West Antarctic ice sheet melting: How the past can help to predict the future
Findings from a study are helping to narrow uncertainty around the future behaviour of the West Antarctic Ice Sheet and its role in future sea level rise.
The study found that parts of the West Antarctic Ice Sheet (WAIS) may have survived continuously for the last 1.4 million years, even during periods of temperature rise.
Despite a substantial amount of ice melt caused by warmer temperatures during this period, findings suggest that the ice sheet did not collapse entirely and therefore may have limited global sea level rise to 3.3 metres.
This data will help scientists to predict how the WAIS will react to global ocean and air temperature rises in the near future.
Overview of the Research
In a unique study, researchers used a chemical technology, known as cosmogenic nuclide dating to examine how levels of ice covering the land on the West Antarctic Ice Sheet had changed over hundreds of thousands of years.
Speaking to us about the research, Dr Hein outlined the project,
“The aim was to determine how much of the West Antarctic Ice Sheet melted during past warm periods in the Earth’s history, when temperatures were warmer than today and closer to the temperatures predicted for the end of the century”
- Despite substantial ice melt due to past warming, parts of the WAIS may have existed continuously for the last 1.4 million years.
- By understanding that the WAIS did not collapse entirely during warmer historical periods, this could have limited the ice sheet’s contribution to global sea level rise to 3.3 metres above present levels.
The WAIS contains enough ice to raise global seal levels by 5 metres if all of the ice melted, but the survival of smaller ice caps in West Antarctica during past warm periods suggests a smaller contribution. Our findings suggest this ice sheet has the potential to contribute up to 3.3 metres to future sea level rise.
Implications of the research
Understanding the behaviour of the WAIS during warmer periods in the past, is essential for expanding our understanding of how the ice sheet may respond in relation to global warming in the future. Understanding the answers to questions such as ‘Did the ice sheet completely disappear?’ or ‘Did it reduce in size, but remain intact?' are essential for understanding the most likely future trajectory of the ice sheet.
Speaking about future research plans, Dr Hein outlined the next steps for the team’s research,
“We are now trying to understand how fast the ice sheet has changed in the past. The aim is to understand the mechanisms and timescales over which the ice sheet has thinned and contributed to past sea level rise. By inference, we hope to better understand how the ice sheet might change in the future”.