Written by Shawna Healey
The economic benefits of preserving nature now outweighs the potential profit for exploiting the land for human use.
A collaborative effort between a team of international experts led by the University of Cambridge and the Royal Society for the Protection of Birds (RSPB) have analysed dozens of sites spanning six continents, including Kenya, Fiji, China, and the UK, comparing the value of protecting nature at the sites with that of exploiting it.
The team at the University of Cambridge are part of the Cambridge Conservation Initiative, a unique collaboration between the university and nine leading internationally focused biodiversity conservations based in and around Cambridge.
A previous study analysing the same subject was published in 2002 but only looked at five sites.
The findings published in the journal Nature Sustainability comes after the release of Professor Sir Partha Dasguputa’s review that calls for biodiversity to be placed at the heart of global economics.
For this study, the scientists calculated the monetary worth of each site’s “ecosystem services”. This included carbon storage, flood protection, as well as likely dividends from converting it for production of goods such as crops and timber.
The team initially concentrated on 24 sites and compared their “nature-focused” and “alternative” states by working out the annual net value of a range of goods and services for each site under each state, then projected the data over the next 50 years.
Andrew Balmford, Professor of Conservation Science at Cambridge and senior author of the research said: “Current rates of habitat conversion are driving a species extinction crisis unlike anything in human history.”
“Even if you are only interested in dollars and cents, we can see that conserving and restoring nature is now very often the best bet for human prosperity. The findings echo at an operational scale the overall conclusions drawn by the Dasgupta Review.”
The study found that the major economic benefit of natural habitats comes from their regulation of the greenhouse gases driving climate change, including the sequestration of carbon.
Assuming each tonne of carbon carries a cost of $31 (£22.26) to global society a sum many scientists now consider conservative then over 70% of the sites have greater monetary value as natural habitats, including 100% of forest sites.
If carbon is assigned the paltry cost of $5 (£3.61) a tonne, 60% of the sites still provide greater economic benefit when unconverted or restored to natural habitats. If carbon is removed completely from calculations, researchers found that almost half (42%) of the 24 sites are still worth more to us in their natural form.
In 2011, the scientists devised Toolkit for Ecosystem Service Site-based Assessment (TESSA), enabling users to measure and where possible assign a monetary value to services provided by a site under nature, including: clean water, nature-based recreation, and crop pollination for example.
The new study combines results from 62 applications of TESSA around the world. Some 24 sites include relatively detailed economic data, and a further 38 sites has enough data to gauge whether services would increase or decrease following conversion of the site.
Most sites were either forest or wetland. For natural habitats, the scientists looked at similar near-by locations where conversion had occurred and compared economic outputs including those driving the conversion – in both areas.
At sites already “modified” by humans, existing outputs were compared to the value if the site was restored to nature.
Results for the best-studied sites are likely to be conservative, say scientists. Many ecosystem services were not easily evaluated economically, yet data across all 62 sites shows they were typically delivered at a much higher level by natural habitats. Taking their value into consideration would “make the economic case for conservation overwhelming.”
Lead author Dr Richard Bradbury from the RSPB, and honorary fellow at the University, said: “Stemming biodiversity loss is a vital goal, but nature also fundamentally underpins human wellbeing.
“We need nature-related financial disclosure, and incentives for nature-focused land management, whether through taxes and regulation or subsidies for ecosystem services.”
The team found that if Nepal’s Shivapuri-Nagarjun National Park lost its protection and was converted from forest to farmland, it would cut carbon storage by 60% and reduce water quality by 88%, along with other costs, leaving an $11m (£7.9m) a year deficit.
The study also revealed that Hesketh Out Marsh, a saltmarsh near Preston, UK, is worth over $2000 (£1,443) per hectare annually in emissions mitigation alone, outweighing any forgone income from crops or grazing.
Conserved or restored habitats were strongly associated with greater overall “net present value” in 75% of the 24 main sites when compared with their human-dominated alternative state.
Researchers also divided goods and services into those that are a common resource and the “private and toll” goods of benefit to only a few people. The value of common goods was greater for natural habitats in 92% of the 24 sites.
Habitats even provided greater economic benefits in terms of some private goods, e.g., harvested wild plants – in 42% of the main sites.
Study co-author Dr Kelvin Peh of the University of Southampton said: “People mainly exploit nature to derive financial benefits. Yet in almost half of the cases we studied, human-induced exploitation subtracted rather than increased economic value.”
Study co-author Anne-Sophie Pellier from BirdLife International added: “Our results add to evidence that conserving and restoring key biodiversity areas makes sense not only to safeguard our natural heritage, but also by providing wider economic benefits to society.”