Rapid Glacier Retreat Research Articles

Climate Change Impacts and Adaptation in the Nepalese Himalayas

The ongoing climatic changes and changes those are projected to occur in the near future are likely to have impacts on different sectors of Nepal. Impacts on water resources are likely to be more severe. Water resource sector ranks significantly higher than other sector because this sector is directly related to rising temperatures resulting in change in cryosphere; faster glacier melts and formation and expansion of glacial lakes and increased risk of Glacial Lake Outburst Flood (GLOF) events. The longest instrumental records of maximum temperature of Kathmandu showed that air temperature was increasing rapidly in the recent past. The records from Kathmandu showed an increase in air temperature of 0.27 oC between 1897 and 1977 and of nearly 1 oC between 1975 and 1994. Such increase in air temperature is more rapid in the higher Himalayan regions inducing more melting of snow and glacier ice. The retreat rate of terminus of Glacier AX010 in the Shorong Himal was 2.7 m a-1 from 1978 to 1989 and 16.7 m a-1 from 1989 to 2004. The ongoing rapid retreat of glaciers is leading to formation of new glacial lakes and expansion of existing glacial lakes with increasing risk of GLOF events. The area of Tsho Rolpa Glacial Lake in Dolakha district was expanded to 1.452 km2 in August 2009 from 0.23 km2 in 1959. The expanding glacial lake is holding huge amount of water within the moraine dam among which considerable amount of water may be released suddenly if the dam breaks causing flood and debris flow with high chances of huge loss of life, infrastructure and biodiversity of the region and downstream. Therefore, more studies on glaciers and glacial lakes are very essential toge

Bounds on the calving cliff height of marine terminating glaciers

AbstractIncreased calving and rapid retreat of glaciers can contribute significantly to sea level rise, but the processes controlling glacier retreat remain poorly understood. We seek to improve our understanding of calving by investigating the stress field controlling tensile and shear failure using a 2‐D full‐Stokes finite element model. Using idealized rectangular geometries, we find that when rapidly sliding glaciers thin to near buoyancy, full thickness tensile failure occurs, similar to observations motivating height‐above‐buoyancy calving laws. In contrast, when glaciers are frozen to their beds, basal crevasse penetration is suppressed and calving is minimal. We also find that shear stresses are largest when glaciers are thickest. Together, the tensile and shear failure criteria map out a stable envelope in an ice‐thickness‐water‐depth diagram. The upper and lower bounds on cliff height can be incorporated into numerical ice sheet models as boundary conditions, thus bracketing the magnitude of calving rates in marine‐terminating glaciers.

Glacier‐based climate reconstructions for the last glacial–interglacial transition: Arthur's Pass, New Zealand (43°S)

ABSTRACTGeological records of mountain glacier fluctuations provide useful evidence for tracing the magnitude and rate of past temperature change. In this study, we present air temperature reconstructions for the last glacial termination in New Zealand derived using snowline reconstructions and numerical glacier modelling. We target the Arthur's Pass moraines in the Otira River catchment, which have previously been dated to the Lateglacial using cosmogenic 10Be. Recalculation of these exposure ages using a locally calibrated 10Be production rate indicates that these moraines formed ca. 16–14 ka. Our glacier modelling experiments and snowline reconstructions exhibit good agreement and show that the Arthur's Pass moraines formed in a climate that was 2.2–3.5 °C colder than present. Combining our results with other, proximal glacier records shows that ice in this catchment retreated ca. 50 km from the coastal plain to the main divide during the interval 17–15 ka, in response to a temperature increase of at least ca. 3 °C. Over half of this retreat occurred after the glacier had withdrawn from an overdeepened basin. Thus, we conclude that temperature increase was the primary driver of widespread and rapid glacier retreat in New Zealand at the onset of the last glacial termination.

