Direct, geodetic and simulated mass balance of the Kolahoi Glacier in the Upper Indus basin
Shakil Romshoo, Tariq Abdullah
Corresponding author: Shakil Romshoo
Corresponding author e-mail: shakilrom@uok.edu.in
The glaciological mass balance of the Kolahoi Glacier in the upper Indus basin from 2014–19, the geodetic mass balance from 2000–14, and the reconstructed mass balance since 1980 are all presented in this study. The average observed mass balance of the glacier was –0.84 ± 0.34 m w.e. a–1 for the five years observation period, with significant inter-annual variation. The observed mass balance matches the geodetic mass balance estimate of 0.90 ± 0.09 m w.e a–1quite well. Using daily air temperature and precipitation measurements from the nearest observatory, the mass balance was reconstructed using the temperature-index and accumulation models. Field measurements at ablation stakes in various altitudinal ranges were used to calculate degree day factors for snow and ice but the precipitation gradient was adjusted during the model calibration. Despite the fact that the glacier has been losing mass since 1980, the reconstructed mass balance reveals four distinct glacier recession episodes. Period I (1980–90) had lower mass loss rates (–0.27 ± 0.42 m w.e. a–1), with four positive mass balance years. Significant mass loss was seen in periods II (2000–10) and IV (2010–19) with rates of –1.01 ± 0.42 m w.e. a–1 and –1.13 ± 0.42 m w.e. a–1 respectively. Over the entire simulation period, period III (2000–10) saw the greatest mass loss (–1.18 m w.e. a–1).The modelled glacier-wide mass balance is sensitive to temperature at –0.65 m w.e. a–1 °C–1, whereas the sensitivity to precipitation is simulated at 0.13 m w.e. a–1 for a 10% change
Mathias Albert
Corresponding author: Mathias Albert
Corresponding author e-mail: mathias.albert@uni-bielefeld.de
This is a presentation of the research project ‘The Worldviews of Ice. Constructions of the Arctic at the Science/Politics Interface’, funded by the German Research Foundation and running from March 2022 to February 2025. The project studies how competing narratives of the Arctic, and particularly also its representations as an ice-covered region, are imbued with geopolitical images, are produced in, and altered through, closely connected epistemic communities that link the sciences to politics. Its aim is (1) to trace how these images are co-produced at relevant interfaces between scientific and political communities dealing with Arctic issues, (2) to inquire how these images are transmitted into, and received within, wider Arctic epistemic communities, and (3) to show in an exemplary fashion how such images can influence, and actually have influenced, policy-making. The project starts from the observation that science and politics do not relate to each other in simple or punctual communicative interaction settings, but are tied together in competing narratives that influence, and in turn are influenced by, images of how the world (in this case: the Arctic) looks like. The project studies the evolution of these narratives and underlying images through epistemic communities and science/politics networks. It looks at different boundary constellations at the science/policy nexus in three closely related case studies, selected in order to represent an ideal-typical, sequential understanding of the process of knowledge generation (i.e. funding, ‘doing’ research, ‘selling’ results). The purpose of the presentation of this social science project in the context of a glaciological symposium is both to contribute to interdisciplinary dialogue, as well as to establish contacts with glaciologists who themselves could become valuable partners for conducting expert interviews in the project.
Disentangling anthropogenic from natural drivers of the climate variability in High Mountain Asia
María Santolaria-Otín, Martin Ménégoz, Laurent Terray, Mickaël Lalande, Javier García-Serrano
Corresponding author: María Santolaria-Otín
Corresponding author e-mail: maria.santolaria@bc3research.org
Climate change in High Mountain Asia (HMA) is largely uncertain because the lack of local observations does not allow a proper estimation of long-term trends. The complex topography induces marked heterogeneities of the atmospheric variables in an area under the influence of both the Asian monsoons and the Western disturbances, two circulation patterns that show considerable variability from daily to decadal timescales. It is therefore challenging to simulate the climate variability in HMA. The ongoing retreat of glaciers observed in the Southern Himalayas suggests a significant warming signal, since there is no clear trend of precipitation in this area. The relative stability of the glaciers located on the western part of HMA observed over the last decades, with some glaciers showing even positive mass balance in the Karakoram region is more difficult to interpret. To explain this ‘Karakoram anomaly’, several physical processes have been suggested, including cloud changes, summer cooling and winter snowfall increase. However, there is no consensus on the exact causes of this phenomenon and their relative contributions, including the role of anthropogenic influence. A general increase in precipitation is expected in this area, in relation to the warming associated with greenhouse gases that favour higher moisture rates in the atmosphere. This effect contrasts with the increase in aerosol concentrations observed in the Indian subcontinent that induces a local cooling and a weakening of the monsoon systems. In this study, a large set of observational and model datasets is used to investigate dynamical versus thermodynamic atmospheric changes in this area. Trends are decomposed to disentangle atmospheric circulation changes from thermodynamic signals, with their respective imprints in temperature, precipitation and snow cover. The method is first applied to observations to directly interpret the atmospheric trends over the last decades as well as their potential impacts on the cryosphere. Then, climate simulations including and excluding anthropogenic forcings, as well as single forcing experiments considering separately aerosols and greenhouse gases (DAMIP) are used to highlight their signature in the climate of HMA.
Reduced mass loss from the Greenland ice sheet under stratospheric aerosol injection
John C. Moore, Ralf Greve, Thomas Zwinger, Fabien Gillet-Chaulet, Chao Yue, Liyun Zhao, Heiko Goelzer
Corresponding author: John C. Moore
Corresponding author e-mail: greve@lowtem.hokudai.ac.jp
Stratospheric aerosol injection (SAI) has been proposed as a potential method of mitigating some of the adverse effects of anthropogenic climate change, including sea-level rise from the ice sheets. In this study, we use the SICOPOLIS (www.sicopolis.net) and Elmer/Ice (elmerice.elmerfem.org) dynamic models driven by changes in surface mass balance, surface temperature and ocean temperature (similar to ISMIP6-Greenland) to estimate the sea-level-rise contribution from the Greenland ice sheet under the IPCC RCP4.5, RCP8.5 and GeoMIP G4 scenarios. The G4 scenario adds 5 Tg a–1 sulfate aerosols to the equatorial lower stratosphere to the IPCC RCP4.5 scenario. We simulate the mass loss of the Greenland ice sheet for the period 2015–2090 under the three scenarios with four earth system models, using SICOPOLIS with hybrid shallow-ice-shelfy stream dynamics and Elmer/Ice in the Elmer/Ice-sheet set-up with shelfy stream dynamics. For atmosphere-only forcing, the results from the two ice-sheet models are very similar. Relative to the constant-climate control simulations (CTRL), the losses from 2015–90 are 64 [53, 80] mm SLE for RCP8.5, 46 [38, 53] mm SLE for RCP4.5 and 28 [18, 39] mm SLE for G4 (mean and full range). Thus, the mean mass loss under G4 is about 38% smaller than that under RCP4.5. For both models, the accumulated SMB is larger than the actual ice loss because, as the ice sheet recedes further from the coast, the mass loss due to calving is reduced. We will also investigate the response of the ice sheet to ocean-only forcing and combined atmospheric and oceanic forcing.
Jennifer Huidobro, Julene Aramendia, Leire Coloma, Iratxe Población, Cristina Garcia Florentino, Kepa Castro, Gorka Arana, Juan Manuel Madariaga
Corresponding author: Jennifer Huidobro
Corresponding author e-mail: jennihuidobro@gmail.com
Hydrated minerals trace the past and present history of water on Earth and other planets. In fact, orbiters, rovers and landers found hydrated minerals on Mars, such as gypsum (CaSO4.2H2O), bassanite (CaSO4.½H2O) and anhydrite (CaSO4). In addition, other mixtures of hydrated sulfates, such as syngenite [K2Ca(SO4)2·H2O] and görgeyite [K2Ca5(SO4)6·H2O], are expected on Mars. Understanding the presence of these minerals and their relationship with Martian environment will provide a better knowledge of the Martian water history. Raman spectroscopy is the most novel technique used on Martian surface to study the mineralogy. Indeed, the NASA’s Mars2020 rover and the ESA’s ExoMars rover are equipped with Raman spectrometers. Considering this, this work studies the influence of low Martian temperatures on Raman spectra of gypsum, syngenite and görgeyite, minerals that were previously synthesized. A Renishaw inVia micro-Raman spectrometer equipped with a 532 nm of excitation laser and a high sensitive CCD detector was used. The spectrometer was coupled with a temperature-controlled stage THMS600/HFS600 Linkam Scientific Instrument for the temperature control. Raman spectra were obtained every –10°C from 0 to –100°C. When the desired temperature was reached, a 6-minute hold was programmed to perform 4 Raman measurements from 100 to 4000 cm–1 for checking reproducibility. In the case of gypsum, its main Raman band (~1008 cm–1) was shifted to higher wavenumbers when temperature decreased. The first water band also shifted linearly towards higher wavenumbers with decreasing temperature. In contrast, the second water band shifted towards lower wavenumbers with the temperature decreased. One of the main Raman bands of syngenite (~982 cm–1) did not shift under temperature changes. However, the other main band (~1006 cm–1) shifted to higher wavenumbers when temperature decreased. Besides, the two water bands shifted linearly to lower wavenumbers when temperature decreased. Finally, any change with temperature were observed in the Raman bands during the görgeyite experiments. In conclusion, this work shows that some Raman bands for syngenite and gypsum could act as thermometers, serving as supporting science for missions that include a Raman instrument in their payload.
