Aim Environmental changes may have important implications for biodiversity in Europe. This study aimed to provide quantification of changes in regional climate during the 20th century and provide scenarios of future changes in CO2 concentration and climate for the 21st century as an input to models used to study risks to biodiversity in the EU-funded ALARM project.
Methods Monthly time series of eight climate variables (maximum, mean and minimum temperature, precipitation, cloudiness, humidity, growing degree days and evapotranspiration) interpolated to a regular 10′ grid, and of global atmospheric CO2 concentration were constructed for the period 1901–2100. These combine observations from the 20th century with model projections for the 21st century. Projections were selected to capture a range of both climate model and SRES (Special Report on Emissions Scenarios) emissions uncertainties.
Results Averaged over Europe, the scenarios describe changes in mean annual temperature by the end of the 21st century relative to 1961–90 that range between 3.0 and 6.1 °C. Annual precipitation is projected to increase in northern Europe (+5 to +13%) and decrease in southern Europe (−17 to −7%). An additional scenario describing the collapse of the North Atlantic thermohaline circulation exhibits a sharp cooling over much of Europe and a drying in most seasons.
Main conclusions The climate scenarios presented are consistent with socio-economic storylines developed in parallel, and include a high-emissions case, CO2 stabilization and a high-impact ‘surprise’ scenario, involving the collapse of the North Atlantic thermohaline circulation. They embrace a number of key climate and related variables required for studying the impacts of climate change, offer continental coverage and capture a range of uncertainties in future European climate that are also consistent with the most recent climate projections assessed by the Intergovernmental Panel on Climate Change. The scenarios have already been applied in numerous studies of the impacts of climate change on biodiversity, some reported in this special issue.