Mountains play an essential role in supplying water, energy, food and other services to millions of people living in the mountains and downstream. Ensuring the continued supply of these services has never been more important. However, many mountain regions are experiencing a growing solid waste problem, from ever-expanding urban sprawls and cities, increasing consumption patterns, existing and past mining operations, tourism activities and practises of illegal dumping. Steepness, remoteness, prevailing socio-economic conditions, and vulnerability to natural hazards, makes waste management in mountains more challenging than in lowland areas. Gravity and river flow can also enlarge the footprint of mountain waste to a thousand kilometres or more downstream - and even right into the ocean.