Weathering alteration in Antarctica environment as seen in the MIL090030 Martian nakhlite
Leire Coloma, Julene Aramendia, Jennifer Huidobro, Iratxe Población, Cristina Garcia Florentino, Kepa Castro, Gorka Arana, Juan Manuel Madariaga
Corresponding author: Leire Coloma
Corresponding author e-mail: jennihuidobro@gmail.com
Meteorites are the only form that we have on Earth to study space. These meteorites suffer different types of alteration, one of them being the weathering alteration caused by environmental conditions at the site where the meteorite lands on Earth. One site where meteorites are easily found is Antarctica. By the geochemical study of meteorites, the alteration that takes place there can be ascertained. In this way, the Martian meteorite Miller Range 090030 (MIL090030) was analyzed using Raman spectroscopy and X-ray fluorescence (ED-XRF). One of the alteration compounds found by Raman sSpectroscopy is the presence of gypsum (CaSO4·2H2O) and anhydrite (CaSO4) at the same time. Both minerals have been found on the surface of Mars so they could be original from this planet. However, gypsum was probably dehydrated to anhydrite during the formation of the meteorite or the impact on arrival on Earth due to the high temperatures and pressures reached in these processes. Therefore, it could be said that all the calcium sulphate arrived as anhydrite on Earth. Thus, the presence of gypsum on the meteorite is linked to the weathering conditions in Antarctica where anhydrite would be hydrated to form gypsum again. Due to the short time that meteorite was on the Earth, not all anhydrite has been hydrated, so both minerals were found at once. Moreover, we found NaCl by ED-XRF. The Antarctic environment is rich in this compound due to the nearby sea, so NaCl is precipitated on the meteorite because of the evaporation of water. Two types of nitrate, nitratine (NaNO3) and niter (KNO3) were also found by Raman spectroscopy and Raman image. These nitrates are, unfortunately, currently common compounds in Antarctica due to aerosol transport from the South-American continent and can be deposited on the meteorite. These alteration compounds have not been detected in other Earth fields of meteorites, such as deserts, so their presence is due to the particular environment of Antarctica. ACKNOWLEDGMENTS: All authors are grateful to NASA for accessing to the MIL090030 Martian meteorite through the loan agreement between NASA’s JSC and the IBeA Research Group of the UPV/EHU.
Relative sea level predictions for coastal stakeholders
Michael Wolovick, Angelika Humbert, Veit Helm, Thomas Kleiner, Martin Rueckamp, Ralph Timmermann
Corresponding author: Michael Wolovick
Corresponding author e-mail: wolovick@princeton.edu
Sea level rise from melting ice sheets in a warming climate will pose a substantial threat to coastal communities in the coming centuries. However, the geographic distribution of sea level rise is strongly affected by the pattern of ice sheet mass loss, as the changes in ice sheet mass induce perturbations to the Earth’s gravitational and rotational potentials, along with deformation of the solid Earth. These local changes in sea level are of utmost importance to coastal stakeholders, yet there remains a gap between the scientific knowledge that exists and the planning tools available to stakeholders. Here, we use the global sea level model within the Ice Sheet and Sea Level System Model, ISSM-SESAW, to predict global changes in relative sea level accounting for gravitational, elastic, and rotational effects. We force the model both with historical Greenland and Antarctic ice sheet mass changes observed with satellite altimetry, and with ISMIP6 model projections of future change. We evaluate the sea level rise for a wide distribution of coastal sites in both the Global North and the Global South. These modeling efforts represent the first step in building a web tool for efficiently disseminating knowledge of local sea level changes, and of vulnerabilities to specific ice sheet sectors, to the stakeholders who must make decisions based on that knowledge.
Feasibility of ice sheet conservation using seabed anchored curtains
Michael Wolovick, John Moore, Bowie Keefer
Corresponding author: Michael Wolovick
Corresponding author e-mail: wolovick@princeton.edu
Sea level rise over the next few centuries is expected to be rapid and extremely damaging to coastal communities and infrastructure, with unavoidable losses and coastal protection costs in the tens of billions per year. Retreat of Thwaites and Pine Island glaciers is likely already in an unstable regime as their floating shelves are ablated by deep intruding layers of relatively warm seawater and their grounding lines are retreating down retrograde slopes. We suggest that warm water can be blocked from reaching the grounding line by thin flexible buoyant curtains anchored to the seabed. The consequent reduction in ice shelf melting could result in increased ice sheet buttressing as the shelf makes contact with natural seabed highs. Thin flexible curtains are less costly than the solid artificial barriers that have been proposed previously, more robust against iceberg collisions, easier to repair in the event of damage, and easier to remove in the event of unforeseen side effects. We illustrate the technical viability of this approach by evaluating simple curtain design concepts, feasible methods of installation, and potential curtain routes in the Amundsen Sea. We find that suitable materials are commonly available, and that installation of a seabed curtain in temperate ocean waters would be within the capabilities of existing offshore and deep ocean construction techniques. Installation in polar waters presents severe additional challenges from icebergs, harsh weather, and brief working seasons, which can, however, be overcome with present-day technology. Furthermore, the primary inflow route of warm water towards the grounding line of Thwaites Glacier could be blocked with a curtain only 4 km long. We also attempt a back of the envelope cost estimate for a longer curtain route, and find that an 80 km long curtain that protected both Pine Island and Thwaites glaciers, installed in 600 m deep waters on alluvial sediments, would cost roughly $40-80 billion up front, with $1–2 billion a–1 ongoing maintenance costs after that. These costs compare favorably with the costs of global coastline protection (∼$50 billion a–1) that would be needed in the event of West Antarctic collapse.
Numerical approximation of viscous contact problems applied to glacial sliding
Gonzalo Gonzalez de Diego, Ian Hewitt, Patrick Farrell
Corresponding author: Gonzalo Gonzalez de Diego
Corresponding author e-mail: gonzalezdedi@maths.ox.ac.uk
Viscous contact problems describe the time evolution of fluid flows in contact with a surface from which they can detach and reattach. These problems are of particular importance in glaciology, where they arise in the study of grounding lines and subglacial cavities. In this presentation, we explain how robust numerical algorithms can be built for these problems by reformulating them as variational inequalities with a Lagrange multiplier. We then present numerical results for an ice sheet sliding over a sinusoidal bed under both steady and unsteady conditions. We first reconstruct a steady sliding curve by finding steady cavity shapes for different water pressures. Then, we perturb these steady states by oscillating the value of the water pressure in time. Our numerical exploration of unsteady sliding is motivated by field measurements in alpine glaciers and in the Greenland ice sheet that find strong variations in subglacial water pressures in time scales down to hours. Our results in this idealized setting indicate that the effect of unsteady water pressures depends strongly on the location of the initial steady state along the sliding curve. In particular, we find that if the steady state is located on the downsloping or rate-weakening part of the friction law, the cavity evolves towards the upsloping section, indicating that the downsloping part is unstable.
Martyn Tranter, Alex Anesio, Liane Benning
Corresponding author: Martyn Tranter
Corresponding author e-mail: martyn.tranter@envs.au.dk
A thin, elongated stripe of dark surface ice develops along the western margin of the Greenland ice sheet each year, a region that produces significant quantities of runoff from the ice sheet during the melt season. The factors influencing the annual growth increase of this Dark Zone have been contested, and include the enhanced deposition of black carbon and/or atmospheric dust, melt out from more dusty ice layers and an increase in the water content of the surface ice. However, it is now becoming established that pigmented glacier ice algae are a dominant control on the darkening of the surface ice, accounting for a minimum of 13%, and locally a maximum of 26%, extra melt production each year as a result of the heating caused by their adsorption of solar radiation. The ice algae community is dominated by two species, Ancylonema nordenskiöldii and A. alaskanum, both which contain a deep purple pigment, purpurogallin, which led us to name our ERC Synergy Project DEEP PURPLE. These algae have been observed on glaciers worldwide. The purple pigment protects the vital apparatus in the algal cells from high levels of solar radiation incident on the ice sheet surface. There are often so many of these deep purple cells that the ice surface looks black. Field observations confirm that ice algae bloom and darken the surface, but what is not known at present is what limits the biological darkening of surface ice in present day melt zones, and whether the expanded melt zones of our warming world will, too, be biologically darkened. DEEP PURPLE is addressing these issues. We contend that the likely limits to growth include factors such as the length of the melt season, the genetic make-up of the algae, the annual life cycle of the algae, including the entombment, survival and re-emergence of active algae post winter, grazing and viral controls on growth, the nutrient content of the melting surface ice environment, a porous, permeable layer of rotting ice known as the weathering crust, the types of habitats that the weathering crust provides, the longevity of particular niches within which the algae thrive, physical wash away of the algae from the weathering crust by periods of heavy rain or high melting. Satellite remote sensing is being used to upscale our results and to confirm processes over the ice sheet. We are engaging the modelling community to include bioalbedo in predictive melt modelling.
