New LIFE metric reveals striking variations in extinction risk for c. 30,000 species
A new a tool shows more clearly than ever before where people are changing extinction risks for nearly 30 000 species and where conservation actions might be most effective. The Land-cover change Impacts of Future Extinctions metric (LIFE metric) offers unprecedented insights on a global scale into how changes in land-use – like converting forest to arable land, and vice versa – affect a species’ chance of survival.
Through high-performance computing, the LIFE metric maps striking variations in global extinction risk: converting 1km2 of forest in South America to arable land causes around 35 times more extinctions than converting 1km2 in Europe, on average.
The international team of researchers from University of Cambridge, Stockholm Environment Institute York (SEI York), UNEP World Conservation Monitoring Centre, BirdLife International and the Institute of Ecology and Biology, Chile – set out the new tool in Philosophical Transactions B (https://doi.org/10.1098/rstb.2023.0327).
The LIFE metric is a quantitative measure of the positive or negative impacts of two particular actions on the overall extinction risk to all assessed species in a unit of habitat: converting remaining vegetation to arable land or restoring farmland to natural habitat.
Lead author Dr Alison Eyres, University of Cambridge said: “LIFE incorporates three things that conservationists agree are important: species richness, rarity and past loss. Previously, the impacts of habitat loss have often required bespoke analysis that are computer, time and money intensive. LIFE allows the effects of various actions to be measured, without the need for end users themselves to have access to high performance computing”.
LIFE’s novel calculations account for changes in species’ ranges prior to human activity, rather than only calculating from present habitats. Utilizing data from the International Union for Conservation of Nature (IUCN), LIFE scores are generated from a formula which accounts for current extinction risk and the fact that land-use change impacts are not linear: the more habitat is lost, the greater the impact on a species’ extinction risk. The LIFE score is the sum of the changes in extinction risk for all species present in a given unit of habitat as a result of changing land use there.
“What really interests me is how to provide information that’s both credible and useful to stakeholders. LIFE’s capacity to drill down into extinction risk for individual vertebrate species provides crucial data for decision-makers. It’s particularly brilliant because it elevates the importance of species for whom loss of any further range is going to be most damaging”, said co-author Dr Jonathan Green, SEI York.
Senior author Professor Andrew Balmford, University of Cambridge said “LIFE reveals that there is huge variation in biodiversity impacts of agriculture – which has more impact on biodiversity than any other human activity. This should make us think carefully about where we choose to source commodities from, and where we prioritise conservation”.
The paper also shows that LIFE scores can be applied with a high degree of certainty to actions ranging in area from 0.5km2 to 1000km2. This robustness has important applications for the business sector: “Companies have recently been mandated to incorporate biodiversity in their business models by reporting their biodiversity impacts, dependencies and risks”, said co-author Dr Paz Durán, Institute of Ecology and Biology, Chile, adding, “LIFE is not free of limitations, but the best way to address these is by implementing it in real problems.”
The next step, and an urgent priority is making the data as accessible as possible to decision-makers. “We’re committed to refining, maintaining and scientifically validating [LIFE’s] integrity for downstream uses such as land-use planning and agricultural impacts”, said co-author Professor Anil Madhavapeddy, University of Cambridge.
Previously, the research team produced similar models on a smaller scale for land-use in the Brazilian Cerrado, but found scaling the model a challenge. LIFE’s use of computing technology marks a huge leap as the metric goes global: “When we started it took us three weeks to calculate the extinction risk of all species; we got it down to three days, and now we can do it in a day”, said co-author Dr Michael Dales, University of Cambridge.
The improved measure comes as global biodiversity grows increasingly precarious: in 2024, the WWF’s Living Planet report revealed a 73% decline in average size of global wildlife populations since 1970.
Also see the feature about this article on Mongabayhere
Text was written by Anjali Vyas-Brannick, Stockholm Environment Institute – York
Photo credit: Bernd Dittrich@Unsplash