GRAIL

GReenland ice sheet to Atlantic tipping points from Ice-sheet Loss

Start date
1 April, 2025
End date
31 March, 2030

GIANT (Greenland Ice sheet to AtlaNtic Tipping points from ice loss) is a pioneering science project that will test the potential for early warning of a critical climate tipping point: the potential disruption of North Atlantic ocean currents due to accelerating Greenland Ice Sheet melt.

This ambitious project brings together cutting-edge technology, field observations, computer modelling and artificial intelligence to monitor, understand and predict the input of Greenland meltwater and icebergs into the North Atlantic.


The scientific challenge

The North Atlantic Subpolar Gyre – a system of ocean currents crucial to regulating climate patterns across Europe and beyond – faces potential disruption as freshwater from the melting Greenland Ice Sheet enters the ocean system. This provides the potential for a tipping point (a critical threshold in the Earth system) that could lead to significant, rapid and potentially irreversible changes:

  • Significant changes to Europe’s climate and weather patterns
  • Increased flooding risks from global sea-level rise
  • Depletion of vital fish stocks around Greenland
  • Widespread disruption to the global ocean circulation system

Despite its importance, the mechanisms by which Greenland’s melting glaciers interact with the North Atlantic ocean remain chronically understudied, primarily due to the challenges of conducting research in ice-choked fjords.


Our approach

GIANT is using a multi-disciplinary approach to address these critical knowledge gaps:

  • Advanced observation systems: the team will deploy an innovative fleet of ocean, ice and airborne platforms in East and North-West Greenland to collect unprecedented data on glacier melting and iceberg calving processes
  • Physical modelling: these new observations will be incorporated into sophisticated computer models of glacier melting and calving to improve our understanding of these complex interactions
  • Artificial intelligence: AI technologies will be used to analyse complex data and improve predictions
  • Global climate modelling: GIANT will incorporate Greenland melting and calving processes into the UK Earth System Model to improve climate predictions
  • Early warning framework: a prototype early warning system will test the predictability of potential tipping-point thresholds in this region
A ship in a Greenlandic fjord with a snow-capped mountain behind
In 2026, some of the GIANT team will head to Greenland to conduct field research. BAS.

Impact

GIANT’s work extends far beyond research. By improving our understanding of how the Greenland Ice Sheet interacts with the North Atlantic, the project will:

  • Provide crucial data for climate adaptation planning
  • Support evidence-based policy interventions
  • Help safeguard communities and ecosystems that depend on the ocean
  • Contribute to global efforts to monitor and respond to climate tipping points


Our team

Supported by the ARIA Forecasting Tipping Points progamme, GIANT will address one of the most urgent challenges in climate science by bringing together a diverse international team of glaciologists, oceanographers, climate modellers, AI specialists and policy experts from:

  • British Antarctic Survey
  • Cambridge University
  • Cornell University
  • Danish Meteorological Institute
  • Edinburgh University
  • Leeds University
  • National Oceanography Centre
  • Oregon State University
  • Reading University
  • Scottish Association for Marine Science
  • St. Andrews University
  • Stirling University
  • Technical University of Denmark
  • The Alan Turing Institute

This ambitious project brings together cutting-edge technology, field observations, modelling and international expertise to monitor, understand and predict one of the most consequential climate system interactions on our planet. The results will feed into UK Earth System Model and be used to develop a prototype Early Warning System.

  1. GIANT will make new observations at Petermann and Kangerlussuaq glaciers, which drain the North-West and Eastern Greenland Ice Sheet respectively. These glaciers represent the two main ice-ocean interaction types in Greenland  – a floating ice shelf and a vertical melting glacier face.
Map
The Petermann and Kangerlussuaq glaciers were identified as prime targets in a community paper on Greenland fjord/glacier observation, which this image is taken from (Straneo et al., 2019).

 

2. We will develop and deploy a range of advanced sensors and observing platforms designed to overcome the challenges of these hard-to-access environments. In 2026, we will conduct a major research cruise to Kangerlussuaq Fjord in East Greenland, and use hot-water drilling technology to access the ocean beneath Petermann Glacier’s floating ice tongue in North-West Greenland.

Diagram
Melting and calving of Greenland glaciers involves a set of inter-related physical processes that are currently poorly sampled due to the difficulty in accessing the ice-choked fjords and heavily-damaged glacier surface.

 

3. These field observations will be used to constrain new physical process models of each component of the melting and calving processes. The resulting data  will then be used to train   sophisticated climate models and AI emulators to improve predictive capabilities.

Diagram, shape
Schematic of the GIANT aims and outcomes

 

Why study this region?

The stability of Atlantic Ocean circulation under increasing greenhouse gases presents a critical concern due to its potential to trigger large, abrupt changes in European and global climate. A central question is whether open ocean convection in the North Atlantic Subpolar Gyre can be sustained as sea surface freshening increases.

In the future, freshwater input into the North Atlantic could come from multiple sources: rivers, sea ice, precipitation or ice loss from the Greenland Ice Sheet. Among these, the Greenland freshwater source is particularly concerning as its:

  • growing at an accelerating rate
  • subject to significant uncertainty in projections
  • holds potential for abrupt change in the future

Greenland ice loss occurs through two primary mechanisms: increased surface melting and glacier discharge. Surface melting processes are relatively well understood and successfully incorporated into current models. Changes in ice discharge, however, remain far less well constrained.

Ice discharge is triggered at the edges of glaciers – or glacier termini – through complex processes occurring in the more than 200 deep, narrow fjords surrounding Greenland. Melting is controlled by changing fjord ocean conditions and by the injection of subglacial meltwater from beneath glaciers. Calving and fjord conditions are controlled by melting, iceberg mélange (the mixture of sea ice, icebergs, and brash ice that forms at the margin of a glacier calving in a fjord) and the unique geometry of the fjord.

Despite their critical importance, these physicals of fjord melting and calving are completely absent from current climate models – representing a significant gap in our ability to predict future climate scenarios.

 

RRS Sir David Attenborough

The RRS Sir David Attenborough, commissioned by NERC, built by Cammell Laird for operation by British Antarctic Survey, is one of the most advanced polar research vessels in the world.