This week, the Glacier Mass Balance Intercomparison Exercise (GlaMBIE) has released a new report in Nature, assessing mass changes in the balance of the Earth’s glaciers from 2000 to 2023. The report shows that during this period, glaciers around the world have lost somewhere between 2% and 39% of their ice regionally and around 5% globally.
The team is co-led by Professor Michael Zemp (University of Zurich) and CPOM’s Associate Investigator: Ice Sheet Modelling and Satellite InSAR, Professor Noel Gourmelen (University of Edinburgh). It is coordinated by the World Glacier Monitoring Service (WGMS) at the University of Zurich, in collaboration with the University of Edinburgh and Earthwave Ltd.
There are an estimated 200,000 glaciers across the Earth and so monitoring them all individually is very challenging. That is why satellite observations are so important as they enable scientists to produce robust and accurate assessments of how much ice glaciers contain, and how rapidly they are melting. This is crucial if we are to protect our planet from the effects of climate change and to prepare for a warmer planet in the future.
2025 is the UN’s International Year of Glaciers’ Preservation, so never has there been a more pressing time to take notice of what’s happening in the cryosphere and strive to protect it.
You can read Professor Noel Gourmelen’s comments on GLaMBIE’s recent findings in this article from The Guardian, alongside comments from CPOM Director, Professor Andrew Shepherd.
The research is funded by the Science for Society element of ESA’s FutureEO programme, with additional support from the International Association for Cryospheric Sciences and various institutional partners
Environmental tipping points occur when warming temperatures lead to changes in the climate system which pass a threshold and become irreversible. Passing these points will lead to changes to sea level, ocean circulation and our weather, something world leaders need to plan for in advance. That’s why it’s vital to monitor for signs we are coming close to and passing these tipping points.
Combining observation and modelling expertise with innovative sensing systems, the programme aims to develop sensing systems for monitoring the Earth’s ice and oceans and place these systems in locations such as the Greenland Ice Sheet and the Subpolar Gyres (ocean circulation systems which sit under an area of constant low atmospheric pressure); both of which have been identified as crucial climate tipping points.
The programme will also look at developing improved models (computer simulations) to produce more robust and accurate predictions of these tipping points and the potential impact on the planet.
The programme is made up of 27 international teams of experts in climate science, maths, computer science, statistics, optics, photonics, and nuclear physics – bringing together this expertise to develop the best possible early warning system for these climate tipping points.
CPOM members are supporting three of these teams:
CryoWatch: Aims to progress the development of affordable, solar-powered, High Altitude Pseudo Satellites (HAPS), to be stationed in the stratosphere for persistent monitoring of polar regions. Led by Steve Tate (Voltitude), the team includes CPOM Co-Director of Science, Professor Mal McMillan.
OptimISM: A Next-Generation Framework for Ice Sheet Modelling. Led by Trystan Surawy-Stepney (University of Leeds), the team includes CPOM Principal Investigator: Land Ice Modelling, Dr Steph Cornford (University of Bristol).
PROMOTE: Progressing Earth System Modelling for Tipping Point Early Warning Systems. Led by Reinhard Schiemann (University of Reading and National Centre for Atmospheric Science), the team includes CPOM Principal Investigator: Land Ice Modelling, Dr Steph Cornford (University of Bristol).
It is said that Ernest Shackleton advertised ‘men wanted’ for ‘hazardous journey, small wages, bitter cold, long months of complete darkness, constant danger’ ahead of his 1914 Antarctic expedition which ended in the loss of his ship. Back then polar exploration and research was seen as an exclusively male occupation, even though women had been involved since as early as the 19th century. Women were often formally blocked from joining expeditions to the Arctic and Antarctic.
Times have certainly changed since then. During the last century intrepid and tenacious women led the way in shattering this ice ceiling. Fast forward more than a century after Shackleton’s infamous advert to 2025 and women scientists are participating in and leading field research projects across the cryosphere.
The UK Centre for Polar Observation and Modelling, brings together Earth Observation experts with modellers, to provide robust and accurate measurements of the Earth’s ice from the past and present, as well as projections for the future to help with world prepare for the changes a warming world might bring. Although we use satellite data in our work, Earth Observation often requires field-based observations to help verify satellite data, and so fieldwork is still an important piece of the puzzle when researching the polar regions, providing our scientists with wonderful opportunities to visit these incredible and rapidly changing environments.
DEFIANT (Drivers and Effects of Fluctuations in sea Ice in the ANTarctic) is a NERC project aimed at studying sea ice in the Southern Ocean and how it affects the wider climate system. CPOM’s Dr Inès Otosaka and Dr Isobel Lawrence and CPOM Director Professor Andrew Shepherd joined a fantastic team of scientists from BAS and DTU, to visit Antarctica to verify data collected on Antarctic sea ice by satellites.
Image credit: Professor Andrew Shepherd
Inès said (in this blog she wrote at the time) that ‘it was incredibly rewarding to see all the work that had been done over the months preceding the actual fieldwork come to fruition’. Although field work can be an exhausting experience, there was still time to enjoy the spectacular location with the team being ‘lucky enough to spot some penguins, seals, and even a pod of orcas.’
The team recorded this brilliant Iceworld podcast with BAS (British Antarctic Survey) – have a listen to their experiences on this incredible expedition.
