To assess future climate change impacts on ecosystems, we use models to project their future distribution. Comparing the trends in the observed changes against the projections can help assess the strength of the model projections. In this box, we compare observed trends of changes in ecosystem structure to projections highlighted in previous IPCC reports, specifically AR3 , AR4  and AR5 . We use this to assess how well the projections are matching up with observed changes. The map represents studies documenting observed changes in common plant functional groups . Studies documenting changes in plant functional groups were collated from published papers in natural and semi-natural areas. Studies were included if climate change or interactions between climate change and land use showed a causal link to the observed change . Studies were excluded if the changes were only from landscape/land use transformation . In each paper, we recorded the geographical location and type of functional change, and noted the causes. Observed changes are plotted onto a biome map derived from the WWF ecoregions database . Trends in changing plant functional types are good indicators of potential biome shifts and are used to assess how observations match up with projections.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report