Changes in climate extremes and their impacts on the natural physical environment: An overview of the IPCC SREX report

Himalayan glaciers are a focus of public and scientific debate. Prevailing uncertainties are of major concern because some projections of their future have serious implications for water resources. Most Himalayan glaciers are losing mass at rates similar to glaciers elsewhere, except for emerging indications of stability or mass gain in the Karakoram. A poor understanding of the processes affecting them, combined with the diversity of climatic conditions and the extremes of topographical relief within the region, makes projections speculative. Nevertheless, it is unlikely that dramatic changes in total runoff will occur soon, although continuing shrinkage outside the Karakoram will increase the seasonality of runoff, affect irrigation and hydropower, and alter hazards.

https://www.zora.uzh.ch/id/eprint/72075/1/2012_BolchT_BolchAl12_science_GlacHimal_supplm_subm_Kopie_.pdf

The state and fate of Himalayan glaciers

[1] There is increasing evidence that the amount of solar radiation incident at the Earth's surface is not stable over the years but undergoes significant decadal variations. Here I review the evidence for these changes, their magnitude, their possible causes, their representation in climate models, and their potential implications for climate change. The various studies analyzing long-term records of surface radiation measurements suggest a widespread decrease in surface solar radiation between the 1950s and 1980s (“global dimming”), with a partial recovery more recently at many locations (“brightening”). There are also some indications for an “early brightening” in the first part of the 20th century. These variations are in line with independent long-term observations of sunshine duration, diurnal temperature range, pan evaporation, and, more recently, satellite-derived estimates, which add credibility to the existence of these changes and their larger-scale significance. Current climate models, in general, tend to simulate these decadal variations to a much lesser degree. The origins of these variations are internal to the Earth's atmosphere and not externally forced by the Sun. Variations are not only found under cloudy but also under cloud-free atmospheres, indicative of an anthropogenic contribution through changes in aerosol emissions governed by economic developments and air pollution regulations. The relative importance of aerosols, clouds, and aerosol-cloud interactions may differ depending on region and pollution level. Highlighted are further potential implications of dimming and brightening for climate change, which may affect global warming, the components and intensity of the hydrological cycle, the carbon cycle, and the cryosphere among other climate elements.

/pdf/global-dimming-and-brightening-a-review-5gouad9xwm.pdf

Global dimming and brightening: A review

Structure and origin of Holocene cold events

Natural disturbances such as lava flows, landslides and glacial moraines, and human-damaged sites such as pavement, road edges and mine wastes often leave little or no soil or biological legacy. This 2003 book provided the first comprehensive summary of how plant, animal and microbial communities develop under the harsh conditions following such dramatic disturbances. The authors examine the basic principles that determine ecosystem development and apply the general rules to the urgent practical need for promoting the reclamation of damaged lands. Written for ecologists concerned with disturbance, landscape dynamics, restoration, life histories, invasions, modeling, soil formation and community or population dynamics, this book will also serve as an authoritative text for graduate students and a valuable reference for professionals involved in land management.

/pdf/primary-succession-and-ecosystem-rehabilitation-46xfnlnrj7.pdf

Primary Succession and Ecosystem Rehabilitation

Analyses of multispectral satellite data indicate accelerated glacier decline around the globe since the 1980s. By using digitized glacier outlines inferred from the 1973 inventory and Landsat Thematic Mapper (TM) satellite data from 1985 to 1999, we obtained area changes of about 930 Alpine glaciers. The 18% area reduction as observed for the period 1985 to 1999 (−1.3% a⁻¹) corresponds to a seven times higher loss rate compared to the 1850–1973 decadal mean. Extrapolation of area change rates and cumulative mass balances to all Alpine glaciers yields a corresponding volume loss of about 25 km³ since 1973. Highly individual and non-uniform changes in glacier geometry (disintegration) indicate a massive down-wasting rather than a dynamic response to a changed climate. Our results imply stronger ongoing glacier retreat than assumed so far and a probable further enhancement of glacier disintegration by positive feedbacks.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2004GL020816

