climate change

This tag is associated with 7 posts

Probable unstable Pine Island Glacier retreat and sea level rise (new study)

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).

iGlass paper: A geological perspective on potential future sea-level rise

Sea-level versus carbon dioxide concentrations

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:


Introducing the Bristol team

Over the coming weeks we will introduce members of each team working on the iGlass consortium project. Today we will introduce the team from the School of Geographical Sciences at the University of Bristol.

Professor Tony Payne

Tony payneTony is a Professor of Glaciology in the School of Geographical Sciences and has a BSc in Environmental Science from the University of Stirling and a PhD in Geography from the University of Edinburgh. His PhD focussed on the numerical modelling of former ice sheets. Tony’s work today mainly centres on the development and application of numerical models of glacier and ice sheet flow in order to understand the evolution and dynamics of ice streams, and their effect on the stability of ice sheets. He has a particular interest in modelling the evolution of  Pine Island Glacier in West Antarctica.

Tony is a co-director of the Centre for Polar Observation and Modelling (CPOM) and was heavily involved in the recent European project ICE2SEA. Tony is also a lead author of the chapter on sea level change in the very recently published 5th IPCC report.

Dr Dan Lunt

Dan LuntDan Lunt is a Reader in Climate Science in the School of Geographical Sciences and has an MPhys from the University of Oxford and a PhD on modelling the dust cycle during the Last Glacial Maximum from the University of Reading. His research interests are broad but with a particular focus on climate – ice sheet interactions during the past and in the future. Dan aims to understand the mechanisms affecting past climate change using a model-data synthesis approach . This allows models to test hypotheses derived from interpretation of paleo-data while also providing the data community with information where useful data can be collected to test new hypotheses derived from models.

Dan is an  executive editor of the EGU journal, Geoscientific Model Development, which is primarily for model descriptions, from box models to GCMs. The philosophy behind the journal, is to improve rigour and traceability in climate modelling.  He is also involved in the iGlass related European Project Past4Future and is a contributing author of the chapter on past climate change in the 5th IPCC report.

Dr Joy Singarayer

joyJoy Singarayer is an Associate Professor of Palaeoclimatology in the Department of Meteorology at the University of Reading, having recently left the School of Geographical Sciences at the University of Bristol.  Her interests  are in Quaternary climate change and further back in time with an emphasis on understanding interactions between humans, land cover/use, and climate, prehistoric and present.

Apart from iGlass, Joy has been and is involved on the following projects: terrestrial methane cycling during Paleogene greenhouse climates (NERC), the Palaeoclimate Model Intercomparison Project (PMIP3) – LGM and Holocene terrestrial carbon fluxes and climate, climate change in the last glacial cycle (BBC) and cooling the climate with crops using biogeoengineering (DEFRA).

Dr Emma Stone

Emma StoneEmma Stone is a Research Associate in the School of Geographical Sciences. She has been at Bristol since 2006 where she completed a PhD (supervised by Dan Lunt and Paul Valdes) on the impact of vegetation feedbacks on the evolution of the Greenland ice sheet under future and past climates.  Previously Emma undertook an MEarthSci at the University of Bristol and an MSc in Applied Meteorology at the University of Reading.  She is particularly interested in understanding climate – ice sheet interactions during past warm periods.

As a researcher for the European Past4Future and iGlass projects, Emma uses climate models of various complexity to model the climate interactions during the Last Interglacial (LIG) period with an emphasis on model-data comparison and is currently working on developing a robust statistical methodology for model-data comparison.  The climate output will be used in conjunction with ice sheet modelling to predict sea-level change during the LIG.

Mr Matthew Whipple

Matt WhippleMatt Whipple is a PhD student in the  Geographical and Earth Science Departments and is supervised by Mark Siddall, Eric Wolff, Joy Singarayer and Dan Lunt. Before starting his PhD in 2011 Matt completed a BSc in Geophysics at the University of Liverpool. His PhD is funded by the iGlass project and is focussed on  investigating changes in the Antarctic ice sheet and contributions to sea level during the LIG, and other past warm periods.  He  uses several methodologies which involve combining output from glacio-isostatic adjustment models, climate models, and ice core isotope records.

Introducing the Cambridge team

Over the coming weeks we will introduce members of each team working on the iGlass consortium project. Today we will introduce the team from the British Antarctic Survey and the University of Cambridge.

Professor Eric Wolff

ImageEric Wolff is a Royal Society Research Professor in the Department of Earth Sciences at Cambridge University. After graduating as a chemist, he has studied ice cores from the Antarctic and Greenland for the past 30 years, using them to understand changing climate, as well as changing levels of pollution in remote areas. He also carries out research into the chemistry of the lower parts of the Antarctic atmosphere.

Until June 2013, he had worked at the British Antarctic Survey, leading their programme: “Chemistry and Past Climate”.  He chaired the science committee of the European Project for Ice Coring in Antarctica (EPICA), which produced 800,000 year records of climate from the Dome C (Antarctica) ice core and co-chairs the international initiative (IPICS) to coordinate future ice core research.  He has a strong interest in understanding the similarities, differences and consequences of the interglacials of the last 800,000 years.

