Spatially and taxonomically explicit characterisation factors for greenhouse gas emission impacts on biodiversity

In life-cycle impact assessment, currently available characterisation factors (CF) for climate change impacts on biodiversity are highly simplified and do not consider spatial and taxonomic differentiation of species or local climate variability. We develop the first spatially and taxonomically specific CFs for the impacts of 20 GHGs on biodiversity considering 26,648 species across terrestrial and marine ecosystems. Generally, CFs are higher in the tropics, and marine species are affected more severely than terrestrial ones. When global GHG emissions from 2020 are assessed in a scenario with a global temperature rise of 3 degrees C by 2100, an average of 0.25%, 0.15% and 0.03% of species are negatively affected in 2100 from CO2, CH4, and N2O emissions, respectively, across the globe. The new CFs can be used at different levels of spatial and taxonomic aggregation to quantify co-benefits for biodiversity of climate change mitigation in tools such as life-cycle assessment, input-output analyses, or integrated assessment models.

Automated summary

In life-cycle impact assessment, the currently available characterisation factors for climate change impacts on biodiversity are oversimplified and overlook the spatial and taxonomic differences of species and local climate variability. A study has developed the first spatially and taxonomically specific characterisation factors for the impacts of 20 greenhouse gases on biodiversity, considering a wide range of species across terrestrial and marine ecosystems. The results indicate that characterisation factors are higher in tropical regions, and marine species are more severely affected than terrestrial species. When assessing global greenhouse gas emissions from 2020 in a scenario with a 3 degrees C temperature rise by 2100, a small percentage of species (0.25% from CO2 emissions, 0.15% from CH4 emissions, and 0.03% from N2O emissions) are projected to be negatively affected globally in 2100. These new characterisation factors can be used to quantify the co-benefits for biodiversity of climate change mitigation at different levels of spatial and taxonomic aggregation.