Summary of the impact

The Research School of Earth Sciences (RSES) at ANU is leading global efforts to tackle one of today’s biggest challenges: as greenhouse gas emissions continue to drive climate change, where and by how much will sea level rise? Rising seas threaten coastlines, economies, and displace millions. More than $226 billion (2008 replacement value) in Australian infrastructure assets (commercial, industrial, road, rail and residential) are potentially exposed to inundation and erosion hazard for a sea-level rise of 1.1 m (DCCEE, 2011). Globally, 230 million people around the planet live in regions that are projected to be underwater by 2100, many of them in the Asia-Pacific regions neighbouring Australia. There is therefore an urgent need to predict future sea-level rise to prepare protective infrastructure and mitigate impacts on society.

RSES combines world-class expertise in paleoclimate reconstructions, past ice-sheet dynamics, ocean-ice interactions, and glacial isostatic adjustment (GIA) modelling to improve sea-level forecasts. Using satellite data and cutting-edge tools, RSES captures the complex interplay between oceans, ice sheets, and Earth’s interior. Our researchers have helped deliver international climate assessments with policy-relevant outcomes for world governments, informed Australian parliamentary committees and, via strategic partnerships with government (e.g. Geosciences Australia; DCEEW), are poised to guide regional efforts to limit the socio-economic risks of rising seas.

Underpinning research

As greenhouse gas emissions drive climate change, the resulting sea-level rise is poised to reshape coastlines and communities across the Asia-Pacific and beyond. The stakes are high: by the end of this century, under a high emissions scenario, sea levels are expected to rise by an average of 77 cm above 1994-2014 levels, and even worse scenarios can’t be ruled out, leading to catastrophic flooding, economic losses, and widespread displacement (IPCC, 2021). With the Australian economy potentially facing up to $1.1 billion in annual costs due to coastal inundation (Deloitte, 2021; 2024), understanding and predicting sea-level changes is not just an academic pursuit — it is a global imperative.

RSES is uniquely equipped to undertake this endeavour, blending cutting-edge research with a comprehensive, interdisciplinary approach. RSES’s world-leading expertise is underpinned by decades of fundamental research across the full spectrum of past, present, and future sea-level science:

1. Unlocking the past: RSES researchers reconstruct ancient sea levels and climate shifts using fossil corals, marine sediments, and geological records, offering a window into how quickly and by how much sea levels have responded to natural climate cycles including past warm climates (e.g. Hibbert et al. 2016; Stokes et al., 2022; Richards et al. 2023). These insights set essential bounds for ice-sheet behaviour and are used to calibrate the models that predict future sea level rise.
2. Mapping ice-sheet behaviour: Through field geology and advanced modelling, RSES traces past ice sheet extents and paleo-shorelines, revealing patterns of collapse and resilience that are critical to understanding future risks (Hollyday et al. 2024).
3. Modelling Earth’s dynamic response: Glacial Isostatic Adjustment (GIA) — Earth’s response to the redistribution of ice and ocean masses — is central to predicting sea-level change. RSES pioneered models for GIA that match observed past sea-level changes (e.g. Lambeck and Chappell, 2001). The school also leads global research efforts to reveal the structure of Earth’s interior (e.g. Kennett, 2013), a fundamental input on any model of GIA, placing us at the forefront of this complex science.
4. Tracking today’s changes: Leveraging satellite data from the last 20–30 years, RSES monitors real-time variations in ice-sheet mass and sea levels, capturing the urgent pace of ongoing changes and identifying regions of concern for ice loss (McGirr et al. 2024).
5. Simulating future scenarios: RSES’s state-of-the-art data-driven modelling tools integrate ocean-ice interactions (Morrison et al. 2020), ice-sheet dynamics and GIA (Lambeck and Chappell, 2001; Scott et al. 2024). This infrastructure enables forecasts that are as accurate as they are impactful, ready to guide global mitigation strategies (https://gadopt.org/).

RSES is globally unique in having collective expertise in all aspects of these issues. By harnessing this interdisciplinary strength, directly influencing the Intergovernmental Panel on Climate Change (IPCC) and Australia’s National research priorities and partnering with government (e.g. collaborations with Geoscience Australia), RSES is not only advancing our understanding of sea-level rise, but also positioning itself as a global leader capable of confronting one of the century’s most urgent challenges of helping nations prepare for what lies ahead.