Dr Rob Mulvaney

ImageRobert Mulvaney is the Science Leader of the Chemistry and Past Climate programme at the British Antarctic Survey.  He is an analytical chemist and palaeoclimatologist researching climate and environment of the past using chemistry and water isotope data from the analysis of ice cores.  Particularly interests include: the transition from the Last Glacial Maximum to the Holocene; millennial-scale climate change; location of chemical species in ice and diagenesis during burial; permanent gas isotopes trapped in ice as indicators of ice sheet response to climate; trace gases in ice and firn as evidence of anthropogenic changes to the atmosphere.

He is responsible for the UK ice core drilling operations in Antarctica with 18 field seasons experience.  He has worked further five seasons in the Arctic with multinational ice drilling projects, including the recent NEEM Deep Ice Core Drilling Project in Greenland.  Major successes include leading the ice core drilling projects to bedrock on Berkner Island (948m), James Ross Island (364m) and Fletcher Promontory (654m) in Antarctica. In Cambridge he leads a small team working in a modern analytical laboratory alongside a -25°C cold-room measuring the chemistry of ice cores.

Dr Katy Pol

ImageKaty Pol is a palaeoclimatologist at the British Antarctic Survey (BAS). Graduated in Mathematics and Physics, she completed her PhD at the Laboratoire des Sciences et du Climat et de l’Environnement (LSCE) in France in 2011, exploring the millennial to sub-millennial scale climate variability occurring during interglacial periods as recorded in the EPICA Dome C ice core. As part of her post-doc position at BAS, she is involved in the European Past4Future and UK iGLASS projects, combining her knowledge in interglacial climates and ice cores to investigate climatic changes (in sea ice extent, air temperatures or sea surface temperatures for instance) affecting polar regions during warm climatic periods.

Within the iGLASS project, she is in particular in charge of compiling data from different types of archives (e.g. marine sediments, terrestrial sediments or ice cores) to provide a clear view of what were the climatic states of polar regions during the past MIS 7, 9 and 11 interglacial periods. This aims to assess the response of polar ice-sheets to different climatic conditions, a key point when wanting to better understand the processes involved in sea level rise.

Dr Emilie Capron

Emilie Capron is a palaeoclimatologist. She joined the British Antarctic Survey in 2010 after completing a Ph.D at the Laboratoire des Sciences du Climat et de l’Environnement (France) where she analysed the air trapped in Antarctic and Greenland ice cores (air isotopic composition and methane concentration) in order to characterise the millennial-scale climatic variations during the last glacial inception and the early glacial period.

As part of the iGlass and the European Past4Future projects, she is working on a high latitude compilation of data on air and sea surface temperature changes (derived from marine sediment and ice cores) over the Last Interglacial period (115 000-130 000 years ago). This work deals in particular with the development of a common temporal framework between marine sediment and ice core records in order to provide a robust reconstruction of the sequence of climatic events over this time interval. This work will be used both as inputs for ice sheet modelling and targets for climate modelling of the Last Interglacial. In parallel to the iGlass project, Emilie analyses the ice (cation and anion content) and the trapped air (air isotopic composition) in Antarctic ice cores in order to provide constraints on the past evolution of Antarctic firns during large climatic transitions such as a deglaciation. She uses this information to help improving ice core chronologies.

Introducing the Durham team

Over the coming weeks we will introduce members of each team working on the iGlass consortium project. Today we will introduce the Durham University team.

Professor Antony Long
Antony holds a Chair in ImagePhysical Geography at Durham University. His research interests are Quaternary environmental change, especially past and future sea-level change and coastal evolution around Greenland and the North Atlantic.  He is particularly experienced in the use of isolation basins, estuarine and salt marsh sediments to reconstruct past sea level, and has, most notably, produced key relative sea-level datasets for Greenland, along with reconstructions of the former position of the ice sheet since deglaciation, constraining the ice load over a range of timescales.  Alongside this he has worked around the wider North Atlantic using salt marsh sediments to reconstruct sea level over decadal to millennial timescales; on buried estuarine sediments in the Irish Sea that record late glacial sea-level changes; and Holocene sea level and coastal evolution in England and north west Scotland.  Antony is Head of the Department of Geography at Durham University. He is currently a co-leader of PALSEA2, Editor in Chief of Journal of Quaternary Science, and sits on the Executive Committee of the Quaternary Research Association.

Dr Natasha Barlow
Natasha is a postdoctoral researcher on the iGlass project, having done her PhD at Durham.  Her interest is reconstructing Quaternary environments, and in particular relative sea-level change on both active and passive coasts.  Natasha is particularly experienced in the use of diatoms to quantitatively reconstruct relative sea-level change from coastal sediments, along with developing chronological frameworks.  This has led her to apply these techniques to salt marsh sediments from around the North Atlantic that act as ‘geological tide gauges’ for the last 2000 years (her previous postdoc) and reconstructions of land-level changes associated with great earthquakes in Alaska.  She also has some experience in glacial isostatic adjustment modeling and continues to work on questions regarding the impact of mass balance changes on sea level in Alaska, Iceland and South Georgia.

IPCC 5th Assessment WG1 summary

A summary for policy makers was released today. Itcover 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

Future flood losses in the world’s largest coastal cities

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.

November 2020

Blog Stats

  • 5,671 hits