Dr James Lea, Dr Stephen Brough, Professor Douglas Mair, Dr Isabel Nias, and Mr Connor Shiggins ARC0007
Written evidence submitted by Dr James Lea, Dr Stephen Brough, Professor Douglas Mair, Dr Isabel Nias, and Mr Connor Shiggins, University of Liverpool
The following is a written submission to the Polar Research Sub-Committee of the Environmental Audit Committee from glaciologists at the University of Liverpool. This is provided to highlight: the science relating to the current and future state of Arctic glacial ice; environmental risks arising from this; and views on the future of UK Arctic science.
It comprises of:
- A brief discussion of the causes and magnitude of ice loss in the Arctic, set against the context of Arctic climate warming
- Discussion of glacier impacts on future economic activity in Greenland and implications for achieving net zero
- The opinions of the authors on how UK Arctic science can be strengthened as the region is set to continue to undergo unprecedented environmental, social and economic change.
The authors are happy to elaborate on any of the topics raised in this submission.
Section 1: Effects of Climate Change on Arctic Glacier Ice Masses
The Arctic region is warming four times faster than the rest of the planet[1], which is having dramatic effects on the Arctic’s land-based ice (i.e. glaciers, Canadian and Russian ice caps, and the Greenland Ice Sheet). This is illustrated by the strong multidecadal warming trends that are being experienced across the Arctic where parts of the Arctic are warming at more than 2°C per decade (Figure 1, left), in addition to the extremes occurring in individual years that are occurring over both glaciated and non-glaciated Arctic regions (Figure 1, right).
Figure 1 - Decadal warming rate of mean annual air temperature for the period 1991-2020 (left); and comparison of 2022 mean annual air temperature to the average annual air temperature for the period 1991-2020. Maps processed for this evidence submission from ERA5-Land Hourly data.
The survival of glaciers broadly depends on the volume of snowfall equaling or exceeding the amount of ice lost through surface melting and iceberg calving. Changes to both long term climate conditions and extreme events (from daily to annual timescales) have potentially significant implications for the future health of the Arctic’s glacial ice, sea level change, marine and terrestrial biology, ocean circulation, weather and the future safety of shipping and infrastructure as human activity in the Arctic increases.
This section provides a brief summary of ice loss in the Arctic via its two primary mechanisms, namely: iceberg calving/submarine melting from marine terminating glaciers; and where surface meltwater runoff exceeds snowfall.
Ice loss from marine terminating glaciers: The Greenland Ice Sheet is currently the largest global contributor to sea level rise, losing ice at a rate of 273 gigatonnes per year (equivalent to increasing global average sea level by 0.75 mm per year)[2]. Approximately 50% of this mass loss has been from Greenland’s 273 marine terminating glaciers, with these ice margins retreating by a total of 499.8 km between 2000 and 2019 (average: 1.8 km retreat per glacier; maximum glacier retreat: 27.9 km)[3]. Across the wider Arctic, glacier ice loss has also been substantial, with the 1496 non-Greenland marine terminating glaciers contributing a total of 2.1±0.22 mm to global sea level between 2000 and 2020[4]. While projections of sea level change during the 21st century for non-ice sheet glaciers is currently lacking, Greenland alone is already committed to contribute between 17.5 to 52.4 mm of global sea level rise by 2100 without any further warming[5]. Continued warming (that is anticipated) is likely to increase these numbers, with concomitant impacts on UK and international flood defences, ports and other coastal infrastructure/property.
Loss of ice from marine terminating glaciers is exacerbated by rapid warming of air temperatures in the pan-Arctic region in the last 30 years (Figure 1). The meltwater generated by these higher temperatures is largely transported through the glacier underneath the ice and exits at the iceberg calving front. As the meltwater is discharged into the fjord it has the following effects:
● Iceberg calving activity is enhanced as the meltwater drives circulation of warm ocean water towards the glacier, increasing ice loss through both submarine melting and iceberg calving
● Sediment transported from underneath the glacier delivers nutrients to the ocean, impacting organisms from the microscopic level to enigmatic species such as polar bears and walrus
● Retreat of glaciers change the location of foraging grounds, with potential impacts on entire ecosystems, shifting populations of fish, birds, and animals.
