Video report by ITV News Royal Editor Chris Ship
The vast mountain ranges of the Hindu Kush, take in some of the world’s greatest peaks, like Everest and K2, and yet even here, in this remote and rugged landscape, you cannot escape the impact of man-made climate change.
It was the reason why the Duke and Duchess of Cambridge boarded a helicopter early this morning, and flew from Islamabad to the rugged northern region of Pakistan.
The scenery is breathtaking. And it’s an area of this country which the world rarely sees.
But William and Kate are here to see a glacier which is in retreat.
It is melting because the planet is warming.
The couple have never before seen a melting glacier in person and they asked to come here to show what Kensington Palace called "the very real consequences of global warming".
It’s a remote corner of the world, on the border with Afghanistan, which will only ever make the news for security reasons - this is where the Pakistan Army has been fighting those loyal to al-Qaeda and the Taliban.
But for the people who live here, their lives are already being affected by climate change.
They might live in one of the most isolated parts of Asia - but the melting glaciers are causing flash floods.
And the flash floods are causing real damage to their villages and their farmland - on which their livelihoods depend.
Prince William said it was "really important" for the couple to travel to Pakistan to use their voice to talk about climate change.
"We have seen around the world now, the young are getting very engaged with what's going on, I think it's fantastic we can come together and have a really good conversation about what we need to do and action needs to happen," he said.
At a time when, across the UK, protesters from Extinction Rebellion are demanding more action to combat climate change - here is a very real example of what planetary warming is doing.
These are rural people who are doing very little to cause climate change - but they are suffering from its consequences.
A flash flood in 2015 caused severe damage in the remote valleys of the Chitral region - so William and Kate will see how the villagers are having to change their way of life to prevent people being killed by the floods.
In the West, we have focused a lot on the terrorism which has plagued Pakistan for many years.
Last night, Prince William paid his respects to all those who had "endured such sacrifice" but he also spoke of the alarming impact of temperature increases in “northern Pakistan’s highest mountains.”
“This could lead to a loss of over a third of these vital glaciers in less than a century,” William warned in a speech.
He spoke of the threats to a “critical water store for a quarter of a billion people” and the impact that will have on farming and electricity generation.
Duke and Duchess of Cambridge greeted by the Kalash people in Chitral with traditional dancing
The warning by the Duke of Cambridge today reinforces similar ones his brother Prince Harry made in Africa a few weeks ago - when he spoke of how humans are to blame for much of the world’s problems.
And William and Harry’s father, the Prince of Wales, has been making similar warnings about man’s impact on the natural world for decades.
It means three very senior members of the Royal Family are making climate change one of their main priorities.
Despite their strictly apolitical role, they seem determine to lead in the hope that politicians might follow.