Nepalese villagers living in the shadow of Mt Langtang Lirung say the snows did not fall in their valley last February, the first time that had happened in living memory

On the outskirts of Kathmandu, capital of Nepal, climate researchers twiddle with computers displaying maps of the Himalayas. At the press of a button, rivers and mountain passes change colour and watercourses expand to show villages swept away by simulated flood waters.