An expedition to Antarctica will study the effects of global warming on the West Antarctic ice sheet.

The expedition is part of an international research programme known as ‘Sensitivity of the West Antarctic Ice Sheet to Two Degrees of Warming’ (SWAIS 2C), which aims to better understand the effects of varying degrees of warming on the West Antarctic Ice Sheet (WAIS) – Antarctica's largest current contributor to global sea-level rise.

The huge ice mass forming the WAIS has the potential to raise global sea levels by up to 5 metres as the climate warms. While the 2015 Paris Agreement commits countries to limit the global average temperature rise to well below 2°C above pre-industrial levels, recent research suggests that it is inevitable that the warming Southern Ocean will speed up the melting of parts of the WAIS regardless of our future carbon dioxide emissions.

However, we do not yet know how much or how fast the WAIS will melt. The group of international researchers, co-led by Professor Tina van de Flierdt, Head of the Department of Earth Science and Engineering at Imperial College London, will ‘drill into history’ as they embark on a once-in-a-lifetime mission to better understand the WAIS and the Ross Ice Shelf.

The international project, with a budget of $5.4 million allocated to operations and logistics alone, is funded by the International Continental Scientific Drilling Program (ICDP), with support from multiple international and national partners, including the Natural Environment Research Council (NERC) in the UK.

Using the past to learn about the future

Professor Tina van de Flierdt, Co-Chief Scientist of the project and Head of the Department of Earth Science and Engineering, said: “We will use the past to learn about the future. This knowledge is critical as humanity grapples with the unavoidable challenge of sea level rise.”

Dr James Marschalek, part of the SWAIS 2C team from Imperial’s Department of Earth Science and Engineering, said: “Earth's average surface temperature has already warmed by 1.2°C since the industrial revolution. This highlights the importance and urgency of our SWAIS 2C exploration.”

By drilling up to 200 metres below the seafloor, the researchers aim to recover a geological record of changing rock types from near the centre of West Antarctica that reflect environmental conditions at the time they formed. The team of researchers, engineers and drillers hope this will provide key insights into Antarctica's past and allow us to predict its future in a warming planet.

Dr Marschalek said: “Like time capsules buried deep beneath the ice, the ancient rocks we will recover during our expedition will provide crucial historical data. This data can improve our understanding of how sensitive ice sheets are to global change, and therefore how they might change and contribute to sea level rise in the future.”

‘A wake-up call to drive climate action’

More than 120 people from around 35 international research organisations are collaborating on the SWAIS 2C project, including around 25 early-career researchers. The project brings together researchers from the United Kingdom, New Zealand, the United States, Germany, Australia, Italy, Japan, Spain, Republic of Korea, and the Netherlands.

Professor van de Flierdt said: “SWAIS 2C will shape our understanding of Earth's past and future – guiding predictions and plans to adapt to sea level rise and hopefully serving as a wake-up call to drive climate action."

“Retrieving samples from such remote locations in Antarctica will allow us to build a much better picture of how Antarctic ice will respond to future warming, which parts will melt first, and which parts will remain.”

Current predictions already suggest that global temperatures are expected to rise further – between 1.4° to 4.4°C by 2100. The size of the increase will depend on what measures countries and industry take to reduce greenhouse gas emissions.

An additional 30 centimetres of sea level rise is unavoidable regardless of emissions decisions, but the increase may be as much as one or two metres if emissions continue to be high and the WAIS continues to melt at an accelerating rate.

The expedition is scheduled to begin in November 2023 and is expected to continue into early 2024. It will be the first expedition of the SWAIS 2C programme. The second expedition will start in November 2024 and continue through 2025.

Logistical support for SWAIS 2C comes from Antarctica New Zealand (K862A-2324, K862A-2425) in collaboration with the United States Antarctic Program. Drilling is funded and supported by the International Continental Scientific Drilling Project (ICDP). The SWAIS2C Project Manager is GNS Science and the Drilling Services Provider is Te Herenga Waka—Victoria University of Wellington.

The project has received significant additional support from the Natural Environment Research Council, Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research, Federal Institute for Geosciences and Natural Resources, National Science Foundation (NSF-2035029, 2034719, 2034883, 2034990, 2035035, and 2035138), German Research Foundation (grants KU 4292/1-1, MU 3670/3-1, KL 3314/4-1), Istituto Nazionale di Geofisica e Vulcanologia, Korea Polar Research Institute, National Institute of Polar Research, Antarctic Science Platform (ANTA1801), Leibniz Institute for Applied Geophysics, AuScope, and the Australian and New Zealand IODP Consortium.