Academic literature on the topic 'Recent past and future sea-level changes, mountain glaciers'

Abstract Global sea level rise due to the thermal expansion of the warming oceans and freshwater input from melting glaciers and ice sheets is threatening to inundate low-lying islands and coastlines worldwide. At present the global mean sea level rises at 3.1 ± 0.7 mm yr−1 with an accelerating tendency. However, the magnitude of recent decadal sea level trends varies greatly spatially, attaining values of up to 10 mm yr−1 in some areas of the western tropical Pacific. Identifying the causes of recent regional sea level trends and understanding the patterns of future projected sea level change is of crucial importance. Using a wind-forced simplified dynamical ocean model, the study shows that the regional features of recent decadal and multidecadal sea level trends in the tropical Indo-Pacific can be attributed to changes in the prevailing wind regimes. Furthermore, it is demonstrated that within an ensemble of 10 state-of-the-art coupled general circulation models, forced by increasing atmospheric CO2 concentrations over the next century, wind-induced redistributions of upper-ocean water play a key role in establishing the spatial characteristics of projected regional sea level rise. Wind-related changes in near-surface mass and heat convergence near the Solomon Islands, Tuvalu, Kiribati, the Cook Islands, and French Polynesia oppose—but cannot cancel—the regional signal of global mean sea level rise.

The dynamics of ocean-terminating outlet glaciers are an important component of ice-sheet mass balance. Using satellite imagery for the past 40 years, we compile an approximately decadal record of outlet-glacier terminus position change around the entire East Antarctic Ice Sheet (EAIS) marine margin. We find that most outlet glaciers retreated during the period 1974–1990, before switching to advance in every drainage basin during the two most recent periods, 1990–2000 and 2000–2012. The only exception to this trend was in Wilkes Land, where the majority of glaciers (74%) retreated between 2000 and 2012. We hypothesize that this anomalous retreat is linked to a reduction in sea ice and associated impacts on ocean stratification, which increases the incursion of warm deep water toward glacier termini. Because Wilkes Land overlies a large marine basin, it raises the possibility of a future sea level contribution from this sector of East Antarctica.

This paper is meant to study the apocalyptic scenario of the at the perspectives of the Great Acceleration. the apocalyptic scenario is not a pure imagination of the literature works. Instead, scientific evidences are in favour of dramatic change in the climatic conditions related to the climax of Man actions. the modelling of the future climate leads to horrible situations including intolerable temperatures, dryness, tornadoes, and noticeable sear level rise evading coastal regions. Going far from these scientific claims, Homo Sapiens Sapiens extended his imagination through the Climate-Fiction (cli-fi) to propose a dramatic end. Climate Fiction is developed into a recording machine containing every kind of fictions that depict environmental condition events and has consequently lost its true significance. Introduction The Great Acceleration may be considered as the Late Anthropocene in which Man actions reached their climax to lead to dramatic climatic changes paving the way for a possible apocalyptic scenario threatening the existence of the humanity. So, the apocalyptic scenario is not a pure imagination of the literature works. Instead, many scientific arguments especially related to climate change are in favour of the apocalypse1. As a matter of fact, the modelling of the future climate leads to horrible situations including intolerable temperatures (In 06/07/2021, Kuwait recorded the highest temperature of 53.2 °C), dryness, tornadoes, and noticeable sear level rise evading coastal regions. These conditions taking place during the Great Acceleration would have direct repercussions on the human species. Considering that the apocalyptic extinction had really caused the disappearance of many stronger species including dinosaurs, Homo Sapiens Sapiens extended his imagination though the Climate-Fiction (cli-fi) to propose a dramatic end due to severe climate conditions intolerable by the humankind. The mass extinction of animal species has occurred several times over the geological ages. Researchers have a poor understanding of the causes and processes of these major crises1. Nonetheless, whatever the cause of extinction, the apocalyptic scenario has always been present in the geological history. For example, dinosaurs extinction either by asteroids impact or climate changes could by no means denies the apocalyptic aspect2.At the same time as them, many animal and plant species became extinct, from marine or flying reptiles to marine plankton. This biological crisis of sixty-five million years ago is not the only one that the biosphere has suffered. It was preceded and followed by other crises which caused the extinction or the rarefaction of animal species. So, it is undeniable that many animal groups have disappeared. It is even on the changes of fauna that the geologists of the last century have based themselves to establish the scale of geological times, scale which is still used. But it is no less certain that the extinction processes, extremely complex, are far from being