Diurnal dynamics of minor and trace elements in stream water draining Dongkemadi Glacier on the Tibetan Plateau and its environmental implications

Global warming has resulted in rapid glacier retreat on the Tibetan Plateau (TP), and the impacts of glacier melting on downstream ecosystems remain largely unknown. Minor and trace elements in stream water draining Dongkemadi Glacier (DG) were examined during the ablation season of 2013. Dominant ions and elements are HCO3−, Ca2+, Fe and Sr. Water chemistry is controlled by the weathering of calcite, oxidation of pyrite and dissolution of evaporites. Correlations suggests the hydrological (e.g. meltwater generation and routing, water residence time) and physicochemical (e.g. sorption, precipitation, oversaturation) controls on species concentrations. The distribution of metals is featured by the mixture of soluble metal and non-metal ligand complexes and free monovalent and divalent ions. Downstream increased concentrations and/or fluxes of some metals and metalloid (e.g. Cr, Cu and As) suggest potential environmental impacts. Discharge-normalized cation denudation rate (372Σ∗meq+m−3) in the DG basin is larger than those from alpine and polar glaciers, suggesting a stronger weathering of carbonate with greater abundance on the TP in comparison to other mountain and polar glacial catchments. The maximum Fe concentration exceeds the USEPA guideline, and Al, Zn and Pb are close to or of the same order of magnitude as liminal values. This implies that the TP may face a challenge of ecosystem health and environmental issue in a warming climate.

Recent glacier and glacial lake changes and their interactions in the Bugyai Kangri, southeast Tibet

AbstractGlaciers in the Bugyai Kangri are located in a transition zone from southeast Tibet, where monsoonal temperate glaciers dominate, to inner Tibet, where continental glaciers dominate. Here we analyze glacier and glacial lake changes in this region using multi-year inventories based on Landsat images from 1981–2013. Results show that the total area of 141 glaciers in the region decreased by 30.44 ±0.89 km2from 198.35 ±9.54 km2(1980s) to 167.93 ±4.52 km2(2010s). The annual area shrinkage rate (–0.48% a–1) is lower than that reported for southeastern Tibet but higher than that of inner Tibet. Both the number and total area of glacial lakes increased between 1981 and 2013. Among all lakes, proglacial lakes contribute most (~81 %) to the expansion. The total area of ten proglacial lakes increased by 150.3 ± 13.17% and of these ten lakes the four that expanded most sharply showed increased calving at their upper margins, resulting in more rapid retreat of lake-terminating glaciers than land-terminating glaciers. Owing to rapid calving, several lakes may undergo further growth in the near future, increasing the potential risk of glacial lake outburst floods.

Glacier–groundwater stress gradients control alpine river biodiversity

AbstractIn alpine river networks, water source (i.e. snow, ice or groundwater) plays a major role in influencing flow regimes, benthic habitat and macro‐invertebrate community structure. Across these systems, a natural stress gradient can be conceptualized, from rivers fed exclusively by meltwater (harsh habitat) to those with no melt input (relatively benign, groundwater fed). However, despite the current context of rapid glacier retreat, our understanding of linkages between meltwater contributions, physico‐chemical habitat and biodiversity remains limited. To address this research gap, habitat characteristics and macro‐invertebrate community structure were studied at 26 sites (five river basins) in the French Pyrénées across a meltwater gradient from 0% to 99%. A combination of generalized regression models and multivariate analyses showed that the stress gradient was associated with the following: (i) linear responses of key physico‐chemical habitat variables, in particular bed stability, (ii) unimodal responses at the community level (e.g. richness and total density peaks at 40–60% meltwater contribution), and (iii) both unimodal and monotonic responses at the level of individual taxa. Sites characterized by high contributions of meltwater, although species poor, were important for beta diversity because of their specialist endemic fauna. Our findings suggest that continued glacier and snowpack retreat due to expected future climate change are likely to lead to more homogeneous alpine river habitats (i.e. reduced meltwater–groundwater stress gradient breadth). As a result, increased alpha diversity is expected as previously harsh habitats become more favourable; however, an associated decrease in beta diversity is likely as glacial stream specialists become replaced by generalists. Copyright © 2016 John Wiley & Sons, Ltd.

