Why not have a look at our new short videos from the iGlass researchers explaining what they do…
Find the films under the video tab
Prof. Tony Payne (Bristol University) contributing author on recent study (Favier et al., 2014. Nature Climate Change doi:10.1038/nclimate2094) showing that Pine Island Glacier’s grounding line is probably engaged in an unstable 40 km retreat. Using ‘state-of-the-art’ ice-sheet modelling, the team demonstrated that the dynamic contribution to sea level rise will remain at a significantly higher level compared with conditions prior to the retreat (equivalent to 3.5–10 mm eustatic sea-level rise over the 20 years).
Following the publication of their recent paper in Scientific Reports, Professor Eelco Rohling was interviewed by Australia’s 9News programme and Dr Ivan Haigh was interviewed by local radio station Wave102. The recent paper looked at modern sea level rise within the context of information from the geological record. They conclude that the present rate is rea level rise is rising rapidly by natural standards. Present sea level rise is currently (just) within natural limits but continued monitoring is needed to determine if and when it goes outside of these limits (and our current understanding) with potentially severe consequences.
You can hear Ivan’s interview here and watch Eelco’s interview
CL5.11: Sea level in interglacials as a constraint on future changes
iGlass will be running a session at EGU2014. We would like to strongly encourage you to submit an abstract to our session (deadline for abstract submission: 16th January 2014)
Session details: Sea level appears to have been at a higher level than today in at least some of the recent interglacial periods. In this session, we aim to understand how the respective climate histories led to those higher sea levels, and assess how this information can help us constrain projections for future sea level over a range of timescales. Contributions will be welcome that:
The session will include work from the UK project iGLASS, but other contributions addressing the above questions will be equally welcome.
Convenors: Eric Wolff, Fiona Hibbert and Dan Lunt
A new paper by iGlass members suggest modern sea level changes is rapid by past interglacial standards (Rohling et al., 2013 Scientific Reports).
“During ice-age cycles, continental ice volume kept pace with slow, multi-millennial scale, changes in climate forcing. Today, rapid greenhouse gas (GHG) increases have outpaced ice-volume responses, likely committing us to > 9 m of long-term sea-level rise (SLR). We portray a context of naturally precedented SLR from geological evidence, for comparison with historical observations and future projections. This context supports SLR of up to 0.9 (1.8) m by 2100 and 2.7 (5.0) m by 2200, relative to 2000, at 68% (95%) probability.”
The research led by Prof. Eelco Rohling and Dr Ivan Haigh suggests that comparison of present changes in sea level to the natural context outlined in this paper, may be used to identify if and when sea-level response becomes ‘special’ (i.e., unprecedented during geological interglacials).
Professor Rohling concludes: “For the first time, we can see that the modern sea-level rise is quite fast by natural standards. Based on our natural background pattern, only about half the observed sea-level rise would be expected. Although fast, the observed rise still is (just) within the ‘natural range’. While we are within this range, our current understanding of ice-mass loss is adequate. Continued monitoring of future sea-level rise will show if and when it goes outside the natural range. If that happens, then this means that our current understanding falls short, potentially with severe consequences.”
Australia’s 9 News interview with Prof. Eelco Rohling:
UK Wave 102 radio interview with Dr Ivan Haigh:
A summary for policy makers was released today. It includes is a clear statement that humans have influenced climate system.
“As the ocean warms, and glaciers and ice sheets reduce, global mean sea level will continue to rise, but at a faster rate than we have experienced over the past 40 years,” said Co-Chair Qin Dahe.
From the summary of thesea level chapter: “There is very high confidence that maximum global mean sea level during the last interglacial period 129,000 to 116,000 years ago) was, for several thousand years, at least 5 m higher than present and high confidence that it did not exceed 10 m above present. During the last interglacial period, the Greenland ice sheet very likely contributed between 1.4 and 4.3 m to the higher global mean sea level, implying with medium confidence an additional contribution from the Antarctic ice sheet. This change in sea level occurred in the context of different orbital forcing and with high-latitude surface temperature, averaged over several thousand years, at least 2°C warmer than present (high confidence).” (Approved summary for policy makers WGI AR5-SPM_Approved27Sep2013)
Further information: link to the IPCC
Last night a couple of iGlass members attended the Geological Society of London Special Lecture given by Prof. Kurt Lambeck. Prof. Lambeck was presented with the Society’s highest award, the Wollaston Medal and gave an overview of his research career that spans more than 50 years. We were treated to an overview of his work with a focus on: what we have learnt about past ice sheets from geophysical inversion models, the mantle’s response to loading on timescales of thousands of years and lessons from the past that may be relevent in understanding present (and future) sea level change.