This study presents the variations in temperature and precipitation as well as a GIS- and remote sensing supported analysis of in glacier changes since the end of the Little Ice Age, focusing on six valleys in northern Tien Shan with different climatic conditions and the Bernina Group/Swiss Alps. Digital elevation models (DEMs) constitute an important data base for this study. Comparisons of the SRTM3-DEM with the DHM25 of Switzerland and with DEMs generated from topographic maps show very precise elevation figures for the SRTM3-DEM, which are, however, a little too low on average. Data gaps in high mountains can be filled with ASTER data. ASTER-DEMs are of higher resolution than the SRTM3-DEM, but have higher height inaccuracies and also gaps. Regionalization of temperature and precipitation conditions as well as the modeling of potential direct solar radiation enables the different climatic conditions at glacier regions of the valleys investigated in northern Tien Shan to be determined. Trend analysis for the period from 1879 to 2000 at 16 climate stations indicates a temperature increase of about 0.8 K/100a for the period 1900 to 2000 and about 2.0 K/100a on average for the second half of the last century. The increase was due mainly to a temperature rise in autumn and winter. The increase is less pronounced in mountainous areas, but still obvious. Although the temperature increase at the the Bernina Group/Alps is, in general, similar to that of the northern Tien Shan, its development can be described as contracyclical. In terms of precipitation, there was a small increase in both areas on average, but no clear trend. The snow and ice coverage was successfully delineated using segmented TM4/TM5-ratio images of Landsat ETM+ scenes from the year 1999. However, the identification of debris-covered glacier parts poses problems. The margins of the valley glaciers become clearly visible using a morphometric analysis. The delineated glacierized areas are compared with those of the Soviet glacier inventory from the middle of the 1950s, with glacier areas from the late 1970s from topographic maps, with data from 1990 from the recent Kazakh glacier inventory and with the moraines of the Little Ice Age. As in the Alps, the trend in northern Tien Shan has been toward a strong glacier melt since the end of Little Ice Age. The mean decrease in glacier extent was in average almost 33% between 1955 and 1999 in the investigated valleys. From 1979 to 1999 there was ~20% loss of glacierized area. The average retreat is therefore slightly higher than in the Swiss Alps. This retreat is nevertheless not homogeneous, but depends strongly on the size, location and climate regime at the glaciers. On the whole, the retreat of the more maritime glaciers at the northern slope is greater than that of the more continental glaciers. This can be explained by the extended ablation period resulting from the increase in autumn temperatures. In contrast, the area loss of the continental-type glaciers with very predominant summer accumulation was in some parts conspicuously less. This is consistent with the minor increase in summer temperatures. However, under drier conditions with high solar radiation input the areal retreat of continental-type glaciers can be even more pronounced than that of more maritime glaciers. Accompanying studies on the melting of permafrost and the movement of rock glaciers also clearly indicate a temperature increase.