Samuel U. Nussbaumer

Historical glacier fluctuations of Jostedalsbreen and Folgefonna (southern Norway) reassessed by new pictorial and written evidence

Glaciers are sensitive indicators of past climate and thus valuable sources of climate history. Unfortunately, direct determinations of glacier changes (variations in length and mass balance) did not start with increasing accuracy before the end of the nineteenth century. Therefore, historical and geomorphological evidence has to be used to reconstruct glacier variability for preceding time periods. Here we present new glacier length reconstructions for selected outlet glaciers of Jostedalsbreen and Folgefonna (two ice caps in southern Norway). A wealth of different historical sources (drawings, paintings, prints, photographs, maps, written accounts; about 400 documents) allows reconstruction of glacier length variations for the last 300 (Jostedalsbreen), and 200 years (Folgefonna), respectively. We present historical material newly collected for Briksdalsbreen, Bøyabreen, Store Supphellebreen, Bergsetbreen, Nigardsbreen, Lodalsbreen (all Jostedalsbreen), and Bondhusbrea, Buerbreen (both southern Folgefonna). At Jostedalsbreen, glaciers reached their ‘Little Ice Age’ (LIA) maximum extent around AD 1750. Nigardsbreen is best documented, where also the advance in the mid-eighteenth century can be quantified. However, the nearby Bergsetbreen shows more distinct glacier advances and retreats since the LIA maximum extent. A minor peak is documented in the 1870s for all outlet glaciers of Jostedalsbreen studied. At southern Folgefonna, the LIA maximum was attained in the late 1870s (second peak around 1890). So far, there is no direct historical evidence for the time before AD 1800.

Climate and glacier fluctuations at Jostedalsbreen and Folgefonna, southwestern Norway and in the western Alps from the 'Little Ice Age' until the present: The influence of the North Atlantic Oscillation

Glacier length, though an indirect and delayed signal of climate conditions, can be used to determine the relationship between climate and glacier response. This study discusses glacier length change of eight outlet glaciers of Jostedalsbreen and Folgefonna (southern Norway), from the ‘Little Ice Age’ (LIA) until the present. A climate index was calculated from meteorological data from Bergen to determine the specific frontal time lags of the individual glaciers. Short and steep outlet glaciers, such as Briksdalsbreen, react rapidly to changes in climatic conditions, whereas long and gently descending glaciers, such as Nigardsbreen, need longer time to adjust to changes in temperature and/or precipitation. The time lag of Briksdalsbreen was about twice as long during the LIA as today. The correlations between North Atlantic Oscillation (NAO) and climate conditions and glacier fluctuations in Norway and the European western Alps were analysed. As the influence of the NAO on glacier fluctuations is most pronounced during winter, only the winter NAO index was considered. Fluctuations of maritime Norwegian glaciers are highly correlated with the NAO, whereas variations of more continental glaciers in the European western Alps are only partly influenced by the NAO and tend to be anti-correlated. However, the (anti-)correlation with the NAO is not constant during the record, and significantly weaker or even inversed during some periods. A comparison of the LIA glacier fluctuations in southern Norway and the European western Alps suggests that the asynchronous LIA maxima in the two regions may partly be attributed to multidecadal trends in the NAO.

Perennial snow and ice variations (2000–2008) in the Arctic circumpolar land area from satellite observations

Perennial snow and ice (PSI) extent is an important parameter of mountain environments with regard to its involvement in the hydrological cycle and the surface energy budget. We investigated interannual variations of PSI in nine mountain regions of interest (ROI) between 2000 and 2008. For that purpose, a novel MODIS data set processed at the Canada Centre for Remote Sensing at 250 m spatial resolution was utilized. The extent of PSI exhibited significant interannual variations, with coefficients of variation ranging from 5% to 81% depending on the ROI. A strong negative relationship was found between PSI and positive degree-days (threshold 0°C) during the summer months in most ROIs, with linear correlation coefficients (r) being as low as r = −0.90. In the European Alps and Scandinavia, PSI extent was significantly correlated with annual net glacier mass balances, with r = 0.91 and r = 0.85, respectively, suggesting that MODIS-derived PSI extent may be used as an indicator of net glacier mass balances. Validation of PSI extent in two land surface classifications for the years 2000 and 2005, GLC-2000 and Globcover, revealed significant discrepancies of up to 129% for both classifications. With regard to the importance of such classifications for land surface parameterizations in climate and land surface process models, this is a potential source of error to be investigated in future studies. The results presented here provide an interesting insight into variations of PSI in several ROIs and are instrumental for our understanding of sensitive mountain regions in the context of global climate change assessment.

Climate Change Adaptation Strategies – An Upstream-downstream Perspective

Climate change and the related adverse impacts are among the greatest challenges facing humankind during the coming decades. Even with a significant reduction of anthropogenic greenhouse gas emissions, it will be inevitable for societies to adapt to new climatic conditions and associated impacts and risks. This book offers insights to first experiences of developing and implementing adaptation measures, with a particular focus on mountain environments and the adjacent downstream areas. It provides a comprehensive ‘state-of-the-art’ of climate change adaptation in these areas through the collection and evaluation of knowledge from several local and regional case studies and by offering new expertise and insights at the global level. As such, the book is an important source for scientists, practitioners and decision makers alike, who are working in the field of climate change adaptation and towards sustainable development in the sense of the Paris Agreement and the Agenda 2030.

