For years, institutional investors have treated nature as someone else's problem. Climate change was considered financially material. Biodiversity loss was viewed as an environmental concern. Forests, wetlands, watersheds, soils, and pollinators were important, but outside the boundaries of mainstream investment decision-making.
That framing is becoming increasingly difficult to sustain. Most institutional portfolios already carry some natural-resource exposure, through commodities, timber REITs, or farmland sleeves. But these instruments typically capture only one dimension of the value that biological systems produce. They miss what natural assets, properly defined, actually are. The question is no longer whether investors should care about nature. The question is whether investors can afford not to.
What Are Natural Assets?
Before making the investment case, it is worth being precise about definitions. A natural asset is a biological production system — a forest, agricultural land, wetland, or waterway — whose value flows from two interlocking return streams: (a) the sustainable harvesting of natural commodities (timber, rubber, agricultural products) and (b) the monetisation of the ecosystem services those same biological systems generate (carbon sequestration, biodiversity credits, water regulation, flood protection).
Both streams originate from the same living asset and both compound over time as that asset is sustainably managed. The analytical framework for understanding these assets draws on a growing literature on ecosystem asset accounting (Hein et al., 2016; Leach et al., 2019), but the investment case rests on observable cash flows: commodity revenues, ecosystem service markets, and the long-run appreciation of biological capital.
This dual revenue structure is what makes natural assets structurally distinct — not the presence or absence of commodity production, but its combination with ecosystem service value. A conventional timber REIT is structured to maximise extraction yield; it captures one dimension of the biological system's productive capacity while leaving the ecosystem service dimension largely unmonetised.
A natural asset, properly structured, captures both, and in doing so carries a different risk profile, a different governance requirement, and a different time horizon. As Birch and Ward (2022) observe in their work on assetisation, converting biological systems into investable instruments requires capturing the full productive capacity of the asset, not just its harvest value.
Nature Underpins the Economy
Investors spend enormous effort understanding the factors that drive economic growth and corporate profitability. They analyse interest rates, inflation, demographics, technology, labour markets, and geopolitics.
Yet one of the most fundamental drivers of economic value receives far less attention: natural capital. Natural systems provide services that economies rely upon every day — water regulation, soil fertility, pollination, flood protection, carbon sequestration, coastal resilience.
These services are rarely priced appropriately, but they are far from free. When ecosystems deteriorate, economic productivity suffers, agricultural yields decline, water becomes scarcer, supply chains become more vulnerable, insurance losses increase, infrastructure becomes less resilient.
Nature is not a peripheral issue. It is part of the productive foundation of the economy. The Dasgupta Review (2021) estimated the total economic value of nature's services at multiples of global GDP, and concluded that current rates of ecosystem degradation represent a vast unpriced liability sitting across every balance sheet.
The Real Nature Risk for Investors
Much of the discussion around nature has focused on sustainability. Institutional investors should instead think about portfolio risk. Nature loss creates risks in at least four categories.
- Physical risks: droughts, water scarcity, soil degradation, and ecosystem collapse can directly affect companies and assets.
- Transition risks: governments are accelerating regulations related to biodiversity, land use, deforestation, and ecosystem protection.
- Liability risks: environmental litigation is expanding globally.
- Systemic risk: the fourth category is the most consequential.
Unlike most investment risks, biodiversity loss and ecosystem degradation affect entire economic systems. For large pension funds, sovereign wealth funds, and insurers that effectively own a slice of the whole economy, these risks cannot be diversified away. In that sense, nature is increasingly similar to climate change: a source of portfolio-wide risk that conventional diversification cannot address.
Nature Is Also an Opportunity
The investment case for nature is not solely defensive. Natural assets can also generate returns. Traditional examples include timberland, farmland, sustainable forestry, and water infrastructure.