Lauren Gregoire, Niall Gandy, Lachlan Astfalck, Ruza Ivanovic, Sam Sherriff-Tadano, Robin Smith, Daniel Williamson
Corresponding author: Lauren Gregoire
Corresponding author e-mail: l.j.gregoire@leeds.ac.uk
Coupled climate-ice sheet models are crucial to evaluating climate-ice feedbacks’ role in future ice sheet evolution. Such models are calibrated on the present day, but current observations alone are insufficient to constrain the strength of climate-ice feedbacks. The extent of the Northern Hemisphere ice sheets during the last glacial maximum, ~20 000 years ago, is well known and could provide a benchmark for calibrating coupled climate-ice sheet models. To test this, we apply Bayesian uncertainty quantification methods to the FAMOUS-ice coupled climate–ice sheet model, a fast GCM coupled to the Glimmer ice sheet model. We ran Last Glacial Maximum simulations using FAMOUS-ice with interactive North American ice sheet. We find that the standard model setup, calibrated to produce a suitable present-day Greenland, produced a collapsed North American ice sheet at the Last Glacial Maximum. We ran ensembles of hundreds of simulations to explore the influence of uncertain ice sheet, albedo, atmospheric, and oceanic parameters on the ice sheet extent. The North American continent deglaciated rapidly in most of our simulations, leaving only a handful of useful simulations out of 280. We thus developed a method to efficiently identify regions of the parameter space that can produce a reasonable ice-sheet extent. This involved emulating the equilibrium ice volume and area as a function of the surface mass balance at the start of our simulations. We then ran three waves of short simulations for 20–50 years to identify parameter values and surface mass balance conditions potentially suitable to grow a realistic ice sheet. This enabled us to find ~160 simulations with good ice extent. Through analysis of these simulations, we find that albedo parameters determine the majority of uncertainty when simulating the Last Glacial Maximum North American ice sheets. The differences in cloud cover over the ablation zones of the North American and Greenland ice sheet explains why the ice sheets have different sensitivities to surface mass balance parameters. Based on our work, we propose that the Last Glacial Maximum can provide an ‘out-of-sample’ target to avoid over calibrating coupled climate-ice sheet models to the present day.
Anderson Ribeiro de Figueiredo, Jefferson Cardia Simões, Rualdo Menegat, Sarah Strauss
Corresponding author: Anderson Ribeiro de Figueiredo
Corresponding author e-mail: anderson.figueiredo@ufrgs.br
The populations that inhabit the periglacial regions of the Central Andes have invariably been susceptible to glacier-related hazards. Therefore, it is crucial to understand that climate change impacts glaciers and how climate risks like glacial lake outburst floods (GLOFs) in the Peruvian Andes have been managed. This work addresses the need for a historical and geographical reinterpretation from a decolonial perspective. We analyze the human occupation in the Cordillera Blanca region to understand the adaptation culture to periglacial mountain environments through time. This research was performed for two historical periods: an older period where pre-Columbian civilizations’ occupation strategies were identified and another more recent period where postcolonial strategies were considered against the risk of glacier-related disasters. The results show that ancestral Andean societies selected settlement sites to minimize the risk of glacier-related disasters: predominantly occupied high mountainous slopes, and few archaeological sites were found in high-risk areas of glacier-related disasters. Therefore, it is pertinent to recognize native cultures as societies adapted to glacier-related disasters. The Andean socio-cryosphere denotes a long and continuous human occupation over a glacial and periglacial region on the mountains where a distinctive culture and cognition were developed. The knowledge developed by an Andean ancestral community and specific to a place can be defined as ethno-geoknowledge. However, the most populated postcolonial cities are located in high-risk zones of GLOFs, such as Huaraz. The recognition of the geographical position of these cities predominantly in high-risk areas as a mark of Spanish colonialism is essential. The reducciones, for example, was a system of resettlement to control indigenous people, which had several implications. We suggest that colonialism implied a disruption of the Andean cognitive system. It is critical to highlight that we do not claim that there were no pre-Columbian settlements in high-risk areas, but only that there were fewer compared with postcolonial civilizations. In short, this work shows that colonial settlers selected sites based on criteria that differed from those of indigenous communities, which may have reflected differing perceptions of risk.
Nicolas Gonzalez Santacruz, Sérgio Henrique Faria, Ana Moreno, Miguel Bartolomé, Patricia Muñoz Marzagon
Corresponding author: Nicolas Gonzalez Santacruz
Corresponding author e-mail: n.gonzalez@bc3research.org
The ice of mountain glaciers records the climatic features of the environment at the time of its formation, being especially sensitive to shifts in temperature and precipitation. The reaction time to environmental changes of glaciers is directly proportional to their size. For this reason, small glaciers (<0.5 km2) are key to understanding recent climate variability. Glaciers located in the central Pyrenees belong to this type and are also some of the southernmost glaciers in Europe. One of the most intensively studied glaciers in this area is the Monte Perdido glacier, and its ice keeps essential information to understand the climatic evolution and the effects of climate change over the Pyrenees during the last 2000 years. According to recent forecasts, this ice with that significant scientific value will disappear over the next few decades. Almost all the microstructural studies have traditionally been carried out on polar ice sheets, where ice cores can have several thousand meters. However, there is no thorough survey about ice microstructure in temperate glaciers, even though microscale processes are essential to understanding the mechanical behavior of ice masses and the preservation of climate records. This study aims to carry out the first comprehensive characterization of the ice microstructure of a mountain glacier (Monte Perdido), analyzing three vertical ice cores and several horizontal cores extracted in 2017 by the Pyrenean Institute of Ecology. We will compare the results with other microstructural studies performed on polar ice, where this science is much more developed. To accomplish a correct comparison, we will use ice cores drilled from cold areas (Antarctica; EDLM, EDC, DomeF), passing through slightly warmer climates like Greenland (GRIP; GISP2, NGRIP), and finally from glacier ice of temperate climates (Alps; Colle Gnifetti Glacier, Mont Blanc, or Rhone). Following this strategy, we will try to monitor how the microstructure evolves as a function of climate and gradually approach the characteristics that a glacier would have in a climatic context such as that of the Monte Perdido. After the characterization, we will look for the parallels and discrepancies concerning the other cores and the climatic and mechanical significance.
Nerea Bilbao-Barrenetxea, Yuwei Wu, María Santolaria-Otín, Stefano Balbi, Sérgio Henrique Faria
Corresponding author: Nerea Bilbao-Barrenetxea
Corresponding author e-mail: nerea.bilbao@bc3research.org
The Pyrenees, located between the Atlantic and Mediterranean climates, are an example of high mountains undergoing rapid changes in environmental conditions. These changes have impacts on the water cycle and water availability downstream, as well as on snow- related variables. Projections of climate change in hydro-climatic variables that consider different models and emission scenarios are necessary for stakeholders to make well-informed decisions to adapt to the new hydro-climatic conditions. In this context, we present a methodology that aims to analyze the mountain region as a whole by developing a hydrological model in ARIES that will be fed by climate data from different observational sources and climate models of the EURO-CORDEX, MED-CORDEX, and CMIP5 projects. We will pay special attention to the considered climate data, whether observational or model-derived, whose performance will be analyzed in depth. The developed hydrological model is a flexible time-spatial-scale hydrologic process model, inspired by the InVEST Seasonal Water Yield Model methodology of the Natural Capital Project. In order to understand the hydrological processes in the Pyrenees region, the model calculates the relative contribution of the plots to the generation of surface runoff and baseflow. The model focuses on the net amount of water produced on a pixel, and it takes into account the water subsidy from upslope pixels to a pixel and the actual streamflow generated by that pixel. The computation of surface runoff and evapotranspiration are based on a revised SCS Curve Number method and the modified Hargreaves equation respectively, while the infiltration and baseflow are computed according to the D8 flow direction and water balance, at watershed level. All data and model results will be integrated and aggregated into the ARIES platform. This methodology, designed for the Pyrenees region, will later be applied to other high-mountain regions with different data availability.
Presence of Eemian ice in the Renland ice cap, East Greenland, supported by radar and ice core data
Iben Koldtoft, Christian Panton, John Paden, Bo Vinther, Christine Hvidberg
Corresponding author: Iben Koldtoft
Corresponding author e-mail: ch@gfy.ku.dk
The Renland ice cap, East Greenland, is located at a high-elevation plateau in the eastern mountains of Greenland, with an elevation of 2340 m, an ice thickness of almost 600 m, and a few steep outlet glaciers flowing in valleys that reach all the way to sea level in the surrounding fjords. The Renland ice cap is believed to be strongly constrained by the topography. It is thus an ideal site to search for old ice and to obtain an ice core record with a pure climate signal undisturbed by elevation changes. In 2015, the Renland ice cap project (RECAP) drilled an ice core to the bottom of the Renland ice cap. Here, we present the results of a ground-penetrating radar (GPR) survey to select the location of an ice core drilling campaign, which occurred in 2015 prior to the ice core drilling, combined with the ice core timescale to search for ice from the previous interglacial, the Eemian, 130 000–115 000 years before present. The radar survey used a GPR radar developed for use on the Renland ice cap. This instrument is able to detect individual reflectors near the bedrock, which airborne surveys are largely unable to resolve. The radar stratigraphy is combined with the ice core timescale to trace the transitions of glacial/interglacial ice. An ice flow model tuned to the ice core timescale, suggest that the bottom ice may rest in a bedrock depression with limited flow. Our results show that a layer of Eemian ice is present at the bottom of the Renland ice cap and can be traced over several km, and suggest that the Renland ice cap has been very stable through the last glacial cycle with limited response to climate changes.
