Antarctic Climate Change in the 21st Century (AntClim21)

Terms of Reference

The objectives of AntarcticClimate21 are to produce improved projections of the magnitude and patterns of change to Antarctica’s physical environment over the next 100+ years as a result of changes in forcings, such as an increase in the concentration of greenhouse gases and the recovery of the ozone hole. The assessment will be based on Intergovernmental Panel on Climate Change (IPCC) Assessment Report Five (AR5) Representative Concentration Pathways (RCP) and updated scenarios as they become available. To achieve this goal, AntarcticClimate21 will focus on three themes of research:

1. Quantification of Antarctic climate variability. This theme concentrates on quantifying and understanding natural and anthropogenically-forced climate change by utilising observational data, proxy records, and climate models. It will investigate rates of change, types of trends (linear, thresholds, accelerating), the onset of trends, and identification of contributing or alleviating feedback mechanisms. We will focus on key aspects of the Antarctic environment (e.g. temperature, circulation patterns and strength, mass balance, snow accumulation, sea ice extent, ocean circulation, sea surface temperature, ocean salinity).

2. Climate model verification for the Antarctic region. This theme will use existing modelling results and instigate new modelling initiatives to evaluate and improve the ability of models to reconstruct past Antarctic climate conditions.

3. Antarctic climate projection to 2100 AD. The aim of this theme is to provide model output for short term changes (decadal estimates) to longer term projections (50-100+ years). We will focus in particular on the four IPCC AR5 RCPs which bracket low to high emission scenarios using models that are identified in theme 2 to show high skill for the Antarctic region.