What is nature worth? If I think of an exquisite pasqueflower or a stirring starling murmuration, the answer is usually ‘priceless’, or ‘it cannot be valued’. Of course, that is why many parts of the world have laws to protect nature. I have a deep love of nature. But for me that value isn’t ‘crowded out’ by the more instrumental idea that nature also fundamentally underpins our health and wellbeing.
Many of us hope that broader values can become better considered when it comes to decisions that affect nature. However, even in the cold world of return on investment and benefit-cost ratios, land and sea management could be improved by a better understanding of nature’s value to people. This is amply documented in the monumental new Dasgupta Review for the UK Treasury and our new Nature Sustainability article adds to these arguments.
A toolkit for conservationists: For some time, I’ve been working with fellow members of the Cambridge Conservation Initiative, including colleagues at BirdLife International, to develop a toolkit that enables conservation practitioners to understand the value of sites when faced with impending management decisions.
TESSA (Toolkit for Ecosystem Service Site-based Assessment) enables them to measure and, where possible and appropriate, assign a monetary value to the benefits that a site provides for people – things like clean water provision, nature-based recreation, flood protection, harvested wild goods, and so on. Critically, benefits are compared between the conserved or restored state of a site, and the most plausible alternative state if the site were more dominated by human land-use.
Having made TESSA available, we examined the results from a geographically, ecologically and contextually diverse sample, spread across six continents, to see if any general patterns have emerged. Most sites were forests or wetlands, with a small number of other habitats, and included both sites that were being conserved for their conservation value and sites that were being restored for nature. For 24 sites, we had monetary data on most services, while 38 other sites provided data just on the likely change in direction of provision of each service between states.
These services included the most important benefits from marketed goods, as well as one or more unmarketed public goods delivering local or global benefits. Wherever possible, costs of restoration and management activities were also included.
Net economic benefits of conservation and restoration: For the 24 sites with monetary estimates, conservation almost universally provided greater net value than the alternative state, especially for forests. Ecological restoration also tended to provide greater value than the alternative state. Even with a social cost of carbon of $0/tonne*, conservation or restoration was more valuable than the alternative state at 42% of sites, rising to over 70% (including 100% of forest sites) if we used a widely accepted median value of $31/tonne.
* The social cost of carbon is an estimate of the damage caused by an additional tonne of carbon in the atmosphere - on agricultural production, coastal damage, human health etc. There is a wide variation in estimates, resulting from differences in expected scale of future damage per se and from different weighting of the well-being of future people relative to the well-being of present people.
Fairness from nature: We next divided services into non-excludable (where the wider public can typically benefit), and excludable goods (where the benefits are captured by relatively few). For both conservation and restoration, the value of non-excludable goods tended to be greater under conservation/restoration than the alternative state. Contrary to what might be expected, given that change is usually driven by extraction of private goods, the value of excludable goods was also regularly higher under conservation/restoration than in the alternative state.
Further support for conservation and restoration: Across the main 24 sites, of 19 cases where a service was assessed for directional change but not monetised (15 of these relating to water quality, water provision or flood risk mitigation), only two cases were greater in the alternative state. Further, at all 38 of the other sites, more services were qualitatively higher or equal under the conservation/ restoration state than the alternative state. This suggests that the 24 main sites are broadly representative of a wider pool.
For decision-makers aiming to maximize profit, contrasting net benefits of two states is informative. But decisions about site management also reflect benefit-cost ratios of alternative options. We found that benefit-cost ratios also generally favour both conservation and ecological restoration as much as the alternative state.
Reflections: These analyses show that both conservation and ecological restoration bring considerable net benefits, regardless of the habitat or type of ecosystem state change being considered. However, conservation and restoration did not have universally greater net value than alternative land uses, so more work is needed to identify the situations when a nature focus does and does not pay. Nonetheless, within the broad habitat and geographic range present in our data, our analyses show that we have typically passed the point where the benefits of further change from nature towards human-modified uses exceed the costs to society.
Despite these overall results, the alternative state was often more valuable when only excludable goods were considered. Our findings therefore provide a strong justification for incentives to nudge private landowners towards decisions that favour nature-focussed land management, to enhance overall social value. This could include negative incentives such as taxes and regulation, or positive incentives such as subsidies and payments for ecosystem services.
To turn persuasive evidence into effective incentivization requires focussed and committed engagement and relationship-building between data-gatherers and decision-makers, to maximize trust and knowledge legitimacy. This includes both individuals and communities most affected by the management decision and policy makers who can provide incentives that alter their decision-making context. Such multi-stakeholder engagement is a vital component of the TESSA assessment process.
Embedding better documentation of the full range of benefits and beneficiaries in such an engagement process is essential if future land and water management decisions are to stem the ongoing loss of biodiversity while supporting human prosperity.
This is a version of a blog first posted on the RSPB website at: https://bit.ly/3bnXIql If you like to be kept up to date with the RSPB’s latest science news, Email here with the heading 'enewsletter' to be added to our quarterly enewsletter!