understood. We must first agree on the meaning of the word "extinction", namely on the apocalyptic aspect of the concept. It is quite understood that, without disappearances, the evolution of species could not have followed its course. Being aware that the apocalyptic extinction had massacred stronger species that had dominated the planet, Homo Sapiens Sapiens has been aware that the possibility of apocalyptic end at the perspective of the Anthropocene (i.e., Great Acceleration) could not be excluded. This conviction is motivated by the progressive defaunation in some regions3and the appearance of alien species in others related to change of mineralogy and geochemistry4 leading to a climate change during the Anthropocene. These scientific claims fed the vast imagination about climate change to set the so-called cli-fi. The concept of the Anthropocene is the new geological era which begins when the Man actions have reached a sufficient power to modify the geological processes and climatic cycles of the planet5. The Anthropocene by no means excludes the possibility of an apocalyptic horizon, namely in the perspectives of the Great Acceleration. On the contrary, two scenarios do indeed seem to dispute the future of the Anthropocene, with a dramatic cross-charge. The stories of the end of the world are as old as it is, as the world is the origin of these stories. However, these stories of the apocalypse have evolved over time and, since the beginning of the 19th century, they have been nourished particularly by science and its advances. These fictions have sometimes tried to pass themselves off as science. This is the current vogue, called collapsology6. This end is more than likely cli-fi driven7and it may cause the extinction of the many species including the Homo Sapiens Sapiens. In this vein, Anthropocene defaunation has become an ultimate reality8. More than one in eight birds, more than one in five mammals, more than one in four coniferous species, one in three amphibians are threatened. The hypothesis of a hierarchy within the living is induced by the error of believing that evolution goes from the simplest to the most sophisticated, from the inevitably stupid inferior to the superior endowed with an intelligence giving prerogative to all powers. Evolution goes in all directions and pursues no goal except the extension of life on Earth. Evolution certainly does not lead from bacteria to humans, preferably male and white. Our species is only a carrier of the DNA that precedes us and that will survive us. Until we show a deep respect for the biosphere particularly, and our planet in general, we will not become much, we will remain a predator among other predators, the fiercest of predators, the almighty craftsman of the Anthropocene. To be in the depths of our humanity, somehow giving back to the biosphere what we have taken from it seems obvious. To stop the sixth extinction of species, we must condemn our anthropocentrism and the anthropization of the territories that goes with it. The other forms of life also need to keep their ecological niches. According to the first, humanity seems at first to withdraw from the limits of the planet and ultimately succumb to them, with a loss of dramatic meaning. According to the second, from collapse to collapse, it is perhaps another humanity, having overcome its demons, that could come. Climate fiction is a literary sub-genre dealing with the theme of climate change, including global warming. The term appears to have been first used in 2008 by blogger and writer Dan Bloom. In October 2013, Angela Evancie, in a review of the novel Odds against Tomorrow, by Nathaniel Rich, wonders if climate change has created a new literary genre. Scientific basis of the apocalyptic scenario in the perspective of the Anthropocene Global warming All temperature indices are in favour of a global warming (Fig.1). According to the different scenarios of the IPCC9, the temperatures of the globe could increase by 2 °C to 5 °C by 2100. But some scientists warn about a possible runaway of the warming which can reach more than 3 °C. Thus, the average temperature on the surface of the globe has already increased by more than 1.1 °C since the pre-industrial era. The rise in average temperatures at the surface of the globe is the first expected and observed consequence of massive greenhouse gas emissions. However, meteorological surveys record positive temperature anomalies which are confirmed from year to year compared to the temperatures recorded since the middle of the 19th century. Climatologists point out that the past 30 years have seen the highest temperatures in the Northern Hemisphere for over 1,400 years. Several climatic centres around the world record, synthesize and follow the evolution of temperatures on Earth. Since the beginning of the 20th century (1906-2005), the average temperature at the surface of the globe has increased by 0.74 °C, but this progression has not been continuous since 1976, the increase has clearly accelerated, reaching 0.19 °C per decade according to model predictions. Despite the decline in solar activity, the period 1997-2006 is marked by an average positive anomaly of 0.53 °C in the northern hemisphere and 0.27 °C in the southern hemisphere, still compared to the normal calculated for 1961-1990. The ten hottest years on record are all after 1997. Worse, 14 of the 15 hottest years are in the 21st century, which has barely started. Thus, 2016 is the hottest year, followed