References to the research

• Lambeck, K. & J. Chappell, Sea level change through the last glacial cycle, Science, 292, 679-686, 2001.
• Hollyday, A., Raymo, M.E., Austermann, J., Richards, F., Hoggard, M. and Rovere, A., 2024. Pliocene shorelines and the epeirogenic motion of continental margins: A target dataset for dynamic topography models. EGUsphere, 2024, pp.1-36.
• Stokes, C.R., N.J. Abram et al, 2022, Response of the East Antarctic ice sheet to past and future climate change, Nature, https://www.nature.com/articles/s41586-022-04946-0
• McGirr, R., P. Tregoning, A. Purcell and H. McQueen, Significant local sea level variations caused by continental hydrology signals, Geophysical Research Letters, https://doi.org/10.1029/2024GL108394, 2024.
• Rohling, E., G.L. Foster, K.M. Grant, G. Marino, A.P. Roberts, M.E. Tamisiea and F. Williams, Sea-level and deep-sea-temperature variability over the past 5.3 million years, Nature, https://www.nature.com/articles/nature13230, 2014.
• A. K. Morrison, A. McC. Hogg, M. H. England, and P. Spence, Warm circumpolar deep water transport toward Antarctica driven by local dense water export in Canyons. Scientific Advances, 6, eaav2516, 2020.
• Hibbert et al., 2016, Coral indicators of past sea-level change: a global repository of U-series dated benchmarks, Quaternary Science Reviews.
• DCCEE 2011. Climate change risks to coastal buildings and infrastructure. A supplement to the first pass national assessment. Department of Climate Change and Energy Efficiency, Canberra. https://www.dcceew.gov.au/sites/default/files/documents/risks-coastal-buildings.pdf
• SoE Report 2021, State of the Environment Report, Department of Climate Change, Energy Efficiency and Water, Canberra. https://www.dcceew.gov.au/science-research/soe
• Richards, F.D., S.L. Coulson, M.J. Hoggard, J. Austermann, B. Dyer, & J.X. Mitrovica (2023). Geodynamically corrected Pliocene shoreline elevations in Australia consistent with mid-range projections of Antarctic ice loss, Science Advances, 9, eadg3035.
• Kennett, B.L., Fichtner, A., Fishwick, S. and Yoshizawa, K., 2013. Australian seismological reference model (AuSREM): mantle component. Geophysical Journal International, 192, pp.871-887.

Key prizes, awards and appointments

• Malcolm Macintosh Prize, Physical Scientist of the Year (Dr Morrison, 2022).
• Maurice Ewing Medal, American Geophysical Union (Prof. Rohling, 2021).
• Highly cited author award (Prof. Rohling, 2019).
• Prime Minister’s Prize for Science (Prof. Lambeck, 2018).
• Balzan Prize (Prof. Lambeck, 2012).
• Order of Australia, (Prof. Lambeck, 2009).
• President, Australian Academy of Science (Prof. Lambeck, 2006-2010).

Key research grants that enabled this research

• King et al., The Australian Centre for Excellence in Antarctic Science, ARC Special Research Initiative,
  $25M, 2020-2026.
• Davies, D. R., S. Ghelichkhan, M. J. Hoggard, A. Gibson, W. Scott and S. C. Kramer. CoastRI GIA Modelling, via G-ADOPT, AuScope, $1.4M, 2023-2026.
• McGirr, R. and Tregoning, P., GRACE-FO analysis, Geoscience Australia contract, 2023-2025, $150K.
• Tregoning, P., McGirr, R., Han, S.-C., Yeo, I-Y, Khaki, M and McCullough, C, Tracking flood waters over Australia using space gravity data, ARC Discovery, 2024-2026, $510K.
• Tregoning, P., McQueen, H., Allgeyer, S, Analysis of GRACE-FO space gravity data, Geoscience Australia contract, $50K.
• Tregoning, P., McClusky, S.C and Bettadpur, S., GRACE Follow-On: Validation of measurements and initial results, ARC Discovery, 2019-2022, $490K.
• Davies, D. R., S. Ghelichkhan, The Geoscientific Adjoint Optimisation Platform (G-ADOPT), Cross NCRIS platform grant (ARDC, AuScope, NCI, Geosciences Australia), $1.1M, 2020-2023.
• Tregoning, P., McClusky, S., McQueen, H & Purcell, A., Marine and coastal climate services for extremes information (NESP 5.8), DCCEEW, 2019-2020, $260K.
• England, M. H., Hogg, A. McC, Morrison, A. K., Spence, P., Griffies, S. M., Risks of rapid ocean warming at the Antarctic continental margin, ARC DP, 2019-2024, $618k.
• Hoggard, M.J. & Ghelichkhan, S. Next generation sea-level modelling, Geoscience Australia collaborative agreement, 2022-2025, $150k.
• Latychev, K., Hoggard, M.J. & Czarnota, K. Simulating Australian sea-level change in SEAKON, Geoscience Australia collaborative agreement, 2022, $100k.
• Hoggard, M.J., Ghelichkhan, S. & Scott, W. Next generation forecasts of 21st century ground motion and sea-level rise across the Indo-Pacific region driven by global climate change, NCMAS and ANUMAS schemes, 2022-2025, 11.2 MSU (equivalent to ~$446k in-kind).

