CPOM contributed to the European State of the Climate 2020 report, an annual report compiled by the Copernicus Climate Change Service (C3S) and implemented by ECMWF on behalf of the European Commission. This year, we contributed to two sections: the ice sheets section as well as a new thematic section on the cryosphere as a whole.

The ice sheets are included in this report as a climate indicator, and we provided estimates of the Antarctic and Greenland Ice Sheets mass balance produced by IMBIE.

We also contributed to the cryosphere section which includes the ice sheets, mountain glaciers and sea ice and provides a broad overview of the cryosphere. It shows large changes in these three components, with the ice sheets losing a volume of ice equivalent to 10 times the volume of lake Garda, glaciers losing three times the volume of the European Alps during the past decade and sea ice losing an area 5 times the area of Spain between the 1980s and 2010s.

Here are the links to the sections of the report we contributed to:

https://climate.copernicus.eu/climate-indicators/cryosphere

https://climate.copernicus.eu/climate-indicators/ice-sheets

Figure 1. Components of the cryosphere. Based on Lemke et al. 2007. Credit: C3S/ECMWF

Figure 2. Changes over time in key cryosphere components: ice sheets, glaciers and sea ice. Data source: Ice sheets (IMBIE/ESA/NASA), glaciers (WGMS), sea ice extent (EUMETSAT OSI SAF), sea ice thickness (C3S). Credit: C3S/ECMWF/University of Leeds/WGMS/EUMETSAT OSI SAF/AWI.

The rate at which ice is disappearing across the planet is speeding up, according to new CPOM research. The findings also reveal that the Earth lost 28 trillion tonnes of ice between 1994 and 2017 equivalent to a sheet of ice 100 metres thick covering the whole of the UK.

The research is the first of its kind to carry out a survey of global ice loss using satellite data.

Article first published by University of Leeds

Scientists led by CPOM found that the rate of ice loss from the Earth has increased markedly within the past three decades, from 0.8 trillion tonnes per year in the 1990s to 1.3 trillion tonnes per year by 2017.

Ice melt across the globe raises sea levels, increases the risk of flooding to coastal communities, and threatens to wipe out natural habitats which wildlife depend on.

“The ice sheets are now following the worst-case climate warming scenarios.“

DR THOMAS SLATER, CENTRE FOR POLAR OBSERVATION AND MODELLING

The findings of the research team, which includes the University of Edinburgh, University College London and data science specialists Earthwave, are published in European Geosciences Union’s journal The Cryosphere.

Funded by the UK Natural Environment Research Council, the research shows that overall, there has been a 65% increase in the rate of ice loss over the 23-year survey. This has been mainly driven by steep rises in losses from the polar ice sheets in Antarctica and Greenland.

Lead author Dr Thomas Slater, a Research Fellow at Leeds’ Centre for Polar Observation and Modelling, said: “Although every region we studied lost ice, losses from the Antarctic and Greenland ice sheets have accelerated the most.”

“The ice sheets are now following the worst-case climate warming scenarios set out by the Intergovernmental Panel on Climate Change. Sea-level rise on this scale will have very serious impacts on coastal communities this century.”

Dr Slater said the study was the first of its kind to examine all the ice that is disappearing on Earth using satellite observations.

He added: “Over the past three decades there’s been a huge international effort to understand what’s happening to individual components in Earth’s ice system, revolutionised by satellites which allow us to routinely monitor the vast and inhospitable regions where ice can be found.

“Our study is the first to combine these efforts and look at all the ice that is being lost from the entire planet.”

The survey covers 215,000 mountain glaciers spread around the planet, the polar ice sheets in Greenland and Antarctica, the ice shelves floating around Antarctica, and sea ice drifting in the Arctic and Southern Oceans.

Rising atmospheric temperatures have been the main driver of the decline in Arctic sea ice and mountain glaciers across the globe, while rising ocean temperatures have increased the melting of the Antarctic ice sheet. For the Greenland ice sheet and Antarctic ice shelves, ice losses have been triggered by a combination of rising ocean and atmospheric temperatures.

During the survey period, every category lost ice, but the biggest losses were from Arctic Sea ice (7.6 trillion tonnes) and Antarctic ice shelves (6.5 trillion tonnes), both of which float on the polar oceans.

Dr Isobel Lawrence, a Research Fellow at Leeds’ Centre for Polar Observation and Modelling, said: “Sea ice loss doesn’t contribute directly to sea level rise but it does have an indirect influence. One of the key roles of Arctic sea ice is to reflect solar radiation back into space which helps keep the Arctic cool.