closely by 2015, 2014 and 2010. The temperature of tropical waters increased by 1.2 °C during the 20th century (compared to 0.5 °C on average for the oceans), causing coral reefs to bleach in 1997. In 1998, the period of Fort El Niño, the prolonged warming of the water has destroyed half of the coral reefs of the Indian Ocean. In addition, the temperature in the tropics of the five ocean basins, where cyclones form, increased by 0.5 °C from 1970 to 2004, and powerful cyclones appeared in the North Atlantic in 2005, while they were more numerous in other parts of the world. Recently, mountains of studies focused on the possible scenario of climate change and the potential worldwide repercussions including hell temperatures and apocalyptic extreme events10 , 11, 12. Melting of continental glaciers As a direct result of the global warming, melting of continental glaciers has been recently noticed13. There are approximately 198,000 mountain glaciers in the world; they cover an area of approximately 726,000 km2. If they all melted, the sea level would rise by about 40 cm. Since the late 1960s, global snow cover has declined by around 10 to 15%. Winter cold spells in much of the northern half of the northern hemisphere are two weeks shorter than 100 years ago. Glaciers of mountains have been declining all over the world by an average of 50 m per decade for 150 years. However, they are also subject to strong multi-temporal variations which make forecasts on this point difficult according to some specialists. In the Alps, glaciers have been losing 1 meter per year for 30 years. Polar glaciers like those of Spitsbergen (about a hundred km from the North Pole) have been retreating since 1880, releasing large quantities of water. The Arctic has lost about 10% of its permanent ice cover every ten years since 1980. In this region, average temperatures have increased at twice the rate of elsewhere in the world in recent decades. The melting of the Arctic Sea ice has resulted in a loss of 15% of its surface area and 40% of its thickness since 1979. The record for melting arctic sea ice was set in 2017. All models predict the disappearance of the Arctic Sea ice in summer within a few decades, which will not be without consequences for the climate in Europe. The summer melting of arctic sea ice accelerated far beyond climate model predictions. Added to its direct repercussions of coastal regions flooding, melting of continental ice leads to radical climatic modifications in favour of the apocalyptic scenario. Fig.1 Evolution of temperature anomaly from 1880 to 2020: the apocalyptic scenario Sea level rise As a direct result of the melting of continental glaciers, sea level rise has been worldwide recorded14 ,15. The average level of the oceans has risen by 22 cm since 1880 and 2 cm since the year 2000 because of the melting of the glaciers but also with the thermal expansion of the water. In the 20th century, the sea level rose by around 2 mm per year. From 1990 to 2017, it reached the relatively constant rate of just over 3mm per year. Several sources contributed to sea level increase including thermal expansion of water (42%), melting of continental glaciers (21%), melting Greenland glaciers (15%) and melting Antarctic glaciers (8%). Since 2003, there has always been a rapid rise (around 3.3 mm / year) in sea level, but the contribution of thermal expansion has decreased (0.4 mm / year) while the melting of the polar caps and continental glaciers accelerates. Since most of the world’s population is living on coastal regions, sea level rise represents a real threat for the humanity, not excluding the apocalyptic scenario. Multiplication of extreme phenomena and climatic anomalies On a human scale, an average of 200 million people is affected by natural disasters each year and approximately 70,000 perish from them. Indeed, as evidenced by the annual reviews of disasters and climatic anomalies, we are witnessing significant warning signs. It is worth noting that these observations are dependent on meteorological survey systems that exist only in a limited number of countries with statistics that rarely go back beyond a century or a century and a half. In addition, scientists are struggling to represent the climatic variations of the last two thousand years which could serve as a reference in the projections. Therefore, the exceptional nature of this information must be qualified a little. Indeed, it is still difficult to know the return periods of climatic disasters in each region. But over the last century, the climate system has gone wild. Indeed, everything suggests that the climate is racing. Indeed, extreme events and disasters have become more frequent. For instance, less than 50 significant events were recorded per year over the period 1970-1985, while there have been around 120 events recorded since 1995. Drought has long been one of the most worrying environmental issues. But while African countries have been the main affected so far, the whole world is now facing increasingly frequent and prolonged droughts. Chile, India, Australia, United States, France and even Russia are all regions of the world suffering from the acceleration of the global drought. Droughts are slowly evolving natural hazards that can last from a few months to several decades and affect larger or smaller areas, whether they are small watersheds or areas of hundreds of thousands of square kilometres. In addition to their direct effects on water resources, agriculture