Details of the impact

At the forefront of global sea level research, RSES plays a pivotal role in shaping international climate policy and advancing scientific frontiers.

Driving IPCC Impact

RSES researchers are integral to the Intergovernmental Panel on Climate Change (IPCC), with academics contributing to the 6th Assessment Cycle and leading the landmark Special Report on The Ocean and Cryosphere in a Changing Climate. Our scientists negotiated critical policy-relevant presentation of sea level predictions requested by governments, achieving consensus among representatives from 195 nations. With RSES scholars nominated by the Australian government and selected by the IPCC for the upcoming 7th Assessment Cycle, our influence on global climate policy remains profound.

Revolutionizing Global Ice Mass Data

RSES hosts the only non-US members of NASA’s GRACE Follow-On mission team, which monitors polar ice sheet mass loss and ocean mass changes. By validating experimental data streams and pioneering new analysis methods, we’ve redefined how mission data products are created - shaping the tools used by scientists worldwide.

Transforming Scientific Understanding Beyond the Geosciences

Our work on Earth’s response to ice sheet loading/unloading has revolutionized diverse fields:

• Human Evolution: Demonstrating how lowered sea levels enabled ancient migrations across oceans (Lambeck et al., 2011).
• Astrophysics: Providing critical corrections for satellite orbits, Moon-Earth dynamics, and ancient eclipse studies (Ghelichkhan et al. 2021).

National Partnerships & Policy Impact

Collaborating with Geoscience Australia, we deliver cutting-edge analyses of space gravity data and forecast coastal inundation risks for Australia and Pacific Island nations. Our expertise supports Geoscience Australia’s Coastal Hazards Program, designed to identify future risks to Australian and neighbouring country communities, and informs Antarctic science initiatives via the Australian Centre of Excellence in Antarctic Science (ACEAS).

In policy, RSES has briefed federal politicians, testified before Senate committees, and shaped national discourse on climate and sea level - recorded in parliamentary Hansard. Our influence extends to shaping Australia’s National Science and Research Priorities, ensuring sea level rise remains a top research focus in Australia for decades.

Antarctic Leadership

As a leader in Australia’s Antarctic Science Program, RSES helped craft the nation’s decadal science strategy, emphasizing the urgency of sea level research. Our contributions drive Australia’s response to climate tipping points, extreme events, and shifting weather patterns.

Why It Matters

Sea level rise is Australia’s highest national science priority for Antarctic and Southern Ocean research—and RSES is at the helm. From transforming global datasets to influencing international policy, our work shapes the science, strategy, and solutions needed to tackle one of humanity’s greatest challenges.

Where next

The Future of RSES Sea Level Research: Tackling Fundamental Challenges

To achieve precise predictions of future sea levels, RSES is addressing critical scientific questions:

• What is Earth’s 3D constitution?

  Earth’s material properties vary spatially, yet glacial isostatic adjustment (GIA) models have only recently begun to account for these variations. Revealing Earth’s 3-D structure, using geophysical techniques such as seismic imaging, and incorporating these into GIA models, is essential for accurate future sea level predictions and is a key goal of RSES future modelling endeavours.

• What’s happening to polar ice sheets?