These impacts are also being strongly felt around the Greenland ice sheet, with ocean temperature warming combining with greater meltwater production to drive substantial glacier retreat[6],[7],[8]. Marine terminating glacier environments are crucial to sustaining high biological productivity (with concomitant impacts on fishing grounds)[9], though as glaciers retreat into shallower water the changes in nutrient fluxes will likely decrease overall productivity[10].
Ongoing uncertainty regarding how to incorporate calving processes into numerical models of future glacier change is substantial, with calving estimated to account for anything from 30-70% of total ice loss from Greenland by 2100[11]. Furthermore, projections of iceberg loss from Greenland do not currently provide information regarding how or if iceberg size may change in the future. This unknown has ramifications for future shipping safety through Arctic waters, especially with the anticipated opening of the Northwest Passage through the territorial waters of Greenland, Canada and the USA. Given the currently sparsely populated nature of these areas and relative lack of rapid response search, rescue and environmental emergency infrastructure, the future risks associated with iceberg damage to commercial and/or tourist shipping are not well constrained. As a result, there remains a real prospect of environmental emergencies arising from damage to, or sinking of commercial shipping, and/or humanitarian crises resulting from increasing tourist cruise ship traffic (where several hundred people on board may require evacuation and rescue).
Research on this topic is ongoing at the University of Liverpool (e.g. Shiggins et al., 2023[12]; and through the lead author’s UKRI Future Leaders Fellowship on ice sheet change). However, what controls the size distribution of icebergs calving from glaciers is still poorly understood. Gaining greater understanding of how these risks may evolve will potentially have significant implications for future safety of shipping and infrastructure in the Arctic, especially given the ongoing war in Ukraine increasing geopolitical uncertainty surrounding future use of the relatively iceberg free Northern Sea Route (across Russian waters). If such a geopolitical situation was to persist, as Arctic sea ice reduces, the Northwest Passage and Trans-Arctic sea routes are the most likely routes for European and eastern seaboard US shipping between the Atlantic and Pacific. However, both of these sea routes come with greater iceberg risk from the Greenland ice sheet and Canadian ice caps.
Loss of ice due to surface melting: Meltwater runoff from the Greenland Ice Sheet and other glaciers and ice caps of the High Arctic is important for sea level rise but also for marine biogeochemistry and overall ocean productivity. Additionally, the changing spatial distribution of meltwater runoff from around the Greenland Ice Sheet and the High Arctic ice caps is important for understanding downstream impacts on changes in ocean circulation and heat exchange with the atmosphere (i.e. North Atlantic weather). Combined with research into the ice sheet itself, the enhanced research capability offered by the RRS Sir David Attenbrough places the UK in an excellent position to address these key issues affecting ice, land, ocean and atmosphere interactions alongside international collaborators.
Estimates of ice loss arising from the imbalance between snowfall and surface melting (also known as surface mass balance (SMB)) are derived from the combination of satellite measurements and ice sheet surface mass balance models. From 2010-2018 this imbalance in Greenland has resulted in the loss of 160±20 gigatonnes of ice per year[13], equivalent to ~40% of recent annual ice loss from the Greenland ice sheet. For other Arctic ice caps and glaciers, their small size and highly variable topography make pan-Arctic assessments of ice loss from the glacier surface challenging. However, for Svalbard, runoff has been found to be increasing at a rate of 3.7 gigatonnes per year every decade[14], while several glaciated regions are known to have contributed significantly towards sea level rise between 1971 and 2017 (Alaska, 5.7 ± 2.2 mm; Arctic Canada, 3.2 ± 0.7 mm; and the Russian High Arctic, 1.5 ± 0.4 mm)[15].