and ecosystems, droughts can cause fires or heat waves. They also promote the proliferation of invasive species, creating environments with multiple risks, worsening the consequences on ecosystems and societies, and increasing their vulnerability. Although these are natural phenomena, there is a growing understanding of how humans have amplified the severity and impacts of droughts, both on the environment and on people. We influence meteorological droughts through our action on climate change, and we influence hydrological droughts through our management of water circulation and water processes at the local scale, for example by diverting rivers or modifying land use. During the Anthropocene (the present period when humans exert a dominant influence on climate and environment), droughts are closely linked to human activities, cultures, and responses. From this scientific overview, it may be concluded apocalyptic scenario is not only a literature genre inspired from the pure imagination. Instead, many scientific arguments are in favour of this dramatic destiny of Homo Sapiens Sapiens. Fig.2. Sea level rise from 1880 to 2020: a possible apocalyptic scenario (www.globalchange.gov, 2021) Apocalyptic genre in recent writing As the original landmark of apocalyptic writing, we must place the destruction of the Temple of Jerusalem in 587 BC and the Exile in Babylon. Occasion of a religious and cultural crossing with imprescriptible effects, the Exile brought about a true rebirth, characterized by the maintenance of the essential ethical, even cultural, of a national religion, that of Moses, kept as pure as possible on a foreign land and by the reinterpretation of this fundamental heritage by the archaic return of what was very old, both national traditions and neighbouring cultures. More precisely, it was the place and time for the rehabilitation of cultures and the melting pot for recasting ancient myths. This vast infatuation with Antiquity, remarkable even in the vocabulary used, was not limited to Israel: it even largely reflected a general trend. The long period that preceded throughout the 7th century BC and until 587, like that prior to the edict of Cyrus in 538 BC, was that of restorations and rebirths, of returns to distant sources and cultural crossings. In the biblical literature of this period, one is struck by the almost systematic link between, on the one hand, a very sustained mythical reinvestment even in form and, on the other, the frequent use of biblical archaisms. The example of Shadday, a word firmly rooted in the Semites of the Northwest and epithet of El in the oldest layers of the books of Genesis and Exodus, is most eloquent. This term reappears precisely at the time of the Exile as a designation of the divinity of the Patriarchs and of the God of Israel; Daily, ecological catastrophes now describe the normal state of societies exposed to "risks", in the sense that Ulrich Beck gives to this term: "the risk society is a society of catastrophe. The state of emergency threatens to become a normal state there1”. Now, the "threat" has become clearer, and catastrophic "exceptions" are proliferating as quickly as species are disappearing and climate change is accelerating. The relationship that we have with this worrying reality, to say the least, is twofold: on the one hand, we know very well what is happening to us; on the other hand, we fail to draw the appropriate theoretical and political consequences. This ecological duplicity is at the heart of what has come to be called the “Anthropocene”, a term coined at the dawn of the 21st century by Eugene Stoermer (an environmentalist) and Paul Crutzen (a specialist in the chemistry of the atmosphere) in order to describe an age when humanity would have become a "major geological force" capable of disrupting the climate and changing the terrestrial landscape from top to bottom. If the term “Anthropocene” takes note of human responsibility for climate change, this responsibility is immediately attributed to overpowering: strong as we are, we have “involuntarily” changed the climate for at least two hundred and fifty years. Therefore, let us deliberately change the face of the Earth, if necessary, install a solar shield in space. Recognition and denial fuel the signifying machine of the Anthropocene. And it is precisely what structures eco-apocalyptic cinema that this article aims to study. By "eco-apocalyptic cinema", we first mean a cinematographic sub-genre: eco-apocalyptic and post-eco-apocalyptic films base the possibility (or reality) of the end of the world on environmental grounds and not, for example, on damage caused by the possible collision of planet Earth with a comet. Post-apocalyptic science fiction (sometimes abbreviated as "post-apo" or "post-nuke") is a sub-genre of science fiction that depicts life after a disaster that destroyed civilization: nuclear war, collision with a meteorite, epidemic, economic or energy crisis, pandemic, alien invasion. Conclusion Climate and politics have been linked together since Aristotle. With Montesquieu, Ibn Khaldûn or Watsuji, a certain climatic determinism is attributed to the character of a nation. The break with modernity made the climate an object of scientific knowledge which, in the twentieth century, made it possible to document, despite the controversies, the climatic changes linked to industrialization. Both endanger the survival of human beings and ecosystems. Climate ethics are therefore looking