Glacier inventory and recent glacier variations in the Andes of Chile, South America

ABSTRACT The first satellite-derived inventory of glaciers and rock glaciers in Chile, created from Landsat TM/ETM+ images spanning between 2000 and 2003 using a semi-automated procedure, is presented in a single standardized format. Large glacierized areas in the Altiplano, Palena Province and the periphery of the Patagonian icefields are inventoried. The Chilean glacierized area is 23 708 ± 1185 km2, including ~3200 km2 of both debris-covered glaciers and rock glaciers. Glacier distribution varies as a result of climatic gradients with latitude and elevation, with 0.8% occurring in the Desert Andes (17°30′–32° S); 3.6% in the Central Andes (32–36° S), 6.2% in the Lakes District and Palena Province (36–46° S), and 89.3% in Patagonia and Tierra del Fuego (46–56° S). Glacier outlines, across all glacierized regions and size classes, updated to 2015 using Landsat 8 images for 98 complexes indicate a decline in areal extent affecting mostly clean-ice glaciers (−92.3 ± 4.6 km2), whereas debris-covered glaciers and rock glaciers in the Desert and Central Andes appear nearly unchanged in their extent. Glacier attributes estimated from this new inventory provide valuable insights into spatial patterns of glacier shrinkage for assessing future glacier changes in response to climate change.

Analysis of Weather- and Climate-Related Disasters in Mountain Regions Using Different Disaster Databases

Mountains are fragile ecosystems with global importance, providing key ecosystems services within mountainous areas but also for the lowlands. However, mountain regions are prone to natural disasters and exposed to multiple hazards. In this chapter, we present four disaster databases (EM-DAT, NatCatSERVICE, DesInventar, Dartmouth) that store information about spatiotemporal occurrence and impacts of natural disasters in mountain areas. Quality and completeness of the four databases are compared and analyzed regarding reliability for weather- and climate-related natural disasters. The analysis identifies the numbers of fatalities as the most reliable loss parameters, whereby the number of people affected and the economic loss are less trustworthy and highly dependent on the purposes of each database. Main limitations regarding sustainable mountain development are the inhomogeneity in database definitions, spatial resolutions, database purposes and lack of data registration for human and economic losses. While some individual disasters such as the Kedarnath flood in northern India in 2013 have been robustly linked to changes in climate, there is generally insufficient evidence to attribute any overall increasing disaster frequency to climate change. Damage due to hazard in mountain regions will increase irrespective of global warming, in regions where populations are growing and infrastructure is developed at exposed locations.

Evidence from the Archives of Societies: Historical Sources in Glaciology

Glaciers have been recognized as key indicators of climate change. To assess the current decline in glaciers worldwide, their changes must be compared with natural glacier fluctuations since the end of the last ice age. To reconstruct glacier changes over recent centuries, historical methods have proven especially valuable. Pictorial and cartographical documents as well as written accounts can provide a detailed picture of glacier fluctuations, in particular frontal length changes.

Elevation changes of the Holm Land Ice Cap, northeast Greenland, from 1978 to 2012–2015, derived from high-resolution digital elevation models

ABSTRACT Greenland’s peripheral glaciers and ice caps are key indicators of climate change in the Arctic, but quantitative observational data of their recent evolution are sparse. Three recently released high-resolution digital elevation models (DEMs)—AeroDEM (based on images from 1978 to 1987), ArcticDEM (2012–2015), and TanDEM-X (2010–2014)—provide the possibility to calculate elevation changes spanning almost four decades along the margins of the Greenland Ice Sheet. This study explores the potential of these DEMs by calculating elevation changes for the Holm Land Ice Cap (865 km2), northeast Greenland. Co-registration indicated no significant shifts between the DEMs but we encountered localized vertical offsets in AeroDEM. The data quality of ArcticDEM and TanDEM-X is high, but AeroDEM suffers from 19 percent low-quality data, which were treated as data voids. Applying two approaches to fill the data voids in the difference grid between ArcticDEM and AeroDEM, mean surface-elevation change over the Holm Land Ice Cap and a period of approximately 35 y is in the range of −8.30 ±0.30 m. Comparing ArcticDEM and TanDEM-X reveals a glacier elevation difference of 2.54 m, which may be partly related to the different retrieval techniques (optical and SAR). Overall, the DEMs have good potential for large-scale and long-term assessment of geodetic glacier mass balance.

Glacier Monitoring and Capacity Building: Important Ingredients for Sustainable Mountain Development

Glacier observation data from major mountain regions of the world are key to improving our understanding of glacier changes: they deliver fundamental baseline information for climatological, hydrological, and hazard assessments. In many mountain ecosystems, as well as in the adjacent lowlands, glaciers play a crucial role in freshwater provision and regulation. This article first presents the state of the art on glacier monitoring and related strategies within the framework of the Global Terrestrial Network for Glaciers (GTN-G). Both in situ measurements of changes in glacier mass, volume, and length as well as remotely sensed data on glacier extents and changes over entire mountain ranges provide clear indications of climate change. Based on experiences from capacity-building activities undertaken in the Tropical Andes and Central Asia over the past years, we also review the state of the art on institutional capacity in these regions and make further recommendations for sustainable mountain development. The examples from Peru, Ecuador, Colombia, and Kyrgyzstan demonstrate that a sound understanding of measurement techniques and of the purpose of measurements is necessary for successful glacier monitoring. In addition, establishing durable institutions, capacity-building programs, and related funding is necessary to ensure that glacier monitoring is sustainable and maintained in the long term. Therefore, strengthening regional cooperation, collaborating with local scientists and institutions, and enhancing knowledge sharing and dialogue are envisaged within the GTN-G. Finally, glacier monitoring enhances the resilience of the populations that depend on water resources from glacierized mountains or that are affected by hazards related to glacier changes. We therefore suggest that glacier monitoring be included in the development of sustainable adaptation strategies in regions with glaciated mountains.

Setting the Scene: Adapting to Climate Change – A Large-Scale Challenge with Local-Scale Impacts

This chapter’s main objective is to provide the context of the book and to introduce the subsequent chapters.