Erratum

Marine EcologyVolume 37, Issue 4 p. 929-929 ErratumFree Access Erratum This article corrects the following: Antarctic shallow water benthos in an area of recent rapid glacier retreat Francesca Pasotti, Elena Manini, Donato Giovannelli, Anne-Cathrin Wölfl, Donata Monien, Elie Verleyen, Ulrike Braeckman, Doris Abele, Ann Vanreusel, Volume 36Issue 3Marine Ecology pages: 716-733 First Published online: September 27, 2014 First published: 11 December 2015 https://doi.org/10.1111/maec.12344AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat In Pasotti et al. (2015), Fig. 11 was published with an error on page 729. The correct figure should have been: Figure 11Open in figure viewerPowerPoint Conceptual scheme of the coves' processes. For details see legend on Figure. We apologise for the error. Reference Pasotti F., Manini E., Giovannelli D., Wölfl A.-C., Monien D., Verleyen E., Braeckman U., Abele D., Vanreusel A. (2015) Antarctic shallow water benthos in an area of recent rapid glacier retreat. Marine Ecology, 36, 716– 733. Volume37, Issue4August 2016Pages 929-929 FiguresReferencesRelatedInformation

An 825-year long varve record from Lillooet Lake, British Columbia, and its potential as a flood proxy

Lillooet River in southwest British Columbia has produced damaging floods many times during the past century. The floods are recorded in Lillooet Lake, into which the river flows, as anomalously thick clastic varves. In order to determine whether an 825-year long varve record obtained from 12 percussion and vibracores can be used as flood proxy, we compare river discharge records dating back to 1914 to the thickness of the varves deposited during the same time period. Correlations between varve thickness and a variety of historical discharge measures are low to moderate for the periods 1914–2004 (r2 = 0.37) and 1914–1945 (r2 = 0.40), but higher for the period 1946–2004 (r2 = 0.55). The best correlation (r2 = 0.55) is between maximum fall discharge and varve thickness during the most recent period (1946–2004). Varve thickness for the earlier period of hydrometric data (1914–1946), which is a time of rapid glacier retreat and warmer temperatures in British Columbia, is best explained with a discharge proxy combining nival runoff, glacier runoff, and maximum fall discharge. Landslides, glacier fluctuations, river dyking, artificial lowering of Lillooet Lake, as well as lag effects of storms are responsible for the considerable unexplained variance in the relation between discharge measures and varve thickness over the historic period. The cores contain many anomalously thick varves, some of which we attribute to previously dated prehistoric landslides in the watershed or to local landslides into the lake. We conclude that many historic and prehistoric floods are faithfully recorded as anomalously thick clastic varves, but that other processes operating in the watershed preclude using this record as a reliable paleo-flood proxy.

Climate-driven changes in lakes from the Peruvian Andes

The consequences of recent warming in the Andes have been dramatic, most iconically visualized by the rapid retreat of tropical mountain glaciers. Of all the ecosystems in the tropical Andes, lakes have received amongst the least research attention. We examined subfossil diatom and chrysophyte assemblages to chronicle recent (past ~150 years) ecological change in lakes from the Peruvian Andes. We recorded abrupt increases in planktonic diatoms and scaled chrysophytes beginning in the early 1900s. These changes are consistent with enhanced periods of thermal stratification, brought on by rising temperatures that have been documented throughout the Andes. These data indicate that ecological and likely physical limnological changes associated with Anthropocene warming are already under way in tropical high mountain lakes.

