Search

The cryosphere in mountain regions is rapidly declining, a trend that is expected to accelerate over the next several decades due to anthropogenic climate change. A cascade of effects will result, extending from mountains to lowlands with associated impacts on human livelihood, economy, and ecosystems. With rising air temperatures and increased radiative forcing, glaciers will become smaller and, in some cases, disappear, the area of frozen ground will diminish, the ratio of snow to rainfall will decrease, and the timing and magnitude of both maximum and minimum streamflow will change. These changes will affect erosion rates, sediment, and nutrient flux, and the biogeochemistry of rivers and proglacial lakes, all of which influence water quality, aquatic habitat, and biotic communities. Changes in the length of the growing season will allow low-elevation plants and animals to expand their ranges upward. Slope failures due to thawing alpine permafrost, and outburst floods from glacier-and moraine-dammed lakes will threaten downstream populations.Societies even well beyond the mountains depend on meltwater from glaciers and snow for drinking water supplies, irrigation, mining, hydropower, agriculture, and recreation. Here, we review and, where possible, quantify the impacts of anticipated climate change on the alpine cryosphere, hydrosphere, and biosphere, and consider the implications for adaptation to a future of mountains without permanent snow and ice.

Nearly all of what is now British Columbia and adjacent areas were covered by an ice sheet at the maximum of the Last Glaciation (MIS 2) about 18,000 years ago. By 11,000 years ago, the Cordilleran Ice Sheet had disappeared, a victim of warming climate, eustatic sea-level rise along its western margin, and perhaps a reduction in precipitation. Deglaciation proceeded by frontal retreat at the periphery of the ice sheet and by downwasting, complex frontal retreat, and localized stagnation in its interior areas. The chronology of deglaciation is constrained, albeit with inherent dating errors, by AMS radiocarbon and 10Be surface exposure ages. High-elevation sites at the western margin of the British Columbia Interior Plateau, east of the Coast Mountains, became ice-free between about 15,000 and 12,000 years ago. Ice cover in the southern Coast Mountains was sufficiently extensive during the Younger Dryas Chronozone (12,900-11,700 years ago) that glaciers advanced into low-lying areas north and east of Vancouver. At the same time, however, a labyrinth of dead or dying tongues of glacier ice covered some interior valleys. By 11,000 years ago, ice cover in the Canadian Cordillera was no more extensive than it is today., Casi todo lo que hoy es Columbia Británica y áreas adyacentes estuvieron cubiertas por un manto de hielo durante el máximo de la Última Glaciación (MIS 2) hace unos 18.000 años. Hace unos 11.000 años el manto de hielo de la cordillera había desaparecido, víctima del calentamiento climático, el ascenso eustático del nivel del mar en su margen occidental, y quizás una reducción de la precipitación. La deglaciación se produjo por retroceso frontal en la periferia del manto de hielo y por desmantelamiento, retroceso frontal complejo, y estancamiento local en áreas del interior. La cronología de la deglaciación está bien definida, aunque con inherentes errores de datación, mediante radiocarbono por AMS y edades de exposición superficial mediante 10Be. Los lugares elevados en el margen occidental de la Llanura Interior de Columbia Británica, al este de las montañas de la Costa, quedó libre de hielo entre 15.000 y 12.000 años BP. La cubierta de hielo en el sur de las Montañas de la Costa fue suficientemente extensa durante el Younger Dryas (12.900-11.700 años BP), de manera que los glaciares avanzaron hacia áreas bajas del norte y este de Vancouver. A la vez, sin embargo, un laberinto de lenguas glaciares muertas o moribundas cubrieron algunos valles del interior. Hace 11.000 años la masa de hielo en la Cordillera de Canadá no era más extensa de lo que es hoy.

Methamphetamine (MA) users are assumed to have a high burden of tooth decay. Less clear is how the distribution and severity of dental caries in MA users differ from the general population. Using a covariate-balancing propensity score strategy, we investigated the differential effects of MA use on dental caries by comparing the patterns of decayed, missing, and filled teeth in a community sample of 571 MA users with a subset of 2,755 demographically similar control individuals selected from a National Health and Nutrition Examination Survey (NHANES) cohort. Recruited over a 2-y period with a stratified sampling protocol, the MA users underwent comprehensive dental examinations by 3 trained and calibrated dentists using NHANES protocols. Propensity scores were estimated with logistic regression based on background characteristics, and a subset of closely matched subjects was stratified into quintiles for comparisons. MA users were twice as likely to have untreated caries (odds ratio [OR] = 2.08; 95% confidence interval [95% CI]: 1.55 to 2.78) and 4 times more likely to have caries experience (OR = 4.06; 95% CI: 2.24 to 7.34) than the control group of NHANES participants. Additionally, MA users were twice as likely to have 2 more decayed, missing, or filled teeth (OR = 2.08; 95% CI: 1.29 to 2.79) than the NHANES participants. The differential involvement of the teeth surfaces in MA users was quite distinctive, with carious surface involvement being highest for the maxillary central incisors, followed by maxillary posterior premolars and molars. Users injecting MA had significantly higher rates of tooth decay compared with noninjectors (P = 0.04). Although MA users experienced decayed and missing dental surfaces more frequently than NHANES participants, NHANES participants had more restored surfaces, especially on molars. The high rates and distinctive patterns of dental caries observed could be used 1) to alert dentists to covert MA use in their patients and 2) as the

Climate change and increased skier density is increasing ski run reworking, use of artificial snow and snow grooming. Few studies are available on these engineering impacts on slope stability. Therefore, the soil properties, compaction and infiltration characteristics were investigated on ski slopes and compared to natural sites for three different ski resorts (Les Menuires, La Rosière and Foppolo) in the French and Italian Alps. The results show that soil properties differ substantially, with lower nitrogen and carbon content and higher pH on ski runs. Soil compaction is up to three times higher and infiltration takes up to four times longer on ski slopes compared to natural sites. Some new ski slopes were even 100 % impermeable. This explains why ski slopes are more prone to landslides, sheet, rill and gully erosion and have a distinct vegetation cover.