“As the sea ice shrinks, more solar energy is being absorbed by the oceans and atmosphere, causing the Arctic to warm faster than anywhere else on the planet.

“Not only is this speeding up sea ice melt, it’s also exacerbating the melting of glaciers and ice sheets which causes sea levels to rise.”

Half of all losses were from ice on land including 6.1 trillion tonnes from mountain glaciers, 3.8 trillion tonnes from the Greenland ice sheet, and 2.5 trillion tonnes from the Antarctic ice sheet. These losses have raised global sea levels by 35 millimetres.

It is estimated that for every centimetre of sea level rise, approximately a million people are in danger of being displaced from low-lying homelands.

Despite storing only 1% of the Earth’s total ice volume, glaciers have contributed to almost a quarter of the global ice losses over the study period, with all glacier regions around the world losing ice.

Report co-author and PhD researcher Inès Otosaka, also from Leeds’ Centre for Polar Observation and Modelling, said: “As well as contributing to global mean sea level rise, mountain glaciers are also critical as a freshwater resource for local communities.

“The retreat of glaciers around the world is therefore of crucial importance at both local and global scales.”

Just over half (58%) of the ice loss was from the northern hemisphere, and the remainder (42%) was from the southern hemisphere.

Further information

Earth’s ice imbalance is published in the European Geosciences Union’s journal The Cryosphere on 25 January 2021. Its DOI is 10.5194/tc-15-233-2021.

Image credits: CPOM; Ian Joughin channel created by the flow of melted ice in Greenland.

For further details or to arrange interviews, contact Ian Rosser in the University of Leeds press office via i.rosser@leeds.ac.uk 

The Government of the British Antarctic Territory has announced 28 new place names in the Territory today to commemorate the 200^th Anniversary of the discovery of Antarctica.

All of the names on the list were chosen to honour people who have made an exceptional contribution to furthering the understanding, protection and management of Antarctica over the last fifty years, and whose achievements warrant highlighting alongside those of the early explorers.

Included in the list of honours were two scientists, Professor Seymour Laxon and Dr Katherine Giles, who were integral to the development of the Centre for Polar Observation and Modelling and whose research still underpins much of our work today. Sadly, Professor Laxon and Dr Giles both died within three months of each other in 2013.

Professor Seymour Laxon (1963-2013)

Named for Professor Seymour Laxon, Director, Centre for Polar Observation and Modelling at University College London.

Professor Laxon was at the heart of all the achievements and successes of the Centre for Polar Observation and Modelling for two decades. His scientific breakthrough was to distinguish the ice surface from the water surface in satellite radar altimeter measurements of ice-covered oceans. This led to the first detailed map of the Arctic gravity field, revealing new tectonic features beneath the seafloor, and water circulation beneath the ice. His work also provided evidence that led to the development of the European Space Agency’s CryoSat mission.

Professor Laxon was an empirical scientist, and the integrity with which he treated his data was matched by the integrity and generosity with which he treated his colleagues and students, many of whom are now furthering our understanding of the Arctic through their own careers in the UK and overseas.

More detail about Professor Laxon’s life and work can be found in his obituary in The Guardian (February 2013).

Dr Katherine Giles (1978-2013)

Named for Dr Katharine Giles, Lecturer at University College London, a ground-breaking researcher into sea ice, ocean circulation and wind patterns who worked at University College London.

Dr Giles’s research focussed on sea ice, ocean circulation and wind patterns, and pioneered the use of satellite altimetry to measure the thickness of Arctic and Antarctic sea ice. After it had become clear that sea ice freeboard could be determined from satellite altimetry, Dr Giles performed some of the first ground-based experiments to show how the same observations could be accurately related to sea ice thickness.  This led her to undertake field campaigns to characterise radar penetration into sea ice, both in the Arctic and the Antarctic, and to identify that, in 2007, sea ice thinning accompanied the then record Arctic sea ice minimum extent.

Dr Giles was the first person to appreciate that altimeter observations between sea ice floes were more than just a stepping stone to measuring sea ice thickness: she demonstrated that they could also show how winds affected the newly-exposed Arctic Ocean.

She was also a passionate science communicator. The Dr Katharine Giles science blog prize is awarded by the Association of British Science Writers each year, founded following her tragically early death.

More detail can be found in Dr Giles’s obituary in the Times Higher Education (April 2013).

Renaud Island at the Antarctic Peninsula, 65.6924 South 65.9872 West

Also included in the list of honours is Professor Dame Jane Francis (Director of the British Antarctic Survey):

Professor Dame Jane Francis is the current and first female Director of the British Antarctic Survey (from 2013), and Chancellor at the University of Leeds (from 2018).