Francisco Navarro, Marc Oliva, Cayetana C. Recio-Blitz, Kaian Shahateet, María Isabel de Corcuera, Jaime Otero, Ricardo Rodríguez-Cielos, Andrés Díez-Galilea
Corresponding author: Francisco Navarro
Corresponding author e-mail: francisco.navarro@upm.es
The Antarctic Peninsula (AP) region, including the South Shetland Islands (SSI), showed during the second half of the 20th century one of the strongest warming trends on Earth, followed by a regional cooling period, particularly intense in the northern AP. The stacked regional temperature record shifted from a warming trend of 0.32°C/decade over 1979–97 to a cooling trend of –0.47°C/decade over 1999–2014. Since the mid 2010s, the region has returned to a warming trend. In the N and NE AP and the SSI, the cooling period involved a decrease in summer mean temperature by 0.5°C from 1996–2005 to 2006–15. Though not an extreme change, it implied regional changes in, for example, the glacier mass balance, the thickness of the active layer of permafrost, the snow cover extent and duration, and the life cycle of lichens. We here focus on the changes in glacier mass balance during the cooling period. SSI glaciers such as Hurd and Johnson’s, in Livingston Island, are extremely sensitive to temperature changes. Melting modelling on Johnson’s Glacier has shown that a 0.5°C temperature increase (decrease) implies a 56% (44%) increase (decrease) in melt rate. The reason is that the average summer surface temperature is very close to 0°C over large portions of these glaciers, so small summer temperature changes can imply a switch from non-melting to melting conditions or vice versa. We analyse the geodetic mass balance (GMB) of Hurd (land-terminating) and Johnson’s (tidewater) glaciers over the periods 1957–2000 and 2000–13, as well as the climatic mass balance (CMB), by the glaciological method, during the period 2002–16, which, combined with a calving estimate for Johnson’s Glacier allow an estimate of the total mass balance by two independent methods, although the periods do not exactly match. The total mass balance 2002-2016 combining CMB and calving (for Johnson’s) were –0.04 ± 0.11 (Hurd) and 0.07 ± 0.09 (Johnson’s) m w.e. a–1, virtually in balance, while corresponding GMB values were –0.21 ± 0.08 and –0.14 ± 0.10 m w.e. a–1. The difference is likely due to the fact that the GMB estimate excludes the three coldest years, with the most positive CMBs (2014–16). GMB analysis involving most of the SSI for the period 2013–17 supports this, as the result for Livingston Island was positive, at 0.13 ± 0.01 m w.e. a–1, while the average for the SSI was slightly negative, at –0.11 ± 0.01 m w.e. a–1. This project was funded by grant PID2020-113051RB-C31 from MCIN/AEI.
Ice–ocean interactions in Antarctica and its contribution to sea level in the coming centuries
Antonio Juárez-Martínez, Javier Blasco, Marisa Montoya, Jorge Álvarez-Solas, Alexander Robinson
Corresponding author: Antonio Juárez-Martínez
Corresponding author e-mail: antjua01@ucm.es
Sea-level rise in response to climate change represents one of the biggest threats that society will have to face in the coming centuries. In the mid-long term, the Antarctic Ice Sheet (AIS) could become the main contributor to sea-level rise, especially through a reduction of its western sector, the West Antarctic Ice Sheet (WAIS). The WAIS is marine-based and therefore strongly exposed to interactions with the ocean. Nonetheless, there is substantial uncertainty in the future contribution of the AIS to sea-level rise, mainly as a result of a poor understanding of physical processes such as ice-sheet dynamics and ice-ocean interactions. The structural uncertainty in future AIS projections has been studied as part of the Ice Sheet Model Intercomparison Project (ISMIP6). The first results showed that the sea-level contribution of the AIS increases with increasing emission scenarios, as expected. Nevertheless, the WAIS response to the warming varies widely among the models, with the climate forcing and the ocean-induced melt rates and calibrations being the largest sources of uncertainty. We herein investigate the contribution of the higher-order ice-sheet model Yelmo to the ISMIP6 projections. Our results show a strong sensitivity of the AIS contribution to sea-level rise to the calibration of the basal-melting parametrization, particularly remarkable in the WAIS, but in the range of the results reached by other ice-sheet models in the context of the ISMIP6 intercomparison project.
Assessment of the sensitivity of ice-sheet model Yelmo to ice-shelf collapse
Sergio Pérez-Montero, Javier Blasco, Alexander Robinson, Marisa Montoya, Jorge Alvarez-Solas
Corresponding author: Sergio Pérez-Montero
Corresponding author e-mail: sepere07@ucm.es
Sea-level rise projections under climate change show large uncertainty, mainly due to the potential contribution of the ice sheets. A major source of uncertainty is the Antarctic Ice-Sheet (AIS) due to the marine-based nature of its western sector, the West Antarctic Ice-Sheet (WAIS). Most of the WAIS is grounded under sea level and thus in contact with the surrounding ocean via floating ice shelves. Melting of ice shelves does not directly contribute to sea level rise but it modulates the ice flow towards the sea by controlling the discharge through the grounding line. However, the processes that regulate the ice flow and the discharge across the grounding line are neither fully understood nor well represented in state-of-the-art models due to the complexity of the various feedbacks involved. Two such processes are the basal friction or sliding law that governs the ice dynamics and melting close to the grounding line. Different models use different representations of both processes. In this context, the recent Antarctic BUttressing Intercomparison Project (ABUMIP) aimed to assess the structural (model-related) uncertainty in the response of the AIS to a sudden and maintained collapse of its ice shelves. Here we revisit the experiments of ABUMIP with the thermomechanical ice-sheet model Yelmo and extend them by additionally assessing the effect of using different friction laws and basal melting in the grounding line.
Tanguy Sandré, Jeanne Gherardi, Jean-Michel Huctin, Jean-Paul Vanderlinden
Corresponding author: Tanguy Sandré
Corresponding author e-mail: tanguy.sandre@uvsq.fr
While diverse Arctic realities tend to be integrated into the science-based narrative of climate and environmental change, locally based narratives elicit grounded experiences of resilience in the face of a changing climate. For instance, climate-change-driven variations in the sea-ice thickness and extent are ubiquitous in the narratives we have been collected in Ittoqqortoormiit (East Greenland) and Uummannaq (West Greenland). ‘When will the ice wrap itself again around the 350-inhabitant village?’ Our question has been left unanswered in the course of 2 months’ fieldwork in Ittoqqortoormiit; meanwhile, convergent stories were told: ‘in the past, the fjord would have been covered by thick and safe ice to absorb the tracks of sled dogs and snowmobiles’. Those changes deeply reshape the daily life and the ability to rely on traditional activities – hunting, short-distance movements, etc. – for people living in small settlements in Greenland. This also redesigns relationships between Greenland’s inhabitants and polar bears, whose behavior is affected by those sea-ice conditions. Available data about climate change in the Arctic does not provide adequate and accurate temporal and spatial community-scale knowledge to capture local realities and narratives in their dynamic dimensions as they pertain to situated experiences of resilience. Addressing this profound disconnectedness between the framing of scientific knowledge on climate change and community-embedded knowledge, needs and concerns, we mobilize long-duration fieldwork to underline salient criteria of changing sea-ice conditions for community-members in Ittoqqortoormiit and Uummannaq. The narrative approach we developed challenges the exclusivity of the science framing of climate change and opens up space for new ways of knowing and facing changing environment-human interactions. Hence, we will be in a position to discuss the potential for bridging climate science and local narratives of change in order to provide an understanding of resilience in the face of changing sea-ice conditions that is respectful of local values and people.
Periodicity of free oscillations for a finite ice column
Daniel Moreno, Marisa Montoya, Alexander Robinson, Jorge Alvarez-Solas
Corresponding author: Daniel Moreno
Corresponding author e-mail: danielm@ucm.es
Here we refine the classical analysis of free oscillations in an ice sheet by analytically solving the thermal evolution of an ice column. In so doing, we provide analytical solutions to the one-dimensional Fourier heat equation over a finite motionless ice column for a general boundary condition problem. The time evolution of the temperature profiles appears to be strongly dependent on the column thickness L and largely differs from previous studies that assumed an infinite column thickness. Consequently, the time required for the column base to thaw depends on several factors: the ice column thickness L, the particular initial temperature profile and the boundary conditions. This timescale is classically considered to be the period of a binge-purge oscillator. Our analytical solutions exhibit a broad period range for medium-size thicknesses. Furthermore, the particular values of the prescribed temperature at the top of the column become irrelevant in the limit L → ∞, thus retrieving the reference value of ~7000 years previously estimated for an idealised infinite domain. However, the periodicity remains sensitive to the vertical temperature gradient even for large L values. These results ultimately yield a common framework in which internal free and externally-driven oscillations meet as a result of a fundamental variable L that inherently accounts for the nature of both mechanisms.
María-José Iriarte-Chiapusso, Miren Ayerdi, Naroa Garcia-Ibaibarriaga, Arantzazu Pérez-Fernández, Aritza Villaluenga, Jon Arrizabalaga, Lide Lejonagoitia, Alvaro Arrizabalaga
Corresponding author: María-José Iriarte-Chiapusso
Corresponding author e-mail: mariajose.iriarte@ehu.eus
The history of humanity has been, and is, linked to the climatic and environmental dynamics of the planet. In this communication, we expose state of the art on how the climatic variability during the last glacial period manifests in the western sector of the north of the Iberian Peninsula (from the western Pyrenees of Navarre to Galicia). This territory presents a complex and outstanding biogeographic diversity in which the succession of stadial and interstadial events unequally affected the different coexisting biocenosis. In addition, throughout this period, the territory was occupied by two human species: Neanderthals and modern humans (Homo neanderthalensis and Homo sapiens). For this regional framework, we have much information for the period. This comes from the interdisciplinary investigations carried out, both in archaeological sites and in deposits of non-anthropic origin (such as peat bogs, lakes, marshes, wetlands, and trap-chasms). Despite the limitations inherent to the different types of deposits and to the analytics themselves (absence of sequences that comprise the entirety of the last glacial period, paleoenvironmental and/or stratigraphic hiatus, limitations of dating systems, geographic ‘gaps’ of information, etc.), we have interesting and very varied information. We know in great detail, especially for the period between 45 000 and 10 000 cal BP, how these human populations adapted to changing environmental conditions, what availability of plant and animal resources they had and how they occupied and moved through this territory. In its broadest sense, culture is the human instrument that allows adaptations and mechanisms of all kinds to be implemented (such as fire control, footwear, clothing, or weapons and tools) in a hostile environment.