More recently, new opportunities have emerged through carbon markets, biodiversity credits, ecosystem restoration, regenerative agriculture, blue carbon projects, and natural infrastructure. These investments share a common characteristic: they generate value from ecological performance. In other words, nature itself has become part of the investment thesis.
The Financial Case
The academic evidence on natural assets as portfolio components is now substantial. Timberland has delivered moderate, stable returns with demonstrated recession resilience, a combination that is rare among real assets (Chudy and Cubbage, 2020). Research on portfolio diversification confirms that private timberland has historically maintained a near-zero correlation coefficient with public equity markets (Lutz, 2024), with a 5–10% allocation shifting the mean-variance efficient frontier upward (Fiera Capital, 2025).
Furthermore, globally diversified timberland portfolios achieve competitive risk-adjusted returns: Xidonas and Essner (2022) find Sharpe ratios of approximately 0.80 at the risk-adjusted optimum, with regional diversification across North America, Latin America, and Asia improving efficiency further. Busby et al. (2020) demonstrate that such portfolios substantially outperform conventional real-asset benchmarks on a risk-adjusted basis.
The inflation-hedging properties of natural and real assets are also documented, though regime-dependent. Mendoza (2023) and Salisu et al. (2020) find that real assets provide partial inflation protection, with performance varying across monetary regimes. Nasreddine and Zouari (2024) confirm the hedging characteristics of real estate and alternative assets using wavelet quantile correlation analysis, finding that natural assets exhibit properties that complement rather than replicate conventional inflation-linked allocations.
The portfolio logic is structural: natural capital's return drivers are biologically and ecologically determined, not financially engineered. That is precisely why the diversification properties are persistent rather than cyclical, and why the case for a dedicated allocation is fundamentally different from the case for any other real-asset sleeve.
Is Nature a New Asset Class?
This is where the debate becomes interesting. Most institutional investors still classify natural assets within existing categories. Timberland is considered a real asset. Farmland is typically treated as a real asset. Carbon credits may be viewed as commodities. Restoration projects often sit within private markets. From this perspective, nature is not an asset class. It is a theme.
But history suggests that themes can become asset classes. Infrastructure offers an instructive example. Several decades ago, infrastructure investments were often grouped within private equity or real estate. Over time, investors recognised that infrastructure had distinct characteristics: long-duration cash flows, inflation protection, unique risk drivers, strategic portfolio benefits. Eventually, infrastructure became a dedicated allocation within many institutional portfolios. Nature may follow a similar path, and the structural argument is at least as strong.
Natural assets as defined here — biological production systems generating returns through both commodity output and ecosystem services — have cash flows that derive from biological productivity, not from rents on built structures. Their risk drivers are different. Their governance requirements are different. Their time horizons are different.
In the language of Birch and Ward (2022), they represent a distinct form of assetisation: the conversion of living biological systems into investable instruments whose value compounds through careful stewardship rather than depletes through extraction.
Whether or not the institutional taxonomy catches up, the portfolio evidence is already clear. Natural capital assets function as portfolio optimisers by improving risk-adjusted returns, reducing covariance with public markets, and providing asymmetric downside protection. The argument for a dedicated allocation rests on those properties, not on definitional convention.
The Missing Ingredient: Investability
If nature offers both risk management and return opportunities, why are institutional allocations still relatively small? The answer is not a lack of capital. Global institutional investors manage hundreds of trillions of dollars.
The challenge is investability. Most nature-based projects remain too small, too fragmented, too difficult to measure, and too structurally complex for institutional mandates. The barriers are well documented: inadequate classification and accounting standards, valuation methodologies not aligned with investor decision processes, structuring challenges that prevent scale, mandate and fiduciary constraints, and governance frameworks unable to integrate multi-stakeholder, multi-jurisdictional assets (Sheikh et al., 2025; Toxopeus and Polzin, 2021). Interest in nature is growing far faster than actual capital deployment precisely because these structural barriers remain intact.
What Needs to Change?
