It was a disaster when the glacial lake burst its banks - Residents in a place called Hassan Abad in the mountains of north Pakistan are still picking up the pieces after much of their village was destroyed in a flood back in May.

The government in Pakistan says 33 such lakes are at risk of overflowing, with potentially devastating consequences.

Three of the world's most spectacular mountain ranges intersect in Pakistan’s north - the Hindu Khush, the Karakoram and the Himalayas - forming the largest reservoir of ice outside the poles. The country's mountainous north is home to more than 7,000 glaciers.

A climatologist explains on why glaciers are melting at such a rapid rate, and what if anything can be done to prevent the next catastrophe.