Drivers behind international adaptation aid for mountain regions
Linda Rivera Macedo, Simon Keith Allen, Veruska Muccione, Markus Stoffel
Corresponding author: Linda Rivera Macedo
Corresponding author e-mail: lriveramacedo@gmail.com
Climate change adaptation in mountains is becoming an important area of interest due to mountains’ global importance in providing key ecosystem services and because of the increasingly evident effects of climate change. Glacier retreat and mountain permafrost degradation are two of the main observed climate change’s impacts in mountains, in particular in the cryosphere. The impact of these effects will not only be limited to natural hazards, but they will have negative effects across various sectors, such as energy, mines, cultural tourism and recreational. However, little attention has so far been paid to study adaptation in mountains and financial flows of aid to these regions. Moreover, the IPCC recently confirmed that observed adaptation is being unequally distributed across regions. Against this background, the objective of this study is to obtain an understanding of the ‘traditional’ determinants of international aid allocation (need, merit and donor interest) in the context of mountain adaptation aid, and to evaluate to what extent these determinants influence the adaptation aid allocation to mountainous countries. To answer this, a newly compiled data set is created to identify multilateral and bilateral adaptation projects and programmes directed towards 25 mountainous countries for the period 2011–19. The selection of mountainous countries was based on the percentage of mountain coverage in accordance with the UNEP-WCMC mountains classification, and the recurrence of hydro-meteorological events registered between 1984 and 2014. Then, a descriptive statistical analysis is used to assess, to what extent, vulnerability to climate change, readiness to climate change (based on the ND-GAIN Indices) and donor self-interest contribute to international adaptation aid allocation to countries located in the mountain regions. Based on our results, we identify shortcomings and challenges around how climate adaptation funding is distributed to mountainous regions to bridge the gap between science and decision making.
Snow and glacier melt simulation of Patsio glacier, western Himalaya, using a temperature index model for 2016 and 2017
Thupstan Angchuk, AL Ramanathan, Arindan Mandal, Mohd Soheb, Sarvagya Vatsal
Corresponding author: Thupstan Angchuk
Corresponding author e-mail: thups001@gmail.com
Meltwater from snow and glaciers is an important resource that plays a significant role in the socio-economic sustainability of the downstream regions. Snow and glacier melt rates are essential parameters for hydrological modelling studies. In this study degree-day factor (DDF) for various components (snow, ice, and debris-covered ice) has been estimated using field measurements and in-situ meteorological dataset from the Patsio glacier, Himachal Pradesh, western Himalaya. DDFs integration with air temperature has been used to run a classic Temperature Index Model to estimate the melt for two hydrological seasons (2016 and 2017). DDFs for snow, ice, and debris-covered ice around the automatic weather station location (5050–5100 m a.s.l.) were 8.3, 11.56 and 6.9 mm d–1 °C–1 respectively. The ablation was simulated at every 50 m elevation range by applying the respective DDFs and temperature lapse rate. The calculated DDFs are comparatively higher than other observed DDFs from the Himalayas except a few. However, we obtained a good agreement with simulated results and field observations with RMSE of around 0.14 for snow and 0.30 for ice. A temporary discharge station was set up at a distance of about 1.75 km downstream of the glacier terminus during ablation seasons. In 2017, an automatic water level recorder was installed, from 10 August 2017 to 15 September 2017. Diurnal variation analysis shows the peak discharge observed during the noontime, which corresponds well with the air temperature (Tair) and solar radiation. A negligible lag between the discharge and Tair has been observed during the measured period probably due to no storage characteristics and well-developed channels. Overall, this study shows meteorological parameters, especially air temperature plays a crucial role in governing the ablation of the Patsio glacier. However, high DDFs observed on this glacier suggest higher sensitivity to any change in temperature.
Patricia Muñoz Marzagon, Sérgio Henrique Faria
Corresponding author: Patricia Muñoz Marzagon
Corresponding author e-mail: patricia.munoz@bc3research.org
Glaciologists have been studying the microstructure of polar ice cores for decades to understand the dynamics of ice sheets, as well as the formation and integrity of ice-core paleoclimate records. Recent methodological and technological advances have enabled the production of high-quality images, which facilitate the study of ice microstructural changes caused by deformation. However, many aspects of the recovery and recrystallization mechanisms of ice and firn at the microscopic scale are still unknown. With the aim of better understanding these mechanisms, in this work we investigate the microstructure of shallow, polycrystalline bubbly ice through digital crystallographic and statistical analysis of high-resolution micrographs of ice sections extracted from the upper hundreds of metres of the EPICA-DML ice core. Specifically, we begin by reproducing Faria’s analysis of the spatial and directional distributions of slip bands from micrographs of this core, after which he proposed the hypothesis of ‘microstructural fading memory’. This hypothesis has been put forward as a possible explanation for the unexpected and depth-dependent behaviour of the spatial and directional distributions of slip bands in shallow polar ice. After repeating his analysis, we compare the results of both investigations to estimate reproducibility by determining the main sources of uncertainty and error. Finally, we analyse further micrographs of the same ice core, corresponding to different depths than those previously analysed by Faria, to ultimately test his hypothesis of ‘microstructural fading memory’.
The response of the Antarctic Ice Sheet to the PlioMIP2 climatic fields
Javier Blasco, Ilaria Tab, Daniel Moreno, Jan Swierczek-Jereczek, Antonio Juarez, Sergio Perez, Jorge Alvarez Solas, Alexander Robinson, Marisa Montoya
Corresponding author: Javier Blasco
Corresponding author e-mail: jablasco@ucm.es
Sea-level rise is one of the biggest threats that humankind faces due to climate change. The Antarctic Ice Sheet (AIS) plays a crucial role, as it is the largest ice sheet on Earth, and hence the largest potential contributor to sea-level rise. However, its response to future warming scenarios remains highly elusive due to uncertainties in the modeling of physical processes as well as structural dependencies. Past warm scenarios can help to elucidate this uncertainty as we can obtain information such as the sea-level standings and global temperatures. The Pliocene Model Intercomparison Project Phase 2 (PlioMIP2) is a co-ordinated international climate modeling initiative to study and understand climate and environments of the mid-Pliocene warm period (mPWP, 3.3–3.0 million years ago). During this period, CO2 levels were comparable to present-day (PD, 350–450 ppmv) but global mean temperatures were 2.5–4.0 degrees warmer and sea-level standing 15–20 m higher than PD, pointing to reduced continental ice sheets. In fact, the modern Greenland Ice Sheet was starting to form, hence the AIS was the only existing continental-size ice sheet. PlioMIP2 has collected 15 climate outputs from 11 different general circulation models. Here we use these model outputs to force offline a three dimensional higher-order ice sheet model in the Antarctic domain. Our aim is to investigate how the AIS responds to these different climatic fields to pinpoint their most significant climatic and topographical discrepancies.
The agency of melting glaciers
Halvor Dannevig, Tone Rusdal
Corresponding author: Halvor Dannevig
Corresponding author e-mail: hda@vestforsk.no
Perennial snow and ice will gradually disappear from many regions in the Arctic and sub-Arctic parts of Scandinavia. Glaciers and perennial snow fields are important landscape features and venues for tourism activities and mountaineering, have importance for place identity and hold symbolic and cultural significance for nearby communities. In this paper we present findings from a study into how guides, tourists and other local tourism actors perceive climate and environmental change and impacts on local communities and the tourism industry. Melting glaciers have become one of strongest symbols of global climate change, instigating last chance tourism as well as rallying cries for climate action from activists. In this sense retreating glaciers act as charismatic entities, appealing to the publicְ’s feelings and imagination. The melting cryosphere is also subjects for scientific enquiry, providing the very knowledge that are needed to establish its rate of decline and interlinkages and feedbacks with other natural and human systems. Climate change is a phenomenon that is notoriously hard to connect with emotionally for most people, as it is based on highly abstract models of reality that do not connect with most people’s personal experiences and perceptions. Melting glaciers can thus serve as boundary object by the properties they have as charismatic entities, which allows tour guides or activists to raise awareness about climatic and environmental change or push for climate action. The glaciers serve to reconcile different knowledge systems, allowing for co-existence of emotions, imaginaries and scientific rationality. By interviews, workshops and surveys in local communities surround two of the major ice caps in Norway – Jostedalsbreen and Folgefonna – and in Svalbard in the high Arctic, we find that the immediate consequences of the disappearing snow and ice are manageable. Tourism actors have a high adaptive capacity, and tourists indicate that they would still visit the glacier-destinations. But these findings can overshadow more subtle impacts of the melting ice. By drawing on theories both from human geography and science technology studies, we show how the melting glaciers display non-human agency by inspiring guides and other tourist professionals to influence tourists’ awareness and concern about climate change and sustainability.
Daniel Richards, Sam Pegler, Sandra Piazolo, Nicolas Stoll, Ilka Weikusat
Corresponding author: Daniel Richards
Corresponding author e-mail: d.h.richards@leeds.ac.uk
Accurately predicting and reconciling measured ice fabrics is fundamental to understanding deformation processes and flow characteristics in ice sheets. Here we explain our recently developed ice fabric evolution model (SpecCAF) and apply it to directly compare the model predictions with observational fabric data from an ice core drilled in an active ice stream, the Northeast Greenland Ice Stream (NEGIS). SpecCAF has been shown to agree with experimentally produced fabrics from both compression and simple shear, over a range of temperatures, including reproducing detailed features such as secondary clusters. The model incorporates the leading-order effects of migration and rotational recrystallization, and basal-slip deformation to provide an efficient and highly resolved description of the evolution of the orientation density of ice fabric. We apply this model to predict the fabric evolution of the East Greenland Ice Core Project (EGRIP) ice core drilled through a location on NEGIS with a surface velocity of 55 m a–1. We show that the model can account fully for the observed girdle/horizontal maxima fabric pattern perpendicular to the flow direction. As the model is based primarily on the effects of deformation and recrystallization through dislocation creep, our results thus confirm for the first time that, for the ice stream modelled, these processes fully account for the observations. We find that the model matches natural data best if the boundary condition of full slip at the base of the ice sheet is applied, providing a new means to constrain the basal condition of the ice sheet. This confirms independently high levels of slip at NEGIS. By reducing the influence of rotational recrystallization on fabric evolution in the model, the model predicts the fabric pattern and orientation measured at EGRIP to good approximation, with the correct fabric strength. This suggests that the rate of rotational recrystallization may be primarily strain-rate and, in turn, stress dependent. SpecCAF, and the methodology shown here, present a new tool for wider application to ice core locations in Greenland and Antarctica.
