The book shall be authored jointly by Prof. M.N. Koul and Prof. R.K. Ganjoo (both retired). Both have worked on the glaciers of NW India (Himachal Pradesh, Jammu and Kashmir and Ladakh) for 25 years. The emphasis of the research work was to understand the changes in the health of NW Himalayan glaciers with respect to the change in climate. The research was predominantly based on field investigations corroborated with application of remote sensing and GIS. The authors have published several papers in national/ international journals with high impact factors on the research studies of Himalayan glaciers. The research studies received funds from national funding agencies, e.g. Department of Science & Technology and Space Applications Centre. The authors will try to sum up the research output of about ten research projects in the form of the proposed book.