Global trends and scenarios for terrestrial biodiversity and ecosystem services from 1900 to 2050

The 20th century saw rates of biodiversity loss high enough to qualify as a sixth mass extinction. Climate change now further threatens species and ecosystem services. Pereira et al. forecasted changes in both biodiversity loss and ecosystem services to 2050 and compared them with changes from 1900 to 2015, combining results from 13 different models. Across three shared socioeconomic pathway scenarios, rates of biodiversity decline from land-use change are expected to be lower than in the 20th century but much higher when climate change is considered. Provisioning ecosystem services (i.e., materials) are expected to increase, but regulating services (e.g., pollination) decline under most scenarios. Outcomes depend on the scenario, suggesting that policies can make a difference. 

Based on an extensive model intercomparison, authors assessed trends in biodiversity and ecosystem services from historical reconstructions and future scenarios of land-use and climate change. During the 20th century, biodiversity declined globally by 2 to 11%, as estimated by a range of indicators. Provisioning ecosystem services increased several fold, and regulating services decreased moderately. Going forward, policies toward sustainability have the potential to slow biodiversity loss resulting from land-use change and the demand for provisioning services while reducing or reversing declines in regulating services. However, negative impacts on biodiversity due to climate change appear poised to increase, particularly in the higher-emissions scenarios. This assessment identifies remaining modeling uncertainties but also robustly shows that renewed policy efforts are needed to meet the goals of the Convention on Biological Diversity.