Black carbon in snow on Icelandic glaciers
Outi Meinander
Corresponding author: Outi Meinander
Corresponding author e-mail: outi.meinander@fmi.fi
Black carbon (BC) is a short lived climate forcer (SLCF) which can accelerate snow and ice melt via the ice-albedo feedback. when it deposits on snow and ice surfaces. As climate is warming, glaciers in Iceland are declining. Our investigation asks What role does black carbon play in the cryospheric melt in Iceland? For the purpose we have collected and analyzed BC in snow on glacier and on land and ice in water as well as water samples in Iceland. Our results have shown highly variable BC concentrations in these samples and revealed locations with no BC (0 ppb) as well as higher concentrations (>30 ppb) on snow close to anthropogenic sources.
Assessing sustainability strategies in the oil and gas sector through an iceberg view
Jaime Menendez
Corresponding author: Jaime Menendez
Corresponding author e-mail: jaime.menendez@orkestra.deusto.es
Achieving greenhouse gases (GHG) emissions reduction targets requires the design and application of policies and measures that are able to involve as many stakeholders as possible, including business and industry. This has been translated into a growing regulatory and market pressure for multinational companies, which are called to develop effective and realistic sustainability strategies in order to ease the transition to a decarbonized economy. However, there is also a growing social concern regarding the true convenience of many of these strategies, as some may lack ambition or could be used as marketing and greenwashing tools, rather than useful roadmaps to achieve sustainability activities. This study pays attention to oil and gas companies (O&G), which make up one of the main industries accused of greenwashing practices and obstruction of climate change mitigation measures. Following a case study methodology, this research focuses on a particular O&G company and assesses its annual sustainability reports published in the last four years by applying a combined analysis framework based on grey literature. Overall, this study found that there are relevant decarbonization activities (with a strong technological innovation approach) that the studied O&G company is carrying out, although they are being developed within a diversification context in which the use of fossil fuels and GHG emissions still remain as part of the core business. These findings suggest that O&G sustainability strategies need to be assessed with a comprehensive view, so activities with high potential of GHG emissions reduction are not separated from those that imply business as usual practices and, therefore, both ‘hidden’ positive or negative activities are clearly pointed out. Due to this, this work proposes to present the assessment of sustainability strategies in the O&G sector with a novel approach called the ‘iceberg perspective’, which may facilitate a correct and complete understanding of O&G sustainability strategies design. At the same time, the iceberg view could act as a powerful symbolic linkage between climate change impacts and O&G activities in order to raise awareness about this issue. Avenues for further research may include improving this iceberg view and applying it in different case studies, which might be particularly significant regarding O&G companies that have exploration and production activities in the Arctic.
White Wanderer Requiem: music inspired by the cryoseismology of the last days of iceberg B15A
Sean Gallero, Petra Bachmaier, Katherine Young, Douglas MacAyeal
Corresponding author: Douglas MacAyeal
Corresponding author e-mail: drm7@uchicago.edu
Over the period of 2005/6 a seismometer was deployed on tabular iceberg B15A, which was bumping and grinding its way North along the western coast of the Ross Sea, Antarctica. This iceberg, a piece of what was arguably the largest iceberg ever witnessed at the time, was the source mechanism for a cryoseismic signal called ‘iceberg tremor’. More than 10 years beyond the seismically active break-up of B15A, artists from Luftwerk in Chicago obtained the seismic data and converted it (by up-scaling the frequencies into audible range) into a haunting musical requiem that portrays the seriousness of ice in a sustainable society. The music has been featured in several ‘sound installations’ in outdoor public venues around Chicago, and has inspired the composing of a piece performed by a musical ensemble in the Gehry-designed Pritzker Pavilion of Chicago in early 2020. In the presentation to be made here, the interaction between the science and the art, between the scientists and the artists, will be described. The art itself will not be performed or displayed, but rather links to where viewers can see and hear records of the performances will be made available. In essence, this presentation will document a successful interaction between glaciological science and the arts with the intention of helping to facilitate future ventures of this nature. Note: if there is a display venue which presents glaciology/arts connections where other artists make presentations, this poster can be modified to adapt to a more performance-oriented sound installation.
The assessment of geological hazards in a remote Karakoram valley (Hushe): is it feasible?
Ane Zabaleta, Arantza Aranburu, Eñaut Izagirre, Jesus Angel Uriarte, Iñaki Antiguedad
Corresponding author: Iñaki Antiguedad
Corresponding author e-mail: inaki.antiguedad@ehu.eus
The Hushe River basin (Ghanche District, Gilgit-Baltistan) is located in the SE of the Central Karakoram National Park in Pakistan, south of the Baltoro glacier, between the Karakoram Batholith and the Main Karakoram Thrust. The area exhibits an extreme topography (elevations from 2441 to 7821 m) and a complex interaction among erosion, transport and sedimentation processes. The valley is north–south oriented with an area of 1230 km2. The relief is dominated by glacial high mountains on the upper level, and valleys with glacio-fluvial and nivo-fluvial regimes on the mid and lower levels. There are 153 glaciers, with a total glacial area of 402 km2 in 2019, approximately one third of the basin. The valley communities (13 000 inhabitants, over half of them women, in 12 villages) have settled on the flat alluvial fans at the exit of the lateral valleys existing by the 42.4 km of the Hushe River. Subsistence farming is the predominant activity, and agriculture and the production of hydropower are mainly dependant of the freshwater supply to the river system. The present study was part of a development cooperation project (Basque Government) to increase the resilience of the Hushe Valley inhabitants to the hydro-geomorphological processes that pose a threat. To that aim, we focused on identifying and mapping the landforms of the Hushe Valley (below 3400 m), also on trying to involve local stakeholders. Paraglacial processes are the most important drivers of recent (and probably future) landscape evolution. Common geohazards in the valley include river floods, mud/debris flows, rock falls and landslides that caused village destruction and loss of lives in recent years. In this context, two monitoring approaches were proposed: an observational network for the monitoring of rockfalls and a network for the continuous monitoring of hydrological parameters. In both cases, local actors were involved and provided with the required resources and instructions. Unfortunately, none of these lines of action has been fruitful to date. Surveys conducted among the local inhabitants show the low importance given to geohazards. The social objectives of geohazard research in mountain areas should enable researchers in the region to generate scientific evidence and social actors at the local level to use that evidence to increase the resilience of the local communities, improve their living conditions and face future scenarios of change with sustainability guarantees.
Development of a technique of immersion microscopy on ice
Bittor Muniozguren Arostegi, Patricia Muñoz Marzagon, Sérgio Henrique Faria
Corresponding author: Bittor Muniozguren Arostegi
Corresponding author e-mail: bittor.muniozguren@gmail.com
Despite being called the blue planet, fresh water constitutes just a small fraction of all water available on Earth. About three quarters of this fresh water is stored as ice and snow all around the globe, mainly on glaciers and on ice sheets at the poles. This perenial ice contains internal structures and impurities that serve as an archive of the climate history of the planet. Nevertheless, the integrity of this record is conditioned by the dynamics of ice. Ice microstructures are constantly under the influence of the ice inner flow ( also called ‘creep’), which also influences the ice melting and the rise of sea level. In order to study the marks that the ice creep leaves on its microstructure, optical microscopy is often used. The aim of this work is to assess the viability of oil immersion microscopy on the study of ice microstructures. Immersion microscopy, which consists of using an oil between the objective lens and the specimen, is a technique well-developed for the study of diverse materials, but it has so far not been explored for the study of ice. As described here, this technique might bring certain advantages and challenges for the study of ice microstructures.
The Monte Perdido glacier and how climate change has affected its disappearance
Maria Díez
Corresponding author: Maria Díez
Corresponding author e-mail: marietadzgllo@gmail.com
The Monte Perdido glacier, which is located in the Marboré Cirque, southeast of the Central Pyrenees, on the north face of the Monte Perdido peak, has undergone many changes from the Little Ice Age until now. This research has focused on seeing which have been the main causes of these changes that it has undergone, such as the thaw. Climate change due to human activity has played a relevant role in this thaw, as it has been observed that the thaw has increased rapidly since the beginning of the Industrial Revolution. Therefore, a directly proportional relationship has been established.
