The Himalaya is one of the fastest changing regions of the world due to global warming. The mountains mighty glaciers, the source of large and important rivers such as the Ganga, Indus and Brahmaputra, are melting. In February 2009, Chinese scientists warned that glaciers on the Tibetan plateau are melting at a "worrisome speed", threatening South Asia's water supply. In spite of this dramatic trend, the governments of India, Pakistan, Nepal and Bhutan want to build hundreds of mega-dams to generate electricity from the waters of the Himalayas.