Two developments could fundamentally reshape nature investing over the next decade.
1. Better Measurement
Investors need confidence that environmental outcomes are real, measurable, and comparable. The development of nature-related disclosure frameworks, most notably the TNFD recommendations (2023), and ecosystem accounting standards is a crucial step forward, but standardised, auditable measurement at the asset level remains the critical gap.
2. More Investable Structures
Project aggregation, blended finance vehicles, and specialised investment intermediaries can transform fragmented projects into institutional-grade portfolios. The structural innovation required is understood; the challenge is deployment at scale.
The Bigger Question
The most important question for investors may not be whether natural assets constitute a separate asset class. It may be whether the concept of an asset class is even the right lens. Nature influences every sector of the economy. It affects infrastructure, agriculture, real estate, insurance, energy, consumer goods, and sovereign risk. Nature should not be viewed as a niche allocation.
It should be viewed as a foundational layer of economic value that cuts across entire portfolios. If that is true, then nature is not simply another sustainability theme. It is a core investment issue. Investors who understand that transition early will be better positioned to manage risk, identify opportunities, and build more resilient portfolios in a nature-constrained world.
The evidence that natural assets are investable, with measurable return properties, demonstrable diversification benefits, and a growing body of academic literature, is now substantial. But the structural barriers that have kept institutional capital on the sidelines remain real and well documented. In the next post in this series, we examine each of those barriers in turn, and the evidence that each has a tractable solution.
References and Further Reading
- Birch, K., & Ward, C. (2022). Assetization and the 'new asset geographies'. Dialogues in Human Geography, 14, 9–29.
- Busby, G., Binkley, C., & Chudy, R. (2020). Constructing optimal global timberland investment portfolios. Forest Policy and Economics, 111, 102083.
- Chudy, R., & Cubbage, F. (2020). Research trends: Forest investments as a financial asset class. Forest Policy and Economics, 119, 102273.
- Dasgupta, P. (2021). The Economics of Biodiversity: The Dasgupta Review.
- Fiera Capital (2025). Investing in Natural Capital Significantly Enhances Sharpe Ratio.
- Hein, L., et al. (2016). Defining Ecosystem Assets for Natural Capital Accounting. PLoS ONE, 11.
- Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (2019). Global Assessment Report on Biodiversity and Ecosystem Services.
- Leach, K., et al. (2019). A common framework of natural capital assets for use in public and private sector decision making. Ecosystem Services.
- Lutz, J. (2024). Timberland Investment Correlation and Diversification. Forisk Forest Research Quarterly, Q2 2024.
- Mendoza, A. (2023). The effectiveness of different asset types as a hedge against inflation. Boletin Economico.
- Nasreddine, A., & Zouari, Y. (2024). Inflation hedging: a comparative wavelet quantile correlation analysis. Journal of Property Investment & Finance.
- Organisation for Economic Co-operation and Development (2023). Scaling Up Nature-Based Solutions for Climate and Biodiversity.
- Salisu, A., Raheem, I., & Ndako, U. (2020). The inflation hedging properties of gold, stocks and real estate. Resources Policy, 66, 101605.
- Sheikh, H., et al. (2025). Unlocking private finance for nature. iScience, 28.
- Taskforce on Nature-related Financial Disclosures (2023). TNFD Recommendations.
- Toxopeus, H., & Polzin, F. (2021). Reviewing financing barriers and strategies for urban nature-based solutions. Journal of Environmental Management, 289, 112371.
- United Nations Environment Programme (2023). State of Finance for Nature.
- Wan, L., et al. (2015). Timberland Assets in a Portfolio of Risky Investments. AgEcon Working Paper Series.
- World Bank (2024). State and Trends of Carbon Pricing.
- World Economic Forum (2020). The Future of Nature and Business.
- Xidonas, P., & Essner, E. (2022). On ESG Portfolio Construction: A Multi-Objective Optimization Approach. Computational Economics.