2025-10-30 ケンブリッジ大学
ケンブリッジ大学動物学部のトーマス・ボール博士らは、食料生産が陸上脊椎動物3万875種の絶滅リスクに与える影響を定量化する指標「LIFE(Land-cover change Impacts on Future Extinctions)」を開発した。これは土地利用変化、特に農地化や森林伐採が生物多様性に及ぼす長期的影響を100年単位で評価する手法である。研究では、食料の種類や原産地によって絶滅リスクが大きく異なることを示した。たとえば、オーストラリアやニュージーランド産牛肉は英国産より30〜40倍高いリスクをもたらし、コスタリカ産コーヒーはブラジル産の約10倍生態系に負担をかける。一方で豆類など植物性たんぱく質の影響は極めて小さい。LIFE指標は英国政府の環境影響評価ツールにも採用され、農業・貿易政策の立案や企業の環境責任評価に活用可能とされる。研究チームは「食事選択そのものが生物多様性保全の最大の鍵」と強調している。
<関連情報>
- https://www.cam.ac.uk/stories/food-LIFE-and-global-species-extinction-risk
- https://www.nature.com/articles/s43016-025-01224-w
- https://royalsocietypublishing.org/doi/10.1098/rstb.2023.0327
種の絶滅リスクに対する食物の影響は3桁も異なる可能性がある Food impacts on species extinction risks can vary by three orders of magnitude
Thomas S. Ball,Michael Dales,Alison Eyres,Jonathan M. H. Green,Anil Madhavapeddy,David R. Williams & Andrew Balmford
Nature Food Published:09 September 2025
DOI:https://doi.org/10.1038/s43016-025-01224-w
Abstract
Agriculturally driven habitat degradation and destruction is the biggest threat to global biodiversity. Yet the impact of different foods and where they are produced on species extinction risks, and the mitigation potential of different interventions, remain poorly quantified. Here we link the LIFE biodiversity metric—a high-resolution global layer describing the marginal impact of land use on extinctions of ~30,000 vertebrate species—with food consumption and production data and provenance modelling. Using an opportunity cost framing, we estimate that the impact of producing 1 kg of different food commodities on species extinction risks varies widely both across and within foods, in many cases by more than an order of magnitude. Despite marked differences in per capita impacts across countries, there are consistent patterns that could be leveraged for mitigating harm to biodiversity. In particular, animal products and commodities grown in the tropics are generally much more impactful than staple crops and vegetables.
LIFE: 土地被覆の変化が地球規模の絶滅に与える影響をマッピングするための指標 LIFE: A metric for mapping the impact of land-cover change on global extinctions
Alison Eyres,Thomas S. Ball,Michael Dales,Tom Swinfield,Andy Arnell,Daniele Baisero,América Paz Durán,Jonathan M. H. Green,Rhys E. Green,Anil Madhavapeddy and Andrew Balmford
Philosophical Transactions of The Royal Society B Published:09 January 2025
DOI:https://doi.org/10.1098/rstb.2023.0327
Abstract
Human-driven habitat loss is recognized as the greatest cause of the biodiversity crisis, yet to date we lack robust, spatially explicit metrics quantifying the impacts of anthropogenic changes in habitat extent on species’ extinctions. Existing metrics either fail to consider species identity or focus solely on recent habitat losses. The persistence score approach developed by Durán et al. (Durán et al. 2020 Methods Ecol. Evol. 11, 910–921 (doi:10.1111/2041-210X.13427) represented an important development by combining species’ ecologies and land-cover data while considering the cumulative and non-linear impact of past habitat loss on species’ probability of extinction. However, it is computationally demanding, limiting its global use and application. Here we couple the persistence score approach with high-performance computing to generate global maps of what we term the LIFE (Land-cover change Impacts on Future Extinctions) metric for 30 875 species of terrestrial vertebrates at 1 arc-min resolution (3.4 km2 at the equator). These maps provide quantitative estimates, for the first time, of the marginal changes in the expected number of extinctions (both increases and decreases) caused by converting remaining natural vegetation to agriculture, and restoring farmland to natural habitat. We demonstrate statistically that this approach integrates information on species richness, endemism and past habitat loss. Our resulting maps can be used at scales from 0.5–1000 km2 and offer unprecedented opportunities to estimate the impact on extinctions of diverse actions that affect change in land cover, from individual dietary choices through to global protected area development.
This article is part of the discussion meeting issue ‘Bending the curve towards nature recovery: building on Georgina Mace’s legacy for a biodiverse future’.