Changes in glacier area and volume in Terskey Ala-Too Range in the second half of XX century

Changes in the extent of glaciers and rates of glacier termini retreat in the eastern Terskey-Alatoo Range, the Tien Shan Mountains, Central Asia have been evaluated using the remote sensing techniques. Changes in the extent of 109 glaciers between 1965, 1990 and 2003 have been estimated through the delineation of glacier outlines on the topographic maps, Landsat TM and ASTER imagery for 1965, 1990 and 2003 respectively. Glacier surface area has decreased by 12.6% of the 1965 value between 1965 and 2003. Detailed mapping of 10 glaciers using historical maps and aerial photographs from the 1943–1977 period, has enabled glacier extent variations over the 20th century to be identified with a higher temporal resolution. Glacial retreat was slow in the early 20th century but increased considerably between 1943 and 1956 and then again after 1977. The post-1990 period has been marked by the most rapid glacier retreat since the end of the LIA. For the selected 13 glaciers volume reduction has been evaluated using a time step digital elevation models. DEM obtained from the 1:25 000 topographic maps of 1965 and 1977 were compared to SRTM data. The observed changes in the extent of glaciers are in line with the observed climatic warming. The regional weather stations have revealed a strong climatic warming during the ablation season since the 1950s at a rate of 0.02–0.03 oC a-¹. At the higher elevations in the study area represented by the Tien Shan meteorological station, the summer warming was accompanied by negative anomalies in annual precipitation in the 1990s enhancing glacier retreat. However, trends in precipitation in the post-1997 period cannot be evaluated due to the change in observational practices at this station. Neither station in the study area exhibits significant long-term trends in precipitation.

Late Pleistocene to Holocene palaeoenvironmental variability in the north-west Spanish mountains: insights from a source-to-sink environmental magnetic study of Lake Sanabria

We present a source-to-sink environmental magnetic study of a sediment core from Lake Sanabria (north-west Iberian Peninsula) and rocks of its catchment. The results indicate the occurrence of magnetite, and probably also pyrrhotite, in sediments accumulated between ca. 26 and 13 cal ka BP in a proglacial lake environment. These minerals also appear to dominate the magnetic assemblage of Palaeozoic rocks from the lake catchment. This indicates that sedimentation was then driven by the erosion of glacial flour, which suffered minimal chemical transformation due to a rapid and short routing to the lake. A sharp change in magnetic properties observed in the lake sediments between 13 and 12.6 cal ka BP reflects the rapid retreat of glaciers from the lake catchment. Sediments from the upper half of the studied sequence, accumulated after 12.6 cal ka BP in a lacustrine environment with strong fluvial influence, contain magnetite and smaller amounts of maghemite and greigite. We suggest that greigite grew authigenically under anoxic conditions caused by enhanced accumulation of organic matter into the lake. The occurrence of maghemite in these sediments suggests pedogenic activity in the then deglaciated lake catchment before the erosion and transportation of detrital material into the lake.

Rapid glacier retreat in the Naimona’Nyi region, western Himalayas, between 2003 and 2013

The Northern Hemisphere experienced its warmest temperatures in the early 21st century, and this clearly increased glacier melting on the Tibetan Plateau. This study analyzed the glacier change in the area, their terminus positions and surface elevations over the last decade (2003 to 2013) in the Naimona'Nyi region of the western Himalayas, by comparing remote sensing data and differential global position system (dGPS) data from in situ surveys. The results show an accelerating glacier retreat over the past decade in this region. The area covered by glaciers was reduced by a total of 13.2 � 0.0022 km 2 over this period. The terminus of the Naimona'Nyi main glacier studied in the paper retreated by over 191 � 35 m. We also compared the ice cloud and elevation satellite elevation data with in situ measured decimeter accuracy dGPS elevation data, thus providing changes in glacier surface elevations in different periods. The maximum measured glacier thinning rate reached to 0.58 � 0.06 m∕a between 2009 and 2013. In addition to the dependence on elevation and glacier size, we found a larger retreat on the north facing slopes than on the south facing slopes in the region. Meteorological data show that glacier changes within the study area can probably be attributed to the observed rapid temperature rise. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI. (DOI: 10.1117/1.JRS.8.083508)

