Past Baselines

Antarctic-wide sea-ice reconstructions from ice cores and marine records, including those by our team members, have made important contributions to our understanding of past environmental and ecological change.

Sea-ice changes are complex drivers of regional and global climate change. Yet, sea-ice observations are short (reliable satellite data only exist since 1979) and natural variability is high. This means that the ability of climate models to capture observed sea-ice behaviour and to project future trends remains poor. To address this, we are extending time-series of environmental proxies to 2,000 years to provide baselines of near-instrumental quality, to assess natural variability in coupled air-ocean-Earth system models against recent trends in sea ice, and attribute their drivers, by:

• Working with international collaborators and sharing capability (e.g. bases, ships, drilling systems) to recover new high-resolution (sub-seasonal to centennial) ice and sediment cores from existing and new sites in sensitive regions of environmental change.
• Using this new knowledge, tested against modern observations, to inform future projections, improve sea ice in models and quantify the impacts on biological indicators.
• Applying emerging technological breakthroughs, such as ancient DNA, machine learning, analytical capability, and virtual ice cores.
• Extrapolating our Ross Sea improvements to circum-Antarctic sea-ice behaviour using new indirect sea-ice reconstructions.