  Satellite measurements provide insights into present-day melting of the Antarctic and Greenland Ice Sheets but are contaminated by current lack of accurate knowledge of ongoing glacial isostatic adjustment.
  Improvements in the former will permit more accurate quantification of present-day contributions to global sea level rise from the polar ice sheets.

• Which Antarctic regions are near tipping points?

  The historical sea level record shows that very large (i.e. 1-5 m) increases in global sea level can occur over short time periods (i.e. < 200-300 years). We need to improve our understanding of ice collapse vulnerabilities and process, and their incorporation into Earth System Models to improve predictability and inform climate change mitigation targets.

• What’s the outlook for Australia and Pacific Island nations?

  Combining accurate ice mass balance data, advanced GIA models, and Earth System simulations will enable precise regional sea level predictions.

Impact will occur in fields of coastal development (infrastructure planning, land zoning impacts on property prices and insurance viability), defence (sea level rise impacts on national security of Australia and neighbouring countries) and even the migration of populations as their island homes become unliveable due to rising sea levels.

Deliverables Driving Progress

• Ground Motion Monitoring: Building a database of vertical land movement along the Australian coastline (funding sought via NCRIS).
• Sustained Antarctic Science Funding: Shaping the Australian Academy of Science’s advocacy for Antarctic research.
• Antarctic Tipping Points: Addressing risks of catastrophic sea level rise from West and East Antarctic ice sheet collapse, unlocking up to 7.5+ meters of global sea level rise.
• Climate Modelling Leadership: Selecting an advanced ice sheet model for Australia’s climate simulator (ACCESS-NRI); developing data-driven GIA models; and coupling GIA and ice sheet models, revolutionizing national capabilities in sea level prediction.

Global Impact

Our research will inform infrastructure planning, insurance, defence strategies (sea level rise impacts on national security of Australia and neighbouring countries), and population migration as rising seas reshape coastlines.

Achieving These Goals

Achieving these deliverables requires combining satellite monitoring, Antarctic field observations, ocean/ice circulation modelling and improving the modelling of ice/Earth interface for GIA. We are:

• Monitoring Antarctic mass loss, in conjunction with Geoscience Australia and NASA’s GRACE Follow-On Science Team.
• Linking seismic imaging with laboratory experiments to understand Earth’s physical properties.
• Developing GIA models with 3-D viscosity variations, informed by novel insights into Earth’s physical properties, that can formally link to observational data from across the geosciences.
• Modelling ocean-ice interactions in a warming world.

Our work will directly influence Australia’s National Science and Research Priorities, shaping climate resilience from 2025 onwards. By embedding recent advances into predictive models, RSES will continue to lead the way in addressing the most pressing challenges of sea level rise.

Demonstrated alignment with school, university and national priorities

At the heart of RSES’s commitment to tackling key global challenges, sea level research stands as a cornerstone of the “Climate and Ocean” focus area. This work brings together experts in Climate and Ocean Geoscience and Geophysics, aligning with ANU’s mission to drive global environmental sustainability through cutting-edge analysis and knowledge provision on sea level predictions.

A Lifeline for the Pacific and Beyond

RSES’s efforts resonate with ANU’s goal to collaborate with Asian and Pacific neighbours, addressing the emerging regional issues posed by rising sea levels. This pressing challenge threatens the very existence of Pacific Island nations, highlighting the urgent need for actionable science and solutions.

National Research Priorities in Action

Our sea level research directly supports Australia’s National Research Priorities, driving innovation and resilience in the face of climate change:

Protecting and Restoring Australia’s Environment

• Advancing the collection, interpretation, and sharing of environmental data to inform critical decisions.
• Analyzing past and future climate conditions in Australia, its coasts, neighbouring regions, and Antarctica - unveiling tipping points, shifting weather patterns, extreme events, and sea level rise.
• Developing state-of-the-art tools and techniques for environmental data analysis.

Building a Secure and Resilient Nation

• Enhancing cost-effective, climate-resilient infrastructure, ensuring communities can withstand natural disasters and climate impacts.
• Predicting and responding to biosecurity threats and natural disasters through robust scientific insights.

Why This Matters

RSES’s sea level research not only addresses immediate challenges but also builds a foundation for long-term resilience, protecting communities and ecosystems across Australia, the Pacific, and beyond. By aligning with national and regional priorities, we’re helping to secure a sustainable and resilient future for generations to come.