for a new relationship with the biosphere or Gaia. For some, with the absence of political agreements, it is the beginning of inevitable catastrophes. For others, the Anthropocene, which henceforth merges human history with natural history, opens onto technical action. The debate between climate determinism and human freedom is revived. The reference to the biblical Apocalypse was present in the thinking of thinkers like Günther Anders, Karl Jaspers or Hans Jonas: the era of the atomic bomb would mark an entry into the time of the end, a time marked by the unprecedented human possibility of 'total war and annihilation of mankind. The Apocalypse will be very relevant in describing the chaos to come if our societies continue their mad race described as extra-activist, productivist and consumerist. In dialogue with different theologians and philosophers (such as Jacques Ellul), it is possible to unveil some spiritual, ethical, and political resources that the Apocalypse offers for thinking about History and human engagement in the Anthropocene. What can a theology of collapse mean at a time when negative signs and dead ends in the human situation multiply? What then is the place of man and of the cosmos in the Apocalypse according to Saint John? Could the end of history be a collapse? How can we live in the time we have left before the disaster? Answers to such questions remain unknown and no scientist can predict the trajectory of this Great Acceleration taking place at the Late Anthropocene. When science cannot give answers, Man tries to infer his destiny for the legend, religion and the fiction. Climate Fiction is developed into a recording machine containing every kind of fictions that depict environmental condition events and has consequently lost its true significance. Aware of the prospect of ecological collapse additionally as our apparent inability to avert it, we tend to face geology changes of forceful proportions that severely challenge our ability to imagine the implications. Climate fiction ought to be considered an important supplement to climate science, as a result, climate fiction makes visible and conceivable future modes of existence inside worlds not solely deemed seemingly by science, however that area unit scientifically anticipated. Hence, this chapter, as part of the book itself, aims to contribute to studies of ecocriticism, the environmental humanities, and literary and culture studies. References David P.G. Bondand Stephen E. Grasby. "Late Ordovician mass extinction caused by volcanism, warming, and anoxia, not cooling and glaciation: REPLY." Geology 48, no. 8 (Geological Society of America2020): 510. Cyril Langlois.’Vestiges de l'apocalypse: ‘le site de Tanis, Dakota du Nord 2019’. Accessed June, 6, 2021, https://planet-terre.ens-lyon.fr/pdf/Tanis-extinction-K-Pg.pdf NajouaGharsalli,ElhoucineEssefi, Rana Baydoun, and ChokriYaich. ‘The Anthropocene and Great Acceleration as controversial epoch of human-induced activities: case study of the Halk El Menjel wetland, eastern Tunisia’. Applied Ecology and Environmental Research 18(3) (Corvinus University of Budapest 2020): 4137-4166 Elhoucine Essefi, ‘On the Geochemistry and Mineralogy of the Anthropocene’. International Journal of Water and Wastewater Treatment, 6(2). 1-14, (Sci Forschen2020): doi.org/10.16966/2381-5299.168 Elhoucine Essefi. ‘Record of the Anthropocene-Great Acceleration along a core from the coast of Sfax, southeastern Tunisia’. Turkish journal of earth science, (TÜBİTAK,2021). 1-16. Chiara Xausa. ‘Climate Fiction and the Crisis of Imagination: Alexis Wright’s Carpentaria and The Swan Book’. Exchanges: The Interdisciplinary Research Journal 8(2), (WARWICK 2021): 99-119. Akyol, Özlem. "Climate Change: An Apocalypse for Urban Space? An Ecocritical Reading of “Venice Drowned” and “The Tamarisk Hunter”." Folklor/Edebiyat 26, no. 101 (UluslararasıKıbrısÜniversitesi 2020): 115-126. Boswell, Suzanne F. "The Four Tourists of the Apocalypse: Figures of the Anthropocene in Caribbean Climate Fiction.". Paradoxa 31, (Academia 2020): 359-378. Ayt Ougougdal, Houssam, Mohamed YacoubiKhebiza, Mohammed Messouli, and Asia Lachir. "Assessment of future water demand and supply under IPCC climate change and socio-economic scenarios, using a combination of models in Ourika Watershed, High Atlas, Morocco." Water 12, no. 6 (MPDI 2020): 1751.DOI:10.3390/w12061751. Wu, Jia, Zhenyu Han, Ying Xu, Botao Zhou, and Xuejie Gao. "Changes in extreme climate events in China under 1.5 C–4 C global warming targets: Projections using an ensemble of regional climate model simulations." Journal of Geophysical Research: Atmospheres 125, no. 2 (Wiley2020): e2019JD031057.https://doi.org/10.1029/2019JD031057 Khan, Md Jamal Uddin, A. K. M. Islam, Sujit Kumar Bala, and G. M. Islam. "Changes in climateextremes over Bangladesh at 1.5° C, 2° C, and 4° C of global warmingwith high-resolutionregionalclimate modeling." Theoretical&AppliedClimatology 140 (EBSCO2020). Gudoshava, Masilin, Herbert O. Misiani, Zewdu T. Segele, Suman Jain, Jully O. Ouma, George Otieno, Richard Anyah et al. "Projected effects of 1.5 C and 2 C global warming levels on the intra-seasonal rainfall characteristics over the Greater Horn of Africa." Environmental Research Letters 15, no. 3 (IOPscience2020): 34-37. Wang, Lawrence K., Mu-Hao Sung Wang, Nai-Yi Wang, and Josephine O. Wong. "Effect of Global Warming and Climate Change on Glaciers and Salmons." In Integrated Natural Resources Management, ed.Lawrence K. Wang, Mu-Hao Sung Wang, Yung-Tse Hung, Nazih K. Shammas(Springer 2021), 1-36. Merschroth, Simon, Alessio Miatto, Steffi Weyand, Hiroki Tanikawa, and Liselotte Schebek. "Lost Material Stock in Buildings due to Sea Level Rise from Global Warming: The Case of Fiji Islands." Sustainability 12, no. 3 (MDPI 2020): 834.doi:10.3390/su12030834 Hofer, Stefan, Charlotte Lang, Charles Amory, Christoph Kittel, Alison Delhasse, Andrew Tedstone, and Xavier Fettweis. "Greater Greenland Ice Sheet contribution to global sea level rise in CMIP6." 