The Guardian newspaper reported in 2011 that the Himalayas are in danger of becoming a giant garbage dump. (http://www.theguardian.com/environment/blog/2011/sep/12/himalayas-waste)
Himalayan trekking is a sport for elite mountain climbers and thrill seekers from all over the world. Despite being some of the most environmentally conscious demographic groups, mountain climbers leave a substantial amount of trash during their expeditions. With over 30,000 climbers making the trek each year, the garbage adds up quickly. Local Nepali villages do not have waste treatment systems to process the waste in their surrounding mountains furthering compounding the problem. Non-biodegradable waste absorbs heat and over time can alter the melting rate of glaciers and increasing the risk of flash flooding and rising water tables.
I think this is going to require changes by many stakeholders in society. Climbers need to be more careful in their choice of equipment and supplies, consciously avoiding non-bio gradable materials as much as possible. Equipment and supply companies need to design products with sustainability considerations as a basic design principle. Local governments who profit from tourist income must invest in more modern waste treatment facilities – that can be valuable to local communities as well. And the media should continue to report news stories to change hearts and minds.