Glacier retreat is one of the most dramatic manifes- tations of a warming climate. To counter its effects, arti cial ‘ice stupas’ are now being created in the Himalayas. This simple technique pipes and stores glacial meltwater in the form of huge ice cones, some 30 to 50 metres high. Their vertical shape means they melt slowly and hold long into the spring, when water shortage is normally at its most acute. As the heat rises, they feed the elds and provide much-needed drinking water until the real glacial meltwaters start owing in June.