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Clements Markham Inlet cuts into the Grant Land Mountains of the northernmost coast of Ellesmere Island. The head of the inlet is bounded on three sides by mountain ice caps that surround lowlands mantled by extensive raised marine deposits. Fieldwork and mapping of late Quaternary sediments were used to determine the limits of past glaciations and the nature of ice retreat from the inlet head. Forty-five radiocarbon dates on driftwood and marine shells provide a deglacial chronology and document related sea-level adjustments.High-level ice-marginal meltwater channels and mountain summit erratics indicate that ice once inundated all of Clements Markham Inlet. During at least one of these undated glaciations, ice flowed unconstrained by the local topography. In contrast, the most recent glaciation involved confluent trunk glaciers, which terminated near the head of the inlet. Beyond this terminus, smaller glaciers entering the sides of the inlet debouched into a glacioisostatically depressed sea (full glacial sea). Retreat from the last glaciation is documented by moraines, kame terraces, and ice-contact deltas.Inside the ice limit at the head of the inlet, sections commonly show that a marine transgression occurred immediately after the retreat of the ice. Conversely, sections outside the last ice limit, along the sides of the inlet, show complex intercalations of marine and glacigenic sediments. These indicate proximal ice-front conditions where small valley glaciers locally contacted the sea.The oldest date on the last ice limit is 9845 BP. After this, slow retreat was in progress, and some glaciers were within 6 km of their current positions by ca. 9700 BP. At the head of the inlet, the mouths of the confluent valleys became ice free by 8000 BP. After 8000 BP, glacial retreat accelerated greatly, so that the entire lowland became ice free within 400 years.Relative sea-level curves from the inlet indicate ice-load changes that confirm this pattern of ice retreat. Outside the last ice limit, the full glacial sea reached 124 m asl by at least 10 000 BP. Emergence from this sea occurred slowly between at least 10 000 and 8000 BP (0.72 m 100 year−1). This period was followed by "normal" rapid postglacial emergence, which decelerated to the present.The marine limit of the full glacial sea rises from 92 m asl, at the outer coast, to 124 m asl near the last ice limit at the head of the inlet. Initial emergence from the full glacial sea occurred simultaneously throughout the inlet. On the proximal side of the last ice limit, the marine limit descends in the up-ice direction and becomes progressively younger. Individual strandlines tilt up in a southwesterly direction towards the central Grant Land Mountains, suggesting a former centre of glacio-isostatic loading in that area.

AbstractTime-dependent ice-sheet modelling of a 176 000 km2 area in western Dronning Maud Land, East Antarctica, provided information on the ice sheet’s response to six climate-change scenarios. Another experiment was done to study changes in ice thickness, flow and basal temperature conditions between the present ice configuration and a simulated maximum palaeo-ice sheet. The input to the model included new datasets of bed and surface topography compiled for this study. The results of the six climate-change experiments, including a 0.5°C per century global-warming scenario, show that the ice sheet has a robust behaviour with respect to the different climate changes. The maximum change in ice volume was <5% of the initial volume in all climate runs. This is for only relatively short-term climate changes without major changes in global sea level, and also a simulated ice sheet without an ice shelf. The modelled long-term response time of the ice sheet, 20 kyr or more, indicates that the ice sheet may still be adjusting to the climate change that ended the Last Glacial Maximum. In the maximum palaeo-ice-sheet simulation, with a 5°C climate cooling and the grounding line located at the continental-shelf margin, ice thickness increased drastically downstream from the Heimefrontfjella mountain range but remained basically unaffected on the upstream polar plateau. Compared to present conditions, complex changes in basal temperatures were observed. The extent of areas with basal melting increased, for example in the deep trough of the Veststraumen ice stream. Areas at intermediate elevations in the landscape also experienced increased basal temperatures, with significant areas reaching the melting point. In contrast, high-altitude areas that today are clearly cold-based, such as around Heimefrontfjella and Vestfjella and the Högisen dome, experienced a 5–10°C decrease in basal temperatures in the palaeo-ice-sheet reconstruction. The results suggest that the alpine landscape within these mountain regions was formed by wet-based local glaciers and ice sheets prior to the late Cenozoic.