Rapid disintegration of Alpine glaciers observed with satellite data

A new Swiss glacier inventory is to be compiled from satellite data for the year 2000. The study presented here describes two major tasks: (1) an accuracy assessment of different methods for glacier classification with Landsat Thematic Mapper (TM) data and a digital elevation model (DEM); (2) the geographical information system (GIS)-based methods for automatic extraction of individual glaciers from classified satellite data and the computation of three-dimensional glacier parameters (such as minimum, maximum and median elevation or slope and orientation) by fusion with a DEM. First results obtained by these methods are presented in Part II of this paper (Kaab and others, 2002). Thresholding of a ratio image from TM4 and TM5 reveals the best-suited glacier map. The computation of glacier parameters in a GIS environment is efficient and suitable for worldwide application. The methods developed contribute to the U.S. Geological Survey-led Global Land Ice Measurements from Space (GLIMS) project which is currently compiling a global inventory of land ice masses within the framework of global glacier monitoring (Haeberli and others, 2000).

/pdf/the-new-remote-sensing-derived-swiss-glacier-inventory-i-22gsnry61b.pdf

The new remote-sensing-derived Swiss glacier inventory: I. Methods

https://www.uibk.ac.at/geographie/personal/kerschner/larstig-qsr.pdf

Latest Pleistocene and Holocene glacier variations in the European Alps

Chronological data for glacier advances in the European Alps between the Last Interglacial (Eemian) and the Holocene are summarised (115 to 11 ka). During this time glaciers were most extensive, extending tens of kilometres out onto the forelands, between 30 and 18 ka, that is, synchronous with the global ice volume maximum of Marine Isotope Stage (MIS) 2. Evidence for ice expanding to just past the mountain front for an earlier major glacier advance comes from Swiss sites, where advances have been luminescence dated to MIS 5d (100 ka) and MIS 4 (70 ka). Up to now no such evidence has been found in the Eastern Alps. By 18 ka, more than 80% of the Late Wurmian ice volume had gone. Subsequently glaciers readvanced, reaching into the upper reaches of the main valleys during the Lateglacial Gschnitz stadial, which likely occurred around 17 ka, with final moraine stabilisation no later than 15.4 ka. The link of the Egesen stadial with the Younger Dryas climate deterioration is supported by exposure ages from four sites as well as minimum-limiting radiocarbon dates from bogs within former glacier tongue areas. Key questions on the spatial and temporal variability of ice extents throughout the last glacial cycle have yet to be answered. Copyright # 2008 John Wiley & Sons, Ltd.

https://uibk.ac.at/geographie/personal/kerschner/ivyjqs2008.pdf

Chronology of the last glacial cycle in the

Chronological data for glacier advances in the European Alps between the Last Interglacial (Eemian) and the Holocene are summarised (115 to 11 ka). During this time glaciers were most extensive, extending tens of kilometres out onto the forelands, between 30 and 18 ka, that is, synchronous with the global ice volume maximum of Marine Isotope Stage (MIS) 2. Evidence for ice expanding to just past the mountain front for an earlier major glacier advance comes from Swiss sites, where advances have been luminescence dated to MIS 5d (100 ka) and MIS 4 (70 ka). Up to now no such evidence has been found in the Eastern Alps. By 18 ka, more than 80% of the Late Wurmian ice volume had gone. Subsequently glaciers readvanced, reaching into the upper reaches of the main valleys during the Lateglacial Gschnitz stadial, which likely occurred around 17 ka, with final moraine stabilisation no later than 15.4 ka. The link of the Egesen stadial with the Younger Dryas climate deterioration is supported by exposure ages from four sites as well as minimum-limiting radiocarbon dates from bogs within former glacier tongue areas. Key questions on the spatial and temporal variability of ice extents throughout the last glacial cycle have yet to be answered. Copyright © 2008 John Wiley & Sons, Ltd.

https://www.uibk.ac.at/geographie/personal/kerschner/ivyjqs2008.pdf

Max Maisch

Papers

Rapid disintegration of Alpine glaciers observed with satellite data

The new remote-sensing-derived Swiss glacier inventory: I. Methods

Latest Pleistocene and Holocene glacier variations in the European Alps

Chronology of the last glacial cycle in the

Chronology of the last glacial cycle in the European Alps