New Delhi: The glacial collapse and flash flood near the Nepal-China border are a devastating reminder of how fragile mountain environments can be, particularly in the Hindu Kush Himalayas, UN climate chief Simon Stiell said on Sunday.He said scientists and local communities have been warning for years that the Hindu Kush Himalayas are at huge risk owing to climate change."We also know a warming climate, driven by humanity burning colossal amounts of coal, oil and gas, is making tragedies like this one, and so many others around the world, much more likely, frequent and severe, with vulnerable communities often hardest hit," said Stiell, the executive secretary of the United Nations Framework Convention on Climate Change (UNFCCC).Also read: Nepal floods: Teacher evacuates 1,600 students as floods wash away Trishuli school"But the solutions to global heating are equally clear - especially a faster global shift from fossil fuels to renewables and more investment in climate resilience," he added.