Antarctic shallow water benthos in an area of recent rapid glacier retreat

AbstractThe West Antarctic Peninsula is one of the fastest warming regions on Earth. Faster glacier retreat and related calving events lead to more frequent iceberg scouring, fresh water input and higher sediment loads, which in turn affect shallow water benthic marine assemblages in coastal regions. In addition, ice retreat creates new benthic substrates for colonization. We investigated three size classes of benthic biota (microbenthos, meiofauna and macrofauna) at three sites in Potter Cove (King George Island, West Antarctic Peninsula) situated at similar water depths but experiencing different disturbance regimes related to glacier retreat. Our results revealed the presence of a patchy distribution of highly divergent benthic assemblages within a relatively small area (about 1 km2). In areas with frequent ice scouring and higher sediment accumulation rates, an assemblage mainly dominated by macrobenthic scavengers (such as the polychaete Barrukia cristata), vagile organisms and younger individuals of sessile species (such as the bivalve Yoldia eightsi) was found. Macrofauna were low in abundance and very patchily distributed in recently ice‐free areas close to the glacier, whereas the pioneer nematode genus Microlaimus reached a higher relative abundance in these newly exposed sites. The most diverse and abundant macrofaunal assemblage was found in areas most remote from recent glacier influence. By contrast, the meiofauna showed relatively low densities in these areas. The three benthic size classes appeared to respond in different ways to disturbances likely related to ice retreat, suggesting that the capacity to adapt and colonize habitats is dependent on both body size and specific life traits. We predict that, under continued deglaciation, more diverse, but less patchy, benthic assemblages will become established in areas out of reach of glacier‐related disturbance.

Population structure and dynamics of Arctic willow (Salix arctica) in the High Arctic

AbstractAimAlterations to the abundance and distribution of plants, especially shrubs, have been predicted by warming experiments and confirmed by remote‐sensing analyses and land‐based observations in the Low Arctic. In the High Arctic, analyses of satellite images suggest a recent increase in the normalized difference vegetation index (NDVI) and warming experiments have shown a positive correlation between temperature and shrub cover, but little is known about the responses of natural systems. In this context, we investigated populations of Arctic willow (Salix arcticaPall.) to assess the potential contribution of this structuring species to High Arctic shrubification.LocationSeven polar semidesert sites, including two glacier forelands, in High Arctic Canada and Greenland.MethodsWe evaluated the size distribution and establishment age of Arctic willow populations through field measurements and dendrochronological analysis. We also assessed the cover of Arctic willow at each site and compared current data with historical records.ResultsAge determination of over 200 large individuals established by seed suggests that colonization events were associated with the melting of permanent snow and glacial ice. Size distributions showed that recent recruitment was more frequent on glacier forelands, even though seedling establishment was common in other sites. Comparing our measurements with previous studies at the same sites revealed that significant increases in cover over the past few decades occurred only on glacier forelands.Main conclusionsOur results suggest that the population structure and dynamics of Arctic willow in the High Arctic are influenced by site‐specific factors. Rapid glacier retreat is increasing the extent of the glacier forelands, which are currently experiencing relatively rapid plant colonization. Some sheltered sites with greater snow accumulation will probably experience increased shrub colonization under current and predicted climate change. It appears, however, that shrub recruitment and growth are still strongly limited by water availability, and the reduction in permanent snow cover may exacerbate this stress.

Sector of West Antarctic Ice Sheet in “Irreversible Retreat”

A large sector of the West Antarctic Ice Sheet “has gone into a state of irreversible retreat,” according to glaciologist Eric Rignot, lead author of the paper “Widespread rapid grounding line retreat of Pine Island, Thwaites, Smith, and Kohler Glaciers in West Antarctica from 1992 to 2011,” which has been accepted for publication in Geophysical Research Letters (GRL).