Abstract The East African climate paradox—a term framing the observed precipitation decline in the March–May (MAM) wet season of East Africa from roughly 1980–2010, yet an increase in future climates simulated by global climate models (GCMs)—mostly relies on data representing sea level. Here we add a mid-troposphere perspective by combining in-situ meteorological measurements at ∼6000 m a.s.l. from Africa’s highest mountain summit and a carefully selected subset of GCMs through a machine-learning link. Temporal trends of the resultant six weather types do support a drier mountain climate in the recent past and a moister one in the course of the 21st century, and a key to understanding these contrasting trends materializes from the new dominance of changes in weather type frequency in the future climate. Importantly, however, the results also suggest that the trend reversal requires a strong external climate forcing. Hence, the forcing strength should be considered more systematically in forthcoming studies, to challenge the question whether equatorial East Africa’s MAM climate will indeed become wetter in all plausible future scenarios.

Following international recommendations (UNESCO / IASH 1969), the decision was made to determine the surface profile of a number of glaciers in Palmer Land and Alexander Island. By comparison with the ice sheet elsewhere on the continent, the chosen glaciers were small and hence more sensitive to the effect of climate over the last few decades. Six profiles were established between 1972 and 1976 and they were re-levelled in the 1985-86 summer. The profiles are between 0.5 and 4.5 km long and are terminated, at one end at least, by a bench mark established on rock. The profiles were re-measured close to the calendar date of the original survey so that recent trends would not be masked by the annual cycle of accumulation, densification and ablation. Five of the six profiles show that the ice sheet has thickened in the last 10-15 years, albeit at a slow rate. Changes in four profiles on Alexander Island within 300 m of sea-level range from a thickening of 66 mm a−1 to a thinning of 83 mm a−1; on average the sites show a thickening of just 6 mm a year. This is similar to the thickening rate of 5 mm a−1 which was found for a cold site on the spine of the Antarctic Peninsula at 1600 m above sea-level. The greatest change was found at an intermediate elevation (500 m). In a snow-field between two parallel mountain groups in the Batterbee Mountains of Palmer Land, thickening averaged 165 mm a−1. To put these values into perspective, in the absence of glacier flow and summer melting, the glaciers would thicken by up to about 500 mm each year as a result of the accumulation of snow.Except in the Batterbee Mountains, we find that glacier flow is in close balance with present climate, despite the general warming trend that has occurred in the Antarctic Peninsula region over the past 30 years.

Following international recommendations (UNESCO / IASH 1969), the decision was made to determine the surface profile of a number of glaciers in Palmer Land and Alexander Island. By comparison with the ice sheet elsewhere on the continent, the chosen glaciers were small and hence more sensitive to the effect of climate over the last few decades. Six profiles were established between 1972 and 1976 and they were re-levelled in the 1985-86 summer. The profiles are between 0.5 and 4.5 km long and are terminated, at one end at least, by a bench mark established on rock. The profiles were re-measured close to the calendar date of the original survey so that recent trends would not be masked by the annual cycle of accumulation, densification and ablation. Five of the six profiles show that the ice sheet has thickened in the last 10-15 years, albeit at a slow rate. Changes in four profiles on Alexander Island within 300 m of sea-level range from a thickening of 66 mm a−1 to a thinning of 83 mm a−1; on average the sites show a thickening of just 6 mm a year. This is similar to the thickening rate of 5 mm a−1 which was found for a cold site on the spine of the Antarctic Peninsula at 1600 m above sea-level. The greatest change was found at an intermediate elevation (500 m). In a snow-field between two parallel mountain groups in the Batterbee Mountains of Palmer Land, thickening averaged 165 mm a−1. To put these values into perspective, in the absence of glacier flow and summer melting, the glaciers would thicken by up to about 500 mm each year as a result of the accumulation of snow. Except in the Batterbee Mountains, we find that glacier flow is in close balance with present climate, despite the general warming trend that has occurred in the Antarctic Peninsula region over the past 30 years.

