BEIJING — Glaciologists in China and elsewhere have said for years that climate change is the main cause of glacier erosion, which threatens the water sources of much of humanity.

Officials in the far northwestern Chinese region of Xinjiang now say another factor is putting the fragile glaciers at risk: tourism.

The Xinjiang government announced this month that it was banning tourism on glaciers across the region, which is one-sixth of the Chinese land mass. Many glaciers are found in Xinjiang, and in the Tianshan range in particular, which runs east-west through the middle of the vast region.

Officials want to ensure that tourists observe the glaciers from a distance, not atop the glaciers themselves, according to a report published on Thursday by Xinhua, the state news agency.