Watch the retreat of glaciers up the Rocky Mountain slopes

Monday Dec. 10 is International Mountain Day, where we appreciate the majesty of towering peaks. Now, you can explore the Canadian Rocky Mountains through time thanks to aproject that shows how much our mountains have changed over the last 150 years.

The Mountain Legacy Project draws on ahistoric archive of thousands of photographs taken by dozens of mountain surveyors between 1861 and 1958, who carefully photographed and documented the majority of peaks in Canada's Rocky Mountains as well some in the northern U.S. The images make up the largest systematic collection of mountain photographs in the world.

Since 1998, in what began at the University of Alberta and is now at the University of Victoria, studentshave gone back to the exact locations where those historical photos were taken and come up with 7,000 matching photos using modern equipment. Through the use of a graphics tool, viewers can overlay past and present photos to see the changes that have taken place in the mountain environment over the last century and a half.

Comparing past and present photos taken on the exact same spot shows not only the incredible retreat of glaciers and snowcaps, but also the migration of vegetation up the slopes. What were once ice-filled valleys are now dry, while barren alpine slopes are now covered in green.

Mountains, like the polar ice caps, act as canaries in the coal mine for climate change. Because of their height, they experience many different climate zones all the way from valley to peak, so any changes to those zones are easily visible.

The Canadian Rockies are among the most spectacular in the world. The Icefields Parkway,connecting Banff and Jasper National Parks, offers a breathtaking journey up to the realm of ice and rock. It is one of the few places on the planet where you can drive right up to, and even on top of a glacier. Every Canadian should see the Rockies at least once in their life.

The Rocky Mountains date back to the time of the dinosaurs, with their sharply sculpted slopes and U-shaped valleys telling a tale of multiple ice ages that came and went, with vast glaciers that completely filled those valleys almost all the way up to the peaks. Over the last 20,000 years or so, the glaciers have been retreating as the Earth has naturally warmed. But within the last 150 years, that warming has accelerated since humans started burning fossil fuels. Now changes that took place over centuries are happening in decades.

From a personal perspective, my first visit to the Columbia Icefieldswas in 1973. Over the years since then, during every visit, I have literally watched the glacier vanish before my eyes. Last year I stood on the same spot I was on 44 years agoand looked across a vast field of gravel and meltwater towards the toe of the glacier more than a kilometre away. It has also lost a great deal of mass and sits much lower in the valley. Scientists predict the glacier could be nothing more than a few isolated patches by 2100, while thousands of other glaciers lose 80 to 90 per cent of their mass over the same period.

Mountains stand as a visible testament to human influences on the planet.

The magnificence of the mountains is best appreciated by hiking, skiing, driving, or even flying over them. If you live near mountains, go visit them on World Mountain Day, and if you cannot do that, check out the Mountain Legacy Project and see how others have seen them through the ages.