Please join us for this Climate Coffee on

Future climate and sea level projections depend sensitively on Antarctic Ice Sheet response to ocean-driven melting and the resulting freshwater fluxes into the Southern Ocean. Circumpolar Deep Water (CDW) in the Southern Ocean is increasingly recognised as a crucial heat source for ice shelf melt. Quantifying past changes in the temperature of CDW is therefore of great benefit for modelling ice sheet response to past warm climates, and for putting recent and projected CDW temperature changes into context. Here we use marine sedimentary evidence to estimate CDW temperature changes over the last eight glacial-interglacial cycles (800,000 years). Estimated interglacial warming reached 0.6 ± 0.4 °C relative to present, while glacial cooling was typically −1.5 to −2 °C. The peak warmth occurred in the last interglacial, when sea-levels were a few metres higher than present. For comparison, observations indicate CDW warming of around 0.1 °C/decade since the 1990s, while climate projections (CMIP6 SP585) suggest 0.6 °C warming could already be reached by 2100.

Our speaker

David Chandler is a senior researcher at NORCE.

"I am primarily a glaciologist. My research focuses on processes at the base of ice sheets, particularly how friction, subglacial hydrology and sediment deformation influence ice flow. This work has included hydrological tracing experiments in Greenland, as well as numerical simulations of the Antarctic Ice Sheet with the ‘PISM’ ice sheet model.

I am also interested in how the response of the Antarctic Ice Sheet to previous climates can help us constrain projections of future ice sheet evolution.

One interesting period is the Last Interglacial (about 130,000 years ago), when the climate in the Southern Hemisphere high latitudes was only a little warmer than present, but sea level was several metres higher.

As part of the EU-funded TiPACCs project, I have been compiling climate reconstructions and running ice sheet simulations covering the last 2 glacial cycles (220,000 years). These simulations will help us understand Antarctica’s contribution to the higher sea-level during the last interglacial, and will provide an indication of whether the ice sheet could make this contribution again under projected future warming."

What is a Climate Coffee?

#climatecoffees are short (circa 40 min: 20 min talk + 20 min Q&A), relaxed meetings for scientists to share ideas, discuss methods, and communicate new results. They are open to speakers of all seniority; we especially encourage early-career scientists to become speakers. The Coffees are an exciting opportunity for scientists to build a network and disseminate recent results peer-to-peer. We invite researchers from across the climate science community to join us for this series of regular online knowledge exchange events.

Links to MS Teams

It will be sent via Eventbrite to you in due time.

Organisation

The Climate Coffees are organized by the Horizon Europe project OCEAN ICE, the Danish Meteorological Institute and the European Climate Research Alliance.

Warming of circumpolar deep water in Antarctica