assessing nature-related risks.
• Mental and physical health: Access to green and blue spaces is associated with reduced rates of depression, anxiety, obesity, and cardiovascular disease. The UK's Natural England estimates that Green Social Prescribing saves the NHS approximately £6,000 per person per year in health costs.

4. Supporting Services

Supporting services are the fundamental ecosystem functions that underpin all other services. Unlike provisioning or regulating services, their effects on humans are indirect and occur over long timescales.

• Soil formation: Healthy topsoil, developed over thousands of years through the action of decomposers, bacteria, fungi, and soil fauna, is the foundation of agricultural production. An estimated 24 billion tonnes of fertile topsoil are lost globally each year to erosion.
• Primary production: Photosynthesis by plants and phytoplankton converts solar energy into organic matter, fuelling nearly all food webs on Earth.
• Nutrient cycling: Microbial communities decompose organic matter and cycle nitrogen, phosphorus, and other nutrients essential to plant growth. Without functioning nutrient cycles, agricultural systems require continuous external fertiliser inputs.
• Water cycling (hydrological cycle): Vegetation drives transpiration, which contributes to rainfall patterns across entire continents. Modelling suggests that 30% of rainfall over the Amazon Basin is generated by moisture recycled within the forest itself.

Natural Capital: The Stock That Generates the Flow

If ecosystem services are the "flow" of benefits from nature, natural capital is the underlying "stock": the assets of soil, water, air, and living organisms that generate those flows. The natural capital framework, championed by organisations including the Natural Capital Coalition (now the Capitals Coalition) and underpinning TNFD's conceptual architecture, draws an explicit parallel with financial capital.

The TEEB Framework and Economic Valuation

TEEB (The Economics of Ecosystems and Biodiversity), launched in 2007 under UNEP and G8+5 auspices, developed one of the most influential frameworks for economic valuation of nature. Key TEEB findings include:

• The annual value of ecosystem services provided by the world's oceans was estimated at approximately $2.5 trillion per year if the ocean were a sovereign state, it would be the seventh-largest economy.
• The business benefits of investing in healthy ecosystems exceed the costs of conservation by 3 to 75 times depending on ecosystem type.
• Every $1 spent on watershed protection generates $7.5 to $200 in avoided water treatment costs.
• Global pollinators contribute services valued at approximately $577 billion annually to global food production.