Dame Jane is a leading palaeobotanist and Professor of palaeoclimatology who specialises in the study of fossil plants, especially woods, and their use as tools for climate interpretation and information about past biodiversity in the polar regions. She is the first woman to chair a Working Group of Antarctic Treaty Consultative Meetings. She was awarded the Polar Medal in 2002 for outstanding contribution to British polar research and was appointed Dame Commander of the Order of St Michael and St George (DCMG) for services to polar science and diplomacy.

The full list of new place names can be found here.

More details about place naming and the Antarctic Place Names Committee can be found at: www.apc.antarctica.ac.uk

Scientists warn that if greenhouse gas emissions continue apace, Greenland and Antarctica’s ice sheets could together contribute more than 39cm to global sea level rise this century.

From University of Leeds press release, 17th September

The Ice Sheet Model Intercomparison Project (ISMIP6) is an international team, which includes a number of CPOM scientists, making predictions of ice sheet change under future climate scenarios to support the Intergovernmental Panel on Climate Change (IPCC).

ISMIP6 is led by NASA’s Goddard Space Flight Centre in Greenbelt, Maryland and brings together more than 60 ice, ocean and atmosphere scientists, including CPOM Director Andrew Shepherd (University of Leeds), CPOM Land Ice Lead Tony Payne (University of Bristol), CPOM staff researcher Victoria Lee (University of Bristol), and CPOM Associate Investigators Tamsin Edwards (King’s College London) and Isabel Nias (University of Liverpool).

Their latest findings, published this week in a special issue of the journal The Cryosphere, has estimated the impact Earth’s melting ice sheets could have on global sea levels by the end of the century.

The results reinforce projections made by the Intergovernmental Panel on Climate Change (IPCC) in their 2019 Special Report on Oceans and the Cryosphere.

The ISMIP6 team investigated two different scenarios the IPCC has set for future climate to predict sea level rise between 2015 and 2100: one with carbon emissions increasing rapidly and another with lower emissions.

Under the high emissions scenario, ice losses from Greenland cause an additional 9 cm of global sea level rise by 2100, while Antarctica causes an additional 30 cm over the same period.

Under the lower emissions scenario, Greenland’s ice loss would raise global sea level by about 3 cm by 2100, while Antarctic growth would lower sea level by 7.8 cm.

The greatest loss is from West Antarctica, responsible for up to 18 cm of sea level rise by 2100 in the warmest conditions.

The new results from ISMIP6 will inform the IPCC’s Sixth Assessment Report, scheduled for release in 2022.

“Unfortunately, it’s now clear that ice sheet losses have risen rapidly during our lifetime, and that this will continue if we don’t reduce our CO2 emissions.“

PROFESSOR ANDREW SHEPHERD

Professor Shepherd said: “Having three decades of satellite measurements has greatly improved our ability to simulate how Antarctica and Greenland respond to climate change. Unfortunately, it’s now clear that ice sheet losses have risen rapidly during our lifetime, and that this will continue if we don’t reduce our CO2 emissions.

“An extra 39 centimetres of sea level rise will cause huge disruption for our coastal communities, so we should view these predictions as a powerful early warning but now is the time to act.”

“One of the biggest uncertainties when it comes to how much sea level will rise in the future is how much the ice sheets will contribute,” said project leader and ice scientist Sophie Nowicki, now at the University at Buffalo, and formerly at NASA Goddard. “And how much the ice sheets contribute is really dependent on what the climate will do.”

“The strength of ISMIP6 was to bring together most of the ice sheet modelling groups around the world, and then connect with other communities of ocean and atmospheric modelers as well, to better understand what could happen to the ice sheets,” said Heiko Goelzer, a scientist from Utrecht University in the Netherlands, now at NORCE Norwegian Research Centre in Norway. Goelzer led the Greenland ice sheet ISMIP6 effort.

“The Amundsen Sea region in West Antarctica and Wilkes Land in East Antarctica are the two regions most sensitive to warming ocean temperatures and changing currents, and will continue to lose large amounts of ice,” said Helene Seroussi, an ice scientist at NASA’s Jet Propulsion Laboratory in Southern California.

Seroussi led the Antarctic ice sheet modelling in the ISMIP6 effort. “With these new results, we can focus our efforts in the correct direction and know what needs to be worked on to continue improving the projections.”

Further information: 

Top image: Credit: Ian Joughin Icebergs in Disko Bay, Greenland

For additional information contact press officer Anna Harrison a.harrison@leeds.ac.uk