ship banner

Science Menu

Antarctic Climate Change in the 21st Century (AntClim21)

 

The goals of AntClim21 are to deliver improved regional predictions of key elements of the Antarctic atmosphere, ocean and cryosphere for the next 20 to 200 years and to understand the responses of the physical and biological systems to natural and anthropogenic forcing factors. A primary form of data that we see being used by AntClim21 are the global coupled atmosphere-ocean model runs that form the basis of the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC). Palaeo-reconstructions of selected time periods, recognised as past analogues for future climate predictions, will be used to validate model performances for the Antarctic region.

More information about the aims and objectives of AntClim21 can be found in the Implementation Plan.

AntClim21 incorporates ITASE (the International Trans-Antarctic Scientific Expedition).

The overarching question of this proposal is: How will the Antarctic1 environment change over the 21st Century? This is an important issue both within Antarctic region and globally. To achieve this goal, AntarcticClimate21 will focus on three themes of research:

- Theme 1. Quantification of Antarctic climate variability.
- Theme 2. Climate model verification for the Antarctic region.
- Theme 3. Antarctic climate projection to 2100 AD

The Antarctic region has already experienced substantial changes with impacts on global sea level and ocean carbon uptake. To understand the significance of recent trends in the context of natural variability, it is important to consider change on a multi-century time scale. This proposal will focus on the past 2,000 years. In addition, we will take advantage of data and model outputs from earlier key time periods as they become available, such as the mid-Holocene, glacial terminations, warm interglacials, and the mid-Pliocene. Moreover, attribution of the causes of environmental change is a high priority. Assessment of how realistically climate models capture key forcings to help constrain climate model projections of future change. The overall aim is to provide improved projections of the magnitude and patterns of change to Antarctica’s physical environment as a result of global change over the next 100+ years. 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. 

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.