Tropical glaciers are both highly sensitive indicators of global climate and fresh water reservoirs in some fast developing regions. This book gives a theoretical, and practical analysis of tropical glaciology including a useful definition of tropical glacier climate regimes and the analysis of the main glaciological key variables. The Rwenzori and the Cordillera Blanca are investigated as examples of tropical glacierized mountains. The fluctuations of their glaciers since the end of the Little Ice Age are reconstructed and the probable climatic reasons are discussed: The evidence of great expansions of mountain glaciers throughout the tropics on several occasions during the Quaternary is summarized, examined and then applied and contrasted. The accompanying map of the Rwenzori Mountains National Park at a scale of 1:100 000 shows the spectacular retreat of the glaciers during the last century, and their extensions over half the area of the Park in the last 300 000 years.