Modelling of iceberg ensemble drift during Heinrich events, towards a continuous-diversity model
Ion Ander Goikoetxea, Gabriel Alejandro Lopez, Sérgio Henrique Faria
Corresponding author: Ion Ander Goikoetxea
Corresponding author e-mail: nerogoiko@gmail.com
Icebergs are large blocks of ice of different shapes and sizes, ranging from several cubic meters to millions of cubic metres. They are formed by calving (i.e. separation of a block from a larger ice mass) from tidewater glaciers and ice shelves. The drift of icebergs is relevant for a number of problems, ranging from ship traffic and offshore infrastructure safety to marine ecology and paleoclimate. In particular, marine paleoclimate records reveal massive discharges of icebergs into the North Atlantic during climatic phenomena called Heinrich Events. Nevertheless, the iceberg drift phenomenon has been a challenging problem for a long time, in part due to the issues related to its geometry and the diverse ways it may interact with winds and ocean currents during its voyage until complete decay. Here we revisit the continuum model proposed by Clarke & LaPrairie (2001) for the drift and decay of an armada of icebergs throughout the North Atlantic during a Heinrich Event. Our objective is to check the foundations of the Clarke–LaPrairie model, providing a solid theoretical basis for deeper interpretation and future developments. To this aim, we use the Theory of Continuous Diversity, which is an extension of classical mixture theory to an infinite number of constituents. Among other results, we show how the ocean–iceberg interaction gives rise to a diffusive effect on the drift of the armada, and we derive from first principles a thermodynamic expression for the diffusion coefficient associated to this effect. We also explore the strengths and weaknesses of the model and deepen our analysis of the physical interpretation of the equations and the particularities of the application of the concept of Continuous Diversity on them.
Marcela Brugnach, Sergio Faria
Corresponding author: Marcela Brugnach
Corresponding author e-mail: marcela.brugnach@bc3research.org
The science of glaciology has for a long time focused on the study of the physics of ice and glaciers. Doing so has allowed to greatly expand our knowledge and understanding of them. Now we know about their behaviours and dynamics, knowledge that served to better understand the function of these glaciers in different geographies, categorized them and further study them. Knowledge that beyond the scientific domain, proved to be tremendously useful for climate change and policy (e.g. core knowledge in documents like IPCC reports). However, in the study of glaciology much less has been said regarding the links and meanings that exist between glaciology and society. As if the study of these bodies of ice were disconnected from society. In this presentation we want to address the interdependencies that exist between glaciologists and society. We argue that even when glaciology may seem very specialized and far away from our daily affairs, it is actually not separated and detached of our own subjective experiences and actions.
Soundart from the North Pole
Txema Agiriano
Corresponding author: Txema Agiriano
Corresponding author e-mail: txema@musicaexmachina.com
Since 2002, the international experimental art festival MEM has been showing projects in Bilbao where art and technology converge. This is the case of Computersignale, a project directed by the professor and artist Hannes Rickli, supported by the Zürcher Hochschule der Künste, developed under the sea in Spitsbergen, 100 km from the North Pole. Artist Valentina Vuksic uses data from the RemOs1 (Remote Optical System) underwater station to create a sound art work.
Cryo-Raman microscopic investigations on ice cores from Casteret Ice Cave
Julene Aramendia, Jennifer Huidobro, Patricia Muñoz Marzagon, Nicolas Gonzalez, Sergio H. Faria, Miguel Bartolome, Ana Moreno, Juan Manuel Madariaga
Corresponding author: Julene Aramendia
Corresponding author e-mail: julene.aramendia@ehu.eus
Raman spectroscopy is a molecular non-destructive analytical technique that provides molecular and structural information. Considering its non-destructive character, it is considered a very appropriate technique for unique samples. Ice-core specimens are sensitive and singular samples for which Raman spectroscopy is an adequate technique. Temperature stages allow also the analysis of ice samples without the need of losing the sample structure and changing its physical properties. They can be used for Raman microscopy providing cryo-Raman results. By these means, micro-structure of the ice and the composition of the inclusions present inside can be studied. To demonstrate the potential of the approach, different ice cores deriving from Casteret Ice Cave were analyzed by means of cryo-Raman microscopy. Ice caves are rock-hosted caves containing perennial ice and/or snow. The Casteret (also known as Espluca Negra) Ice Cave is one of the best-known fossil-ice caves in the Pyrenees, located in the Monte Perdido Massif. It consists of a large gallery over 120 m long and several meters wide that connects its two entrances at 2710 m and 2690 m. It is a clear example of a dynamic cave with congelation ice, following the Luetscher–Jeannin classification. The Casteret ice samples showed plenty of inclusions inside the ice matrix, whose characterization could provide information about the evolution of the climate, geologic context and human impact through time. The approach consisted of cutting a subsample of the ice core (12 × 12 × 8 mm) suitable for the Linkam THMS600 temperature-controlled stage. This stage allows a cooling temperature down to –195°C. For this work, it was set at –40°C before introducing the sample. The ice-core subsample was maintained at the mentioned temperature during the whole analysis. For the molecular analysis, an InVia Confocal Raman microscope provided with excitation lasers at 532, 785 and 633 nm, a CCD detector and a Leica confocal microscope, mounted with 5× 20×, 50× and 100× lenses, which allowed depth profile analyses to be performed, was used. Anatase, rutile, brookite, calcite, different carotenoids and others were detected in the inclusions. This could mean that the ice contained African dust samples and green algae that have been detected annually in the snow. The location traceability of the inclusions and the correlations among the detected compounds provided valuable information that will be discussed.
The Seligman Crystal Lecture: a history of challenges and advances in ice sheet modeling
Catherine Ritz
Corresponding author:Catherine Ritz
Corresponding author e-mail: catherine.ritz@univ-grenoble-alpes.fr
Ice-sheet modeling is an essential tool for assessing the future of sea-level rise in the context of climate change. There is a clear societal need to address this issue and I want to present here the evolution of this discipline to highlight all the progress made so far and suggest some perspectives. The ice- sheet models we use today are the result of nearly 50 years of research, which took off with the arrival of computers and numerical methods, whose impressive progress has subsequently allowed us to address many challenges. Several aspects will be presented: how the objectives of ice-sheet modeling, initially focused on paleoreconstructions, are now oriented toward sea-level projections. How the equations used in ice-sheet models have become increasingly sophisticated with the succession of approximations that first have been established for grounded ice, then for floating ice shelves, and finally for the transition zone between the two, which is the key issue in modeling grounding-line dynamics and the associated ice-sheet instability (MISI). All these developments have been subject to intercomparison experiments that have validated the different implementations. Another important step was the development of methods to take advantage of observations (especially remote sensing) with the introduction of assimilation, variational and statistically oriented methods, including Ensemble methods that allow to assess the uncertainty in projections. Throughout the presentation, the role of various initiatives that have greatly helped build the community and contributed to the progress of this discipline will be highlighted.
Benjamin Tejerina
Corresponding author: Benjamin Tejerina
Corresponding author e-mail: b.tejerina@ehu.eus
Forty years have passed since Paul Feyerabend’s ‘Science in a free society’ (1978) in which he denounced the surprising prestige of science in the West and its incompatibility with a democratic society. Since then, experiences based on the participation of citizens in scientific projects have not ceased to increase. But it would be wrong to think that this is a recent phenomenon, since the history of knowledge is full of cases in which personal interest and motivation have been the driving force behind innovation and scientific discoveries by people who did not have specialized training. The 20th century has been notable for multiplying examples of citizen collaboration with scientific experiments, health programs or as a source of information and data collection on issues of scientific interest. In the last five decades, scientific experiences based on the participation of citizens and non-scientific agents have continued to increase. However, scientific popularization and current technological facilities have placed this collaboration in a new dimension. Based on the study of several cases of citizen science, this contribution aims to analyze a variety of figures of collaboration between lay people and scientists, between ordinary knowledge and more specialized knowledge. The objective is threefold: first, to identify the figures of participation in order to explore the nature and characteristics of this form of collective action; second, to know what effects are produced by opening the doors of science to the active and regular participation of citizens in order to try to respond to the means, purposes, social impacts and resistance of this kind of collaboration between citizens and professional scientists; and third, some current debates on the participation of citizens in citizen science projects are presented. The study has consisted of the analysis of interviews with researchers who have led different scientific projects, as well as an extensive documentation of participatory experiences in citizen science activities.
Discovering the pastoral systems in Atlantic Pyrenees
Elena Galán
Corresponding author: Elena Galán
Corresponding author e-mail: elena.galan@bc3research.org
The objective of this paper is to offer the participants a close view of the human–natural environment of the Basque pastoral systems in the Pyrenees, relying on my own experience of taking care of a flock of 500 sheep and seven cows in the mountains of the common lands of Donibane Garazi. Free from catalogue-style or folkloric touristic approaches, my particular vision (situated as a non-Basque, from an urban family, professional shepherd) will provide basic information about the products of this system, main animal breeds, social organization and current threats to livelihoods that have adapted and survived for centuries.
Maialen Iturbide Martínez de Albéniz, Josipa Milovac, José Manuel Gutiérrez
Corresponding author: Maialen Iturbide Martínez de Albéniz
Corresponding author e-mail: miturbide@ifca.unican.es
The Interactive Atlas (IA) is a novel contribution of IPCC Working Group I (WGI) to the recently released Sixth Assessment Report. It is the result of 3 years of close collaboration between WGI and contributing authors from CSIC (Consejo Superior de Investigaciones Científicas), Universidad de Cantabria and the the technology-based company Predictia, supported by the Spanish government. The IA was conceived as a tool to support the assessment done in the AR6 WGI report, so it focuses on the key atmospheric and oceanic variables assessed in the chapters and provides users with an interactive online environment to visually explore and expand the main results of the report. In order to meet the requirements of various groups of end users (from scientific professionals to stakeholders, and the public in general), the IA includes both an advanced and a simple interface through which users can access a comprehensive set of global and regional climate information. Furthermore, the regional synthesis component of the IA provides different visualizations of the synthesis information on changes in climatic impact-drivers (CIDs) assessed in the Technical Summary and the Summary for Policymakers. The IA is based on open source software (the R based climate4R framework) and implements the FAIR data principles including reusability. The latter can be accomplished through the Atlas GitHub repository, which provides data and scripts behind the IA and includes well-documented Jupyter notebooks that users can execute directly through freely available online computational resources from BinderHub. In this presentation, we demonstrate the broad possibilities of the IA for a flexible spatial and temporal analysis of past, present, and future climate on a regional scale through different exemple cases.
