When explorer Will Gadd set out to climb ice on every continent in the world 10 years ago, he assumed he would have plenty of time to accomplish his goal. With only Africa and Antarctica left on his to-climb list, however, the professional free climber and National Geographic Adventurer of the Year recently discovered that he would have to act sooner than he thought.

“I’d seen pictures of the ice on Kilimanjaro — and there are other peaks in Africa that have ice too — and I thought ‘I’ll get around to that one day, glaciers are there forever, they don’t go away,’” he said. “It didn’t really hit me until I started reading research papers on Africa, and one of them said the ice on Kilimanjaro could be gone in as little as five years.”

Arriving at the peak of the tallest mountain in Africa last October, Gadd could hardly believe that the massive ice structures he’d seen in recent pictures were the same as the small frozen formations that greeted him.

“The ice that I had pictures of wasn’t there, it was gone. The things I planned to climb were gone,” he said. “It was really striking to stand on top of the mountain and look around and feel this absence of ice.”

Approximately 85% of the glacial ice on Mount Kilimanjaro disappeared between 1912 and 2011, and the remainder could disappear before 2020, according to a 2012 report by Nasa. These are the same glaciers that survived three periods of abrupt climate change thousands of years ago, the most recent of which brought with it a 300 year drought starting in 2200 BC.

Traversing such delicate terrain presented its own challenges for Gadd and his team. Gadd says that he could feel the ice shifting in the sands as he climbed some of the smaller structures, his own body weight almost enough to topple the crumbling ice towers.

“I didn’t want them to fall over on me and I’d get squished like a fly under a book or something,” said the 47-year old, who has nearly 30 years of ice climbing experience. “I’ve spent a lot of time doing this and a lot of time judging the quality of ice, and I felt like it was pushing things a bit at times.”

Having grown up in Canmore, Alberta, the province that’s home to Canada’s oil and gas industry and controversial oil sands extraction, Gadd was never “on the global warming bandwagon,” at least not until he saw it happening before his own eyes.

“We were climbing ice that is easily 10,000 years old and isn’t going to be there next week,” he said. “We camped up on top of Kilimanjaro for about five days, and some of the things we climbed on, we came back and they had fallen over.”

Now Gadd is determined to share his story in hopes of inspiring environmental action.

“Everywhere I go in the world things are changing fast in a way that they probably haven’t changed in human history,” he said. “It has politicised me.”

The pictures Gadd captured during his travels were initially intended as souvenirs for his four- and seven-year-old children, but now he hopes to find a wider audience. Gadd suspects that much of the ice he climbed in October has since disappeared, and likens those images to documenting a species just before its extinction.

“I think showing these pictures will help convince the doubters,” he said. “Anybody who sees them has to ask the question, ‘why does it look like this?’”