Climate action compatible with limiting global warming to 1.5°C could more than halve the combined loss of today’s climate refugia compared with current climate policies, even after accounting for the impacts of land-intensive climate mitigation.
Decisive climate action, compatible with limiting global warming to 1.5°C, could reduce the combined loss of climate refugia by more than half compared with current climate policies, according to new research published in Environmental Research Letters. The study examines 1.5°C-compatible scenarios, including those where temperatures temporarily exceed 1.5°C before declining again later this century.
“Climate refugia” are areas that remain climatically suitable for many of the species they currently support, staying relatively protected from the effects of climate change over time and making them an important conservation priority. However, some land-intensive mitigation measures, including afforestation and bioenergy production, can also place pressure on biodiversity by competing for land that functions as climate refugia.
The analysis explores the trade-off between biodiversity loss from warming and the biodiversity implications of land-intensive climate mitigation. It suggests that, at the global scale, avoiding further warming still delivers greater overall benefits for these important biodiversity areas.
Modelling climate and land-use change together
While previous studies have typically examined either climate change or land-intensive mitigation separately, the researchers in this study compared both impacts together across the same modelling framework. The international team included Jeff Price, Rachel Warren and Nicole Forstenhäusler from the Tyndall Centre for Climate Change Research, as well as scientists and researchers from institutions such as the Potsdam Institute for Climate Impact Research and the International Institute for Applied Systems Analysis.
For this methodological advance, the team used five integrated assessment models and explored different climate futures. By assessing both drivers together, the researchers were able to compare how warming and mitigation-related land-use change may affect the same areas of biodiversity importance.
The researchers also examined temperature overshoot – where global temperatures temporarily exceed a target before falling again. Overshoot is an increasingly important area of climate research because some pathways involve temperatures exceeding a target temporarily before declining later. The 1.5°C- and 2°C-compatible scenarios assessed in the study followed this peak-and-decline pattern, allowing researchers to explore how biodiversity might respond as temperatures decline. They found that biodiversity outcomes depend strongly on how well species and ecosystems are able to recover after peak warming, which highlights an important source of uncertainty.
There are also significant caveats that mitigation is not necessarily the same everywhere. Impacts vary substantially between regions, and different integrated assessment models produce different spatial patterns. The authors note that these differences reflect uncertainty in future land-use change and in how biodiversity may respond across different locations.
Implications for biodiversity conservation
The findings highlight the importance of considering both climate change and land-use change when planning biodiversity conservation. The authors emphasise that interpreting these global results requires attention to regional differences, uncertainty around ecological recovery after overshoot, and careful consideration of where land-intensive mitigation measures are deployed.
The study concludes that the future of today’s climate refugia will depend not only on how much the planet warms, but also on how far temperatures overshoot 1.5°C and how quickly they decline afterwards. Every additional increment of warming is expected to increase biodiversity loss.
‘Climate refugia implications of warming and land-intensive mitigation under overshoot’ was published in Environmental Research Letters by authors Ruben Prütz, Sabine Fuss, Jeff Price, Rachel Warren, Nicole Forstenhäusler, Yazhen Wu, Andrey Lessa Derci Augustynczik, Michael Wögerer, Tamás Krisztin, Petr Havlík, Florian Kraxner, Stefan Frank, Tomoko Hasegawa, Jonathan C Doelman, Vassilis Daioglou, Florian Humpenöder, Alexander Popp and Joeri Rogelj.