Abstract. Glacier inventories provide essential baseline information for the determination of water resources, glacier-specific changes in area and volume, climate change impacts as well as past, potential and future contribution of glaciers to sea-level rise. Although Greenland is heavily glacierised and thus highly relevant for all of the above points, a complete inventory of its glaciers was not available so far. Here we present the results and details of a new and complete inventory that has been compiled from more than 70 Landsat scenes (mostly acquired between 1999 and 2002) using semi-automated glacier mapping techniques. A digital elevation model (DEM) was used to derive drainage divides from watershed analysis and topographic attributes for each glacier entity. To serve the needs of different user communities, we assigned to each glacier one of three connectivity levels with the ice sheet (CL0, CL1, CL2; i.e. no, weak, and strong connection) to clearly, but still flexibly, distinguish the local glaciers and ice caps (GIC) from the ice sheet and its outlet glaciers. In total, we mapped ~ 20 300 glaciers larger than 0.05 km2 (of which ~ 900 are marine terminating), covering an area of 130 076 ± 4032 km2, or 89 720 ± 2781 km2 without the CL2 GIC. The latter value is about 50% higher than the mean value of more recent previous estimates. Glaciers smaller than 0.5 km2 contribute only 1.5% to the total area but more than 50% (11 000) to the total number. In contrast, the 25 largest GIC (> 500 km2) contribute 28% to the total area, but only 0.1% to the total number. The mean elevation of the GIC is 1700 m in the eastern sector and around 1000 m otherwise. The median elevation increases with distance from the coast, but has only a weak dependence on mean glacier aspect.

The freezing level in the free troposphere often intercepts the terrain of the world’s major mountain ranges, creating a rain–snow limit. In this work, we use the free tropospheric height of the 0 °C isotherm (H0) as a proxy of both levels and study its distribution along the western slope of the subtropical Andes (30°–38° S) in present climate and during the rest of the 21st century. This portion of the Andes corresponds to central Chile, a highly populated region where warm winter storms have produced devastating landslides and widespread flooding in the recent past. Our analysis is based on the frequency distribution of H0 derived from radiosonde and surface observations, atmospheric reanalysis and climate simulations. The future projections primarily employ a scenario of heavy greenhouse gasses emissions (RCP8.5), but we also examine the more benign RCP4.5 scenario. The current H0 distribution along the central Chile coast shows a gradual decrease southward, with mean heights close to 2600 m ASL (above sea level) at 30 °C S to 2000 m ASL at 38° S for days with precipitation, about 800 m lower than during dry days. The mean value under wet conditions toward the end of the century (under RCP8.5) is close to, or higher than, the upper quartile of the H0 distribution in the current climate. More worrisome, H0 values that currently occur only 5% of the time will be exceeded in about a quarter of the rainy days by the end of the century. Under RCP8.5, even moderate daily precipitation can increase river flow to levels that are considered hazardous for central Chile.

Observations of sea-level changes in the 20th century show a rise of 1 to 2 mm year−1, with accelerating rates in recent decades (IPCC, 2001, 2007b). Contributions to these changes include thermal expansion, recent melting of ice masses (Antarctica, Greenland, and mountain glaciers), and changes in terrestrial water storage. To quantify the contribution from recent mountain deglaciation, a global numerical model based on climate parameters is developed, incorporating seasonal variations in ice volume of 100 glaciated regions. The estimated melt-water from mountain glaciers contributed between 0.25 and 0.43 mm year−1 to global sea-level rise over the period 1961-1990, and between 0.47 and 0.58 mm year−1 over 1991-2000. This is consistent with directly observed ice-volume changes. Thus, confident predictions for future changes can be made using the same numerical model. It is predicted that mountain glaciers will contribute ~1.5 mm year−1 on average over the remainder of this century. As well as the volumetric effect of the melt-water, local sea level is affected by the deflection of the crust and geoid in response to the change in surface load. Relative sea-level is predicted to rise on most of the worlds coastlines, but at sites located close to the melting glaciers sea-level is predicted to fall at a rate that reaches several times the average value, and estimates of geodetic signals are therefore strongly dependent on the region under investigation. The distinctive geographical pattern of the changes due to mountain deglaciation is dependent on a number of other factors which have also been addressed in this study. These include both the total and regional ice-volume loss of glaciers, the spatial representation of the glaciated areas, and the Earth models used. As the predicted geodetic signals at sites located close to large-scale glacier systems are of a magnitude that can be observed with geodetic techniques, these methods can provide additional constraints on the ice-volume loss of mountain glaciers.