BBC: A study of approximately half of the glaciers in the Andes mountain range shows that they are melting more quickly now than at any other time in the last 300 years. Antoine Rabatel of the Laboratory for Glaciology and Environmental Geophysics in Grenoble, France, and his colleagues blame the melting on the 0.7 °C local average temperature increase that occurred between 1950 and 1994. They have also found that the melting is most significant at lower altitudes. Below 5400 m, the glaciers have lost an average of 1.35 m of thickness per year since the 1970s, twice the rate of glaciers at higher altitudes. Because the lower glaciers have a maximum thickness of just 40 m, they will likely completely disappear in the next decades. That may have a severe impact on major cities that depend on the glaciers for fresh water. La Paz, Bolivia, for example, receives 15% of its water from glaciers during the rainy season, and 27% during the dry season.