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).
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:
Rising sea levels and subsidence due to ground water pumping, coupled with increasing populations and economic growth in coastal cities, is expected to lead to a greater proportion of people living in low lying regions which will result in higher annual losses from flooding. A Nature Climate Change article, published recently, has estimated the average annual losses from flooding in the world’s largest coastal cities. The analysis shows annual loses from flooding could rise from about $6 billion per year in 2005 to over $1 trillion per year by 2050. Sea level rise and subsidence alone will increase annual losses to around $63 billion by 2050, even if investments are made to maintain flood probabilities at current levels. You can read more about the work here: http://link.springer.com/article/10.1007/s11069-012-0234-1.
The Permanent Service for Mean Sea Level’s (PSMSL), an important facility responsible for the collection, publication, analysis and interpretation of sea level data from the global network of tide gauges, are holding a workshop on the 28th to 29th Oct 2013 to celebrate their 80th anniversary. Several members of the iGlass team will be attending and presenting at that workshop.
See the following link for details – http://www.psmsl.org/about_us/news/2013/workshop_2013/