Understanding the future contribution of surface melting to sea level rise depends on numerical models that simulate processes occurring at the glacier surface and within the snowpack. The physics of melting glacier ice are well understood, however, significant uncertainty and research effort surrounds how models: (i) characterise albedo (i.e. the proportion of incoming radiation that is reflected back from the surface) of melting snow and ice surfaces; and (ii) treat the potential for surface meltwater to percolate and refreeze within low-density near surface firn (i.e. snow that has survived more than one summer). The latter is a process that can act to prevent, or at least reduce, the delivery of surface meltwater to the global ocean. Climate change is exacerbating these process uncertainties.
The albedo uncertainty is most dominant across lower elevation more marginal areas of glaciers and ice sheets where ablation (i.e. mass loss) dominates over winter accumulation of snow. Here considerable work focuses on whether increased fossil fuel emissions and consequent atmospheric warming, have reduced albedo (i.e. darkened the surface) through changes in surface micro-biology (e.g. algae) and/or from deposition of pollution (microscopic carbon) on the ice sheet surface[16],[17]. These factors act to enhance melt as a darker ice surface generates more melt through absorption of more radiative energy, creating the potential for a positive feedback between melt and warming.
Uncertainty surrounding the refreezing of meltwater within firn is increasingly important across the higher elevation interior regions of the ice caps and ice sheets, as both higher magnitudes and greater spatial extents of surface melting have occurred as climate warms[18]. Multiple recent “exceptional” melt seasons have been found to change the density of near-surface firn by creating potentially impermeable ice layers that are currently not well simulated by models[19]. These near surface ice layers are important components of understanding ice loss, as they can reduce the refreezing and storage capacity of near surface firn, causing more runoff for the same amount of melt. “Extreme” warm melt seasons that promote the growth of near surface ice layers will be the new norm in the decades ahead, so new model parameterisations are required that can effectively characterise the effects of melting, percolation, refreezing and runoff on overall mass loss from the ice sheets.
A further impact of a warming Arctic climate will be to increase the likelihood of precipitation falling on glacier ice as rain rather than snow, which can both exacerbate glacier melt[20] and affect glacier flow velocities[21]. “Rain on snow” events have the effect of reducing the aforementioned refreezing capacity of the firn (promoting increased meltwater runoff to the ocean), darkening the ice surface (promoting higher melt rates than would otherwise have occurred through increased absorption of solar radiation), and melting of the ice itself (as rainwater will be >0oC)[22]. It is therefore highly likely that these processes will act to increase glacier and ice sheet surface melting, and delivery of water to the ocean through the 21st century.
Section 2: Environmental impacts and risks of ice loss to future economic activity in Greenland
It is the aim of the Greenlandic government to take advantage of opportunities provided to the country by climate change, which will also likely impact UK international trade and ability to achieve net zero. These opportunities include (but are not limited to): exploitation of critical mineral reserves; clean energy production through hydropower generated by ice sheet melt; increased tourism; and expanding international shipping infrastructure for the opening of Arctic shipping routes. For example, in a speech in August 2022, Greenlandic Prime Minister Múte Egede outlined Greenland’s ambitions stating: “[...] the opportunities in the Arctic are great. Critical minerals, new opportunities due to climate change – including navigation opportunities where it was not possible before and not least our geographical location.”[23]
This section will cover three main areas that will impact local and international economic activity in Greenland that has relevance for the UK, namely: critical minerals; hydropower and clean fuel production; and shipping/port infrastructure.
Critical minerals: Greenland is home to the second largest global deposit of critical minerals, located at Kvanefjeld, South Greenland. This deposit has significant potential for the supply of critical minerals, expanding the market beyond China/Chinese-linked sources that currently account for up to 90% of global production[24]. Affordable access to critical minerals will be crucial to both the UK and international transition to net zero carbon emissions. However, the prospective future Kvanefjeld mine (and other potential locations of critical mineral extraction in Greenland) will be affected by iceberg production from nearby marine terminating glaciers. The potential response of these glaciers to future climate change in terms of their stability, and potential to produce larger or smaller icebergs is currently unknown. These factors pose a possible risk to mining infrastructure development, maintenance, and export of ore and/or refined products.