Recent advances in cryospheric microbiology
Alexandre Anesio
Corresponding author: Alexandre Anesio
Corresponding author e-mail: ama@envs.au.dk
Glaciers and ice sheets were long believed to be sterile environments but, just like other large ecosystems (e.g. tropical forests, tundra), they are now widely recognized as one of the Earth’s biomes, teeming with life. This biome is also the most under-investigated on the planet from a biological and biogeochemical perspective, representing a new and exciting frontier in science. Home to large, naturally occurring communities of mostly microbes, glaciers and ice sheets host metabolically active organisms, interacting with each other. These processes represent more than just a minor curiosity of life under extreme conditions. On glacier and ice-sheet surfaces, microbes have been shown to alter physical and chemical characteristics of snow and ice with direct consequences for snow/ice solar-heating and amplified melt. During the summer ablation, the bare ice is largely dark, as it is colonized by pigmented ice algae. Biological growth of icebound algal cells can accumulate biomass high enough to cause albedo reduction between 12% and 21%, depending on the algal cell abundances. The impact of microbially mediated albedo effect is predicted to increase further with climate change, since a warming climate will further extend melt seasons. Furthermore, microbial activity and carbon fixation on ice surfaces can result in export of labile dissolved organic matter to downstream ecosystems.
Moving ice
Michael Bravo, Adriana Craciun, Sérgio Henrique Faria, Mark Jackson, Martyn Tranter
Corresponding author: Sérgio Henrique Faria
Corresponding author e-mail:sh.faria@bc3research.org
PANEL DISCUSSION. Scientific approaches to understanding the cryosphere – whether polar, mountainous, permafrost, sea, or extraplanetary – predominantly organize ice and snow as data. Ice is rendered knowable via modes of attention and techniques made possible by things like samples, cores, drones, satellites and models. Such approaches, fundamental and important though they are, nevertheless also shape glacial imaginaries and their geographical contexts in ways that often render ice as asocial and ahistorical. This matters for how the ethical and political demands of our environmental present are addressed. If we approach icy environments with knowledge shorn of social, historical, and cultural context, we risk generalizing ethical and political responses to challenges like anthropogenic melting and thawing in ways that neglect specificities of place, people, and the processes driving glacial change. But, does glaciology have an ethical or political responsibility to these contexts? Indeed, how might we define glaciology’s special responsibilities to society? The unprecedented acceleration of glacial retreat and melting means that the discipline of glaciology has acquired a special status as expert spokesmen and spokeswomen for ice. And yet, arguably, the challenge in discussing glaciologists’ social responsibility is that the significance of their subject becomes unbounded. Peoples on every continent inhabit ecologies defined by their proximity to present and past ice formations, whether glaciers, ice sheets, permafrost, or sea ice. To explore the obligations and limits of professional responsibility is also to ask in what ways glaciological knowledge producers have a social responsibility to both the diversity of icy worlds and to the ways by which icy knowledge is generated? Who counts as a glacial knowledge maker? How is what counts as glacial knowledge produced and shared? Who has access to it? If, like the earth sciences as a whole, glaciology has a long association with debates about moral responsibility, the question we invite glaciologists to consider is less one of where and how to begin, but rather to share in reflecting on which social needs and hazards to be allied with. Chaired by physical and social scientists, together with invited guests, the panel invites conference participants to reflect upon and share how they navigate the ethics, politics and perhaps even aesthetics of making glaciological science.
The Global Pole: cartographic visions of the polar ice and humanity
Michael Bravo
Corresponding author: Michael Bravo
Corresponding author e-mail: mb124@cam.ac.uk
This may be the century of the North Pole. For centuries the pre-eminent symbol of the Arctic, today it epitomizes the Arctic’s regional significance for the whole globe. There is a paradox that the North Pole seems to have geopolitical value, and yet with the earth’s axis spinning beneath it, it is timeless. Viljhamur Stefansson, the Arctic’s foremost philosopher, understood this paradox better than anyone. In this lecture, I will for the first time explain why Stefansson celebrated the icy poles in the middle of the Arctic Ocean. Surprisingly, this enabled Stef to unlock the question of what makes the Arctic habitable, and why the North Pole is crucial for understanding our relationship to the planet we call home in the 21st century.
IPCC: past, present and future
Sérgio Henrique Faria
Corresponding author: Sérgio Henrique Faria
Corresponding author e-mail: sh.faria@bc3research.org
PANEL DISCUSSION. The Intergovernmental Panel on Climate Change (IPCC) has been the lighthouse of global and regional climate policymaking for decades. In the current, Sixth Assessment (AR6) Cycle, the IPCC has been producing an unprecedented number of reports, including three Special Reports, a Methodology Report, and the voluminous Sixth Assessment Report consisting of three Working Group Contributions and a Synthesis Report. This reflects IPCC’s continual evolution and adaptation to the world’s needs with the rising climate crisis. As the AR6 cycle comes to an end, the world has already warmed 1.1°C and the Paris Agreement ultimate goal of limiting global warming to 1.5°C by the end of the century is becoming increasingly out of reach. The next IPCC cycle, AR7, will likely conclude around 2030, in a time when the decisions to limit – or not – warming to 1.5°C will already have been made. This raises a number of questions, such as: What may change in the next IPCC cycles (AR7, AR8, etc.) in a world where the best futures could be getting crossed off the list of possibilities? What could be IPCC’s next steps to climate communication to society, now that the AR6 has already declared it to be indisputable that human activities are causing climate change? What will be the role of the cryosphere in the next IPCC cycles? These and other related questions will be discussed with the audience in this panel.
Transdisciplinary glaciology and social responsibility
Sérgio Henrique Faria
Corresponding author: Sérgio Henrique Faria
Corresponding author e-mail: sh.faria@bc3research.org
PANEL DISCUSSION. The adjective ‘transdisciplinary’ has become a buzzword echoed by researchers and funding agencies alike, often invoked for the mere purpose of fancying up their projects and programmes. This is one reason why its definition is still disputed. Here we adopt Repko’s (2012) definition of ‘transdisciplinary’ as that which is at once between the disciplines, across different disciplines, and beyond all disciplines, where ‘discipline’” stands not only for academic fields but also for stakeholder views. Performing true transdisciplinary research is in practice a nightmare, not only because of its intrinsic complexity but above all because funding agencies are often not prepared or willing to evaluate and support truly transdisciplinary projects. Nevertheless, it is widely recognized that transdisciplinary research is crucial for the solution of complex climatic and environmental problems. On this panel we will discuss how true transdisciplinarity may be achieved, how valuable it may be for glaciology, and which social implications and responsibilities it may entail.
The southernmost natives of the world, who painted their faces to look at the glaciers
Enaut Izagirre
Corresponding author: Enaut Izagirre
Corresponding author e-mail: enaut.izagirre@ehu.eus
The Yaghan people, considered the southernmost indigenous people in the world, once paddled the remote and isolated channels and fjords of the Tierra del Fuego archipelago in the southernmost part of South America. The Yaghans inhabited this region for more than 6000 years and developed a deep connection with the environment through hunting, fishing, and living between the sea and the mountains. The Cordillera Darwin Icefield covers an area of 1760 km2 with a significant number of glaciers that descend to sea level, becoming important landmarks and iconic geographic elements of the Fuegian Channels landscape. This work focuses on the study of the indigenous relationship to the glaciers (táun in the Yaghan language) by reviewing anthropological studies and the testimony of some of the last direct descendants who lived in the Beagle Channel area until recently. Our work shows that Yaghan culture revered and respected ice and glaciers, and associated specific rituals and cultural behaviours with them.
Ibai Ieltxu Rico Lozano
Corresponding author: Ibai Ieltxu Rico Lozano
Corresponding author e-mail: ibai.rico@ehu.eus
Glaciers are iconic elements of the high mountain landscape and represent a natural and cultural heritage of great interest to local populations, tourists and visitors, and the culture associated with mountain activities. Glaciers in the Pyrenees have suffered accelerated surface loss since the 1980s, and their disappearance may have consequences for mountain communities and tourist attractiveness. This paper analyses the current contribution of glaciers to society (Nature’s Contributions to People) and how the possible disappearance of glaciers in 2050 could affect perceptions of the mountain landscape, related activities, and tourism.
The cryosphere in the IPCC sixth assessment cycle
Valérie Masson-Delmotte
Corresponding author: Valérie Masson-Delmotte
Corresponding author e-mail: valerie.masson@lsce.ipsl.fr
Created in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP), the Intergovernmental Panel on Climate Change (IPCC) provides governments at all levels with scientific information that they can use to develop climate policies. This information is offered through regular assessments of the scientific basis of climate change, its impacts and future risks, and options for adaptation and mitigation. The IPCC is now in its sixth assessment cycle, in which the IPCC is producing the Sixth Assessment Report (AR6) with contributions by its three Working Groups and a Synthesis Report, three Special Reports, and a refinement to its latest Methodology Report. The Working Group I contribution to the Sixth Assessment Report, Climate Change 2021: The Physical Science Basis was released on 9 August 2021. It addresses the most up-to-date physical understanding of the climate system and climate change, bringing together the latest advances in climate science, and combining multiple lines of evidence from paleoclimate, observations, process understanding, global and regional climate simulations. It shows how and why climate has changed to date, and the improved understanding of human influence on a wider range of climate characteristics, including extreme events. There is a greater focus on regional information that can be used for climate risk assessments. The cryosphere is addressed in most of the 13 chapters of the Working Group I report, including a dedicated Chapter 9: Ocean, Cryosphere and Sea Level Change.