Direct measurement of glacier thinning on the southern Tibetan Plateau (Gurenhekou, Kangwure and Naimona’Nyi glaciers)

AbstractNumerous studies have confirmed the rapid retreat of Tibetan Plateau glaciers in recent decades, and resulting reductions in glacier volume. However, high-resolution determinations of the changes in glacier thickness remain sparse. This paper presents results based on differential GPS measurements to accurately measure glacier thickness change over the past few years. Measurements from the lower part of Gurenhekou glacier show an average thickness change of –3.82 m over a 4 year period. On the lower part of Kangwure glacier we measured an average thickness change of –2.70 m over 3 years. On the upper part of Naimona’Nyi glacier (northern branch), western Himalaya, thickness changed by –1.34 m on average between 2008 and 2010, and –0.87 m between 2010 and 2013. Large temporal changes in thinning rates were found on Naimona’Nyi glacier, due to variations in local precipitation. Our measurements also show variable changes in glacier thickness over different parts of each glacier, with little dependence on elevation. The limited data also show glacier thinning in the accumulation zone.

Bacterial structures and ecosystem functions in glaciated floodplains: contemporary states and potential future shifts

Glaciated alpine floodplains are responding quickly to climate change through shrinking ice masses. Given the expected future changes in their physicochemical environment, we anticipated variable shifts in structure and ecosystem functioning of hyporheic microbial communities in proglacial alpine streams, depending on present community characteristics and landscape structures. We examined microbial structure and functioning during different hydrologic periods in glacial (kryal) streams and, as contrasting systems, groundwater-fed (krenal) streams. Three catchments were chosen to cover an array of landscape features, including interconnected lakes, differences in local geology and degree of deglaciation. Community structure was assessed by automated ribosomal intergenic spacer analysis and microbial function by potential enzyme activities. We found each catchment to contain a distinct bacterial community structure and different degrees of separation in structure and functioning that were linked to the physicochemical properties of the waters within each catchment. Bacterial communities showed high functional plasticity, although achieved by different strategies in each system. Typical kryal communities showed a strong linkage of structure and function that indicated a major prevalence of specialists, whereas krenal sediments were dominated by generalists. With the rapid retreat of glaciers and therefore altered ecohydrological characteristics, lotic microbial structure and functioning are likely to change substantially in proglacial floodplains in the future. The trajectory of these changes will vary depending on contemporary bacterial community characteristics and landscape structures that ultimately determine the sustainability of ecosystem functioning.

Regeneration of Little Ice Age bryophytes emerging from a polar glacier with implications of totipotency in extreme environments.

Across the Canadian Arctic Archipelago, widespread ice retreat during the 20th century has sharply accelerated since 2004. In Sverdrup Pass, central Ellesmere Island, rapid glacier retreat is exposing intact plant communities whose radiocarbon dates demonstrate entombment during the Little Ice Age (1550-1850 AD). The exhumed bryophyte assemblages have exceptional structural integrity (i.e., setae, stem structures, leaf hair points) and have remarkable species richness (60 of 144 extant taxa in Sverdrup Pass). Although the populations are often discolored (blackened), some have developed green stem apices or lateral branches suggesting in vivo regrowth. To test their biological viability, Little Ice Age populations emerging from the ice margin were collected for in vitro growth experiments. Our results include a unique successful regeneration of subglacial bryophytes following 400 y of ice entombment. This finding demonstrates the totipotent capacity of bryophytes, the ability of a cell to dedifferentiate into a meristematic state (analogous to stem cells) and develop a new plant. In polar ecosystems, regrowth of bryophyte tissue buried by ice for 400 y significantly expands our understanding of their role in recolonization of polar landscapes (past or present). Regeneration of subglacial bryophytes broadens the concept of Ice Age refugia, traditionally confined to survival of land plants to sites above and beyond glacier margins. Our results emphasize the unrecognized resilience of bryophytes, which are commonly overlooked vis-a-vis their contribution to the establishment, colonization, and maintenance of polar terrestrial ecosystems.