Inès also joined Andrew Shepherd, PhD Researchers Amy Swiggs and Dr Anne Braakmann-Folgmann (former PhD Researcher) on the European Space Agency’s (ESA’s) Cryo2ice campaign to Greenland in 2022 where they collected ice cores, verified LiDAR measurements and collected snow depth measurements for snow density calculations. Amy wrote this blog about the fieldwork adventure, if you want to read more about this.
More recently in September 2024, Amy and Inès were also part of a CPOM team that visited Iceland to study proglacial lakes with a drone, alongside PhD Researcher Natasha Lee, CPOM Director for Knowledge Exchange Dr Sammie Buzzard, Andrew Shepherd, PhD Researcher, Nitin Ravinder and Data Scientist, Ben Palmer. We made this short film about this campaign, showing the team in action.
Image: CPOM PhD Researcher Natasha Lee, setting up a drone, on the Iceland Fieldwork campaign 2024.
Getting the opportunity to do fieldwork at an early career stage often draws people to polar science. For Dr Rosie Willatt (CPOM PI) the opportunity to visit Antarctica as a PhD student was a turning point in her career, and ultimately led to her becoming a polar scientist. You can hear more about how Rosie became a polar scientist in this video.
Sammie Buzzard, a glaciologist who started out studying maths, has been part of numerous fieldwork expeditions, including measuring glaciers in the Arctic during her PhD. She will soon be visiting the Antarctic in 2025.
She said “Although we are still far from gender equality within the polar sciences it’s fantastic to see opportunities becoming available to those of all genders that wouldn’t have been even during the earlier years of my lifetime”.
Image: CPOM’s Sammie Buzzard, preparing equipment on the Iceland Fieldwork Campaign, 2024.
These are just some of the examples of CPOM women scientists leading, and working on, these important fieldwork projects across the Arctic and Antarctica.
As we strive to understand these complex regions, how climate changes affect them and in turn how these changes will impact the rest of the planet in the years to come, it’s fantastic to see women scientists playing a vital role following the years of exclusion they experienced in previous centuries.
Greenland is a fascinating and beautiful country, with a population of more than 50,000 people. It has long been a key area of focus for polar scientists, due to the importance of observing and modelling of changes to the Greenland ice sheet. This huge expanse of ice, the second largest land ice mass in the world, is more than 2000km in length, 1000km wide and at its thickest point is over 3km thick.
And this ice sheet is melting.
Melting ice sheets directly contribute water to the oceans, leading to sea level rise. This influx of cooler water also affects the ocean circulation, with implications for global weather patterns. Accurately tracking melting of the Greenland and Antarctic ice sheets is essential to ensure people all over the world can prepare for the effects of climate change.
As ice sheets are so huge they are incredibly difficult to fully measure in person. Satellite measurements are the only ways we can accurately measure these vast areas.
CPOM has provided assessments of the amount of ice stored in the Greenland and Antarctic ice sheets since 2018, via the IMBIE Project (Ice Sheet Mass Balance Intercomparison Project) which uses three decades of satellite data to assess the ice sheets. You can read their most recent report in Earth System Science Data from 2023, which estimates ice losses from these regions since 1992.
Another recent study from December 2024, led by CPOM PhD Researcher, Nitin Ravinder, and published in Geophysical Research Letters, showed that the Greenland ice sheet lost 2347 km3 of ice during the period since 2010 – which has contributed roughly ‘the amount of water stored in Africa’s Lake Victoria’ to the Earth’s oceans. Here’s an animation from Planetary Visions based on this study showing these changes in the Greenland ice sheet.
As sea level rise will affect many millions of people around the world, as well as the numerous at-risk species in coastal habitats, it’s vital that Governments and international bodies are able to plan for this rise. Computer modelling (simulations) is the only way we can accurately predict how the ice sheets might behave in the future.
CPOM provides UK National Capability research in ice sheet modelling, developing the BISICLES model.
BISICLES is a numerical model (simulation) that works with high resolution simulations around the margins of ice sheets (the grounding line), where interactions between the ice sheet and the ocean and atmosphere are the most complex. This is particularly useful when looking at the Greenland ice sheet.
Scientists from CPOM recently worked on combining this system as the ice sheet component within the UKESM (The UK Earth System Model), allowing us to better explore and understand the interactions between the ice sheets and the global ocean and atmospheric circulations (and providing evidence for IPCC reporting).
BISICLES has also been integrated into large international projects such as ISMIP (Ice Sheet Model Intercomparison Project) to help project future changes to global sea levels, something that is particularly difficult to predict beyond the end of the century with one model alone.
The behaviour of the Greenland ice sheet is particularly difficult to predict, as over recent years we have seen points where melting has been more rapid than anticipated, but also points where it has been less than expected. We need to continually hone and improve computer simulations (or models) that can accurately predict how these ice sheets might behave in a rapidly warming planet to account for the complexity of the interactions between the ice sheets and the atmosphere in these regions.
Understanding this part of the world is vital for understanding how we might protect the rest of the Earth in the years to come. By combining expertise in land ice Earth observation with modelling simulations, like BISICLES, CPOM is continuing to increase the accuracy of future projections of sea level rise and weather changes, leading from the melting of the Greenland ice sheet.