Future iceberg risk to critical mineral infrastructure (in addition to other types of infrastructure in similar settings) is an issue worth highlighting here given the manner in which iceberg producing glaciers retreat. Rather than gradually retreating in proportion to atmospheric and ocean warming, these glaciers can catastrophically retreat by several kilometers in the space of a few years after decades or even centuries of stability[25]. Greenlandic infrastructure therefore is at risk of encountering rapidly evolving iceberg risks that can affect access to mining sites (and therefore cost).
It is worth reiterating at this point that there is no known current risk of this occurring at Kvanefjeld, though this lack of understanding of risk is primarily due to the glaciers in the region not having been studied in detail. However, behaviour of other glaciers around Greenland demonstrate that these risks exist purely by virtue of marine terminating glaciers existing in the region.
Hydropower: The production of clean energy through harnessing the power of ice sheet runoff places Greenland as a potential hub for the creation of hydrogen based fuel. Availability of hydropower facilities adjacent to rare earth and non-rare earth mines also offers potential for on-site refining of mineral ore, reducing both production and shipping costs. However, two environmental factors will impact the potential longevity and viability of such schemes, the impacts of which are currently either unknown or poorly constrained.
Firstly, the supply of water to hydropower installations that rely on lakes not connected to glaciers or the ice sheet in Greenland will be reliant on having their levels maintained by rainfall and snow melt. There is currently significant uncertainty regarding how this may change in Greenland over the coming century. Effects of this are already being observed, with the Buksefjord hydroelectric plant that supplies Greenland’s capital Nuuk with the majority of its energy experiencing declining lake levels, requiring drilling of a pipeline to a nearby lake to supply sufficient water to maintain production[26]. Future patterns of snow and rainfall will therefore control the long term viability of prospective hydropower installations, and/or potentially limit levels of energy production.
Secondly, for hydropower installations that rely on meltwater supply from the ice sheet, variation in meltwater supply at timescales from hours to years will likely pose engineering and material science challenges for infrastructure development. While meltwater runoff from the ice sheet peaks in summer and declines to minimal levels in winter, short term variations can arise from either: short-term (e.g. hours to days) extreme melt events (e.g. July 2012 and August 2019); or rapid delivery of water through the catastrophic drainage of meltwater lakes that form on top of the ice sheet and/or lakes at the ice sheet margin. These drainage events are capable of delivering substantial volumes of meltwater to the ice sheet margins on timescales of less than a day. Consequently, the potential risks arising from this need to be accounted for in the design and building of hydropower installations. Knowledge of these risks can only be gained through detailed local scale studies that (to the knowledge of the authors) are rarely undertaken.
In addition to this, meltwater from glaciers and the ice sheet will contain varying amounts of sediment within it, impacting the operation of hydropower installations. Those installations that seek to use glacier or ice sheet meltwater for hydropower will therefore need to overcome design and/or material science challenges related to the longevity of turbines that may be worn down by sediment within the water itself. The concentration of sediment in meltwater varies through the year on timescales from hours to seasons, and is controlled by a combination of processes occurring at the glacier/ice sheet surface and underneath the ice at its bed[27]. Few previous studies on this have been undertaken due to the extremely labour and time intensive nature of data collection that is required. Understanding of how sediment concentration varies through time from one glacier to another, and therefore implications for hydropower generation is therefore currently poorly understood.
