Last May record temperatures provoked a GLOF or glacial lake outburst flood in northern Pakistan, sweeping away bridges and villages in the valley below the Shisper glacier. Higher up the mountains, a semi-nomadic people called the Wakhi were leading their yaks to summer pastures 15,500 feet above in the mountains. Their traditional lifestyle has also been heavily impacted by climate change. From the K2 and the Himalayas, we profile the scientists,mountain climbers, and the villagers on this global warming frontline.

• Documentary