Rocky peaks which to us, perhaps, seem a symbol of permanence, are more fragile than they appear.
Today in Alps, human encroachment is challenging even the highest summits.
In the Rockies, rising temperatures are shortening winter hibernation and stifling the growth of valuable food plants.
And in the Andes, some glaciers have shrunk by 50% in just 30years.
Even in Himalayas are now vulnerable. With most of the world's tallest peaks and covering a third of million square miles, this is the greatest mountain range of all. And the temperatures are now rising faster than the global average. As the snow line retreats further up these peaks, there is less and less space for wildlife.