Port infrastructure: Similar to mining and hydropower infrastructure, Greenland’s port infrastructure is likely to experience evolving iceberg risk as glaciers continue to retreat. A notable example where this is already occurring is at Greenland’s largest deepwater port (Nuuk) where expansion of the port facilities is planned. At this location, the Sikuki (“ice free”) Harbour complex has had to be closed or have limited operation for several days during 2022 because of icebergs, demonstrating the potential for iceberg risk to disrupt port activity. This disruption has arisen from the rapid acceleration of a nearby marine terminating glacier that has increased its ice discharge by 200% since 2010 after more than 200 years of stability. Nuuk is currently therefore experiencing a “no-analogue” scenario with respect to ice risk, in that it has likely never experienced similar ice conditions since the city was founded in 1727. This glacier is also known to be at particular risk of further retreat and acceleration due to the topography of its underlying bedrock.
At the University of Liverpool we are currently monitoring this glacier in detail in collaboration with Asiaq Greenland Survey (the Greenland Government’s geoscience consultancy) as part of the Liverpool-Asiaq Glacier Observatory (LAGO). Work is currently ongoing to assess when and how long any potential disruption may last at Greenland’s key port that will likely become a future hub of international shipping through the Arctic.
Section 3: Collaboration and Cooperation in Arctic Science
Collaboration and cooperation with local communities, industry and international academic institutions underpin the success of UK research in the Arctic. The UK publishes the fourth highest number of academic articles about the Arctic, with a substantial proportion involving collaboration with non-UK partners (e.g. only 8 out of 94 papers published since 2010 by the authors of this submission had entirely UK-based authorship). In short, the success of UK scientific activity in the Arctic would not be possible without international collaboration.
The uncertainty relating to affiliation to the EU’s Horizon and Copernicus research programmes has already damaged collaborations with international colleagues. In our direct experience, EU researchers have expressed reticence about being part of UK bids/being included as partners despite UKRI’s offer to underpin funding. Even if the UK does eventually affiliate with the Horizon programme, it will take time to restore and reinvigorate these collaborations, as colleagues in Europe have sought to fill the gap left by the UK with new partners. With the agreement of the new Northern Ireland Protocol and increasing likelihood of Horizon affiliation, the creation of UK based schemes that support the reinvigoration of old collaborations and initiation of new ones with Horizon partners should be investigated. We also strongly encourage affiliation with the Copernicus programme that is currently in doubt.
Bi-lateral agreements that allow equitable collaboration on research projects such as those between NERC and NSF, NERC and NRCC (Canada), and newly between UKRI and Norwegian and Swedish research councils are extremely welcome in efforts to maintain and build international collaborations (though we note that the Sweden MoU does not currently include NERC remit science). Similarly, BEIS backed Science and Innovation bursaries with Canadian and Greenlandic research councils provide avenues to establish and build new partnerships between UK and Arctic researchers and communities. However, within a Greenlandic and Danish context, the prospect of UK academics collaborating on large projects is currently limited by research council rules preventing us costing in time commitment for colleagues from these countries.
Where possible, we would strongly encourage development of mutually beneficial relationships (similar to the UK-Norway MoU) with Danish, Greenlandic and other Arctic state partners where such agreements do not currently exist. While Science and Innovation Network bursaries with Greenland are a very welcome contribution, the potential longevity of the collaborations that these generate is placed at risk by the lack of an equitable ongoing funding agreement that would support larger scale, cutting edge science in the longer term. This is especially the case with respect to Greenland, where current funding structures can make genuinely mutually beneficial collaboration with local communities and organisations challenging. If the status quo were to persist, this would undermine the UK’s stated ambition towards “empower[ing] and ensur[ing] the full involvement of Indigenous researchers as respected partners in Arctic research”[28].
Authors
Lead author:
Dr James Lea, Reader in Glaciology, UKRI Future Leaders Fellow
Co-authors:
Dr Stephen Brough, Lecturer in Glaciology
Prof Douglas Mair, Professor in Glaciology, Head of School of Environmental Sciences
Dr Isabel Nias, Lecturer in Glaciology
Mr Connor Shiggins, Postdoctoral Researcher in Glaciology
April 2023