Abstract. To support the assessments of the Intergovernmental Science-Policy Platform
on Biodiversity and Ecosystem Services (IPBES), the IPBES Expert Group on
Scenarios and Models is carrying out an intercomparison of biodiversity and
ecosystem services models using harmonized scenarios (BES-SIM). The goals of
BES-SIM are (1) to project the global impacts of land-use and climate change
on biodiversity and ecosystem services (i.e., nature's contributions to
people) over the coming decades, compared to the 20th century, using a set of
common metrics at multiple scales, and (2) to identify model uncertainties
and research gaps through the comparisons of projected biodiversity and
ecosystem services across models. BES-SIM uses three scenarios combining
specific Shared Socio-economic Pathways (SSPs) and Representative
Concentration Pathways (RCPs) – SSP1xRCP2.6, SSP3xRCP6.0, SSP5xRCP8.6 – to
explore a wide range of land-use change and climate change futures. This
paper describes the rationale for scenario selection, the process of
harmonizing input data for land use, based on the second phase of the Land
Use Harmonization Project (LUH2), and climate, the biodiversity and ecosystem
services models used, the core simulations carried out, the harmonization of
the model output metrics, and the treatment of uncertainty. The results of
this collaborative modeling project will support the ongoing global
assessment of IPBES, strengthen ties between IPBES and the Intergovernmental
Panel on Climate Change (IPCC) scenarios and modeling processes, advise the
Convention on Biological Diversity (CBD) on its development of a post-2020
strategic plans and conservation goals, and inform the development of a new
generation of nature-centred scenarios.
The impact of climate change on California’s ecosystem services