Glacier changes and climate trends derived from multiple sources in the data scarce Cordillera Vilcanota region, southern Peruvian Andes

Abstract. The role of glaciers as temporal water reservoirs is particularly pronounced in the (outer) tropics because of the very distinct wet/dry seasons. Rapid glacier retreat caused by climatic changes is thus a major concern, and decision makers demand urgently for regional/local glacier evolution trends, ice mass estimates and runoff assessments. However, in remote mountain areas, spatial and temporal data coverage is typically very scarce and this is further complicated by a high spatial and temporal variability in regions with complex topography. Here, we present an approach on how to deal with these constraints. For the Cordillera Vilcanota (southern Peruvian Andes), which is the second largest glacierized cordillera in Peru (after the Cordillera Blanca) and also comprises the Quelccaya Ice Cap, we assimilate a comprehensive multi-decadal collection of available glacier and climate data from multiple sources (satellite images, meteorological station data and climate reanalysis), and analyze them for respective changes in glacier area and volume and related trends in air temperature, precipitation and in a more general manner for specific humidity. While we found only marginal glacier changes between 1962 and 1985, there has been a massive ice loss since 1985 (about 30% of area and about 45% of volume). These high numbers corroborate studies from other glacierized cordilleras in Peru. The climate data show overall a moderate increase in air temperature, mostly weak and not significant trends for precipitation sums and probably cannot in full explain the observed substantial ice loss. Therefore, the likely increase of specific humidity in the upper troposphere, where the glaciers are located, is further discussed and we conclude that it played a major role in the observed massive ice loss of the Cordillera Vilcanota over the past decades.

Future of wetlands in tropical and subtropical Asia, especially in the face of climate change

Tropical and subtropical Asia differs from other tropical regions in its monsoonal climate and the dominant influence of the Hindukush and Himalayan mountain ranges which result in extremes of spatial and temporal variability in precipitation. However, several major rivers and their tributaries arise in the Himalayan ranges and are fed by thousands of glaciers. Huge sediment loads carried by these rivers result in important deltas at their mouths. The climatic and physiographic diversity have endowed the region with many kinds of wetlands. Of these, the peatswamps of southeast Asia constitute about 56% of the world’s tropical peatlands, and more than 42% of the world’s mangroves occur in South and southeast Asia. Among other wetlands, riverine swamps are rather restricted whereas the seasonal marshes are a dominant feature. Another characteristic feature of tropical Asia are the innumerable human-made and intensively managed wetlands of which the paddy fields and aquaculture ponds are the most extensive. Throughout tropical Asia, wetlands have been a part of the socio-cultural ethos of the people and many communities have lived in wetlands. However, the pressures of high population and the economic development have extensively impacted upon wetlands which have been transformed for paddy cultivation and aquaculture, drained and converted to other land uses for economic gains (e.g., conversion to oil palm), and degraded by discharge of domestic and industrial wastes. Invasive plant and animal species have also played a significant role. The climate change is already being felt in the rapid retreat of Himalayan glaciers, increased temperature and variability in precipitation as well as the frequency of extreme events. Sea level rise is seen as a major threat to the coastal wetlands, particularly the mangroves. Increasing droughts have caused frequent fires in Indonesian peat swamps that have further feedback impacts on regional climate. However, the actual threat to wetlands in this region arises from the extensive hydrological alterations being caused by storage, abstraction and diversion of river flows for agriculture, industry and hydropower. Currently, the state of our understanding wetlands in general, and the efforts and infrastructure for research and training in wetlands are very poor. Although a few wetlands have been designated as Ramsar sites, the policies aimed at wetland conservation are either non-existent or very weak. Human responses to greater uncertainty and variability in the available water resources in different parts of Asia will be crucial to the conservation of wetlands in the future.