WHILE THE SEARING HOT ASPHALT, DRIPPING AIR CONDITIONERS and withering plants might have caused many in Western Canada to look longingly at the region’s cool mountains during the historic heat dome in June 2021, even those seemingly frosty summits were starting to sweat.
It’s common to think of mountains as stationary features in a landscape, but as Dr. Lael Parrott points out, in their own longer time scales mountains are not constant, but constantly changing. With extreme events like 2021’s heat dome and the continuing effects of climate change, that change is becoming more visible.
Dr. Parrott is a Professor of Sustainability at UBC Okanagan and co-editor of the Alpine Club of Canada’s State of the Mountains report, an annual publication dedicated to drawing attention to changes in Canada’s alpine environments. Climate change has been a strong recurrent theme and this year’s report is no different, with the high temperatures from 2021’s heat dome causing far-reaching effects.
One of the most dramatic impacts was the flooding of the world-renowned Berg Lake Trail in Mount Robson Provincial Park. With the uninterrupted days of record-breaking heat in June, snow melt from the Robson Glacier flooded the Robson River’s banks, not only in the usual places but also in areas where the river hadn’t flooded before. By June 30, the worst of the heat dome was over, but half of the trail was under more than 50 centimetres of water. Other areas that weren’t flooded had significant cracks. BC Parks closed the trail and began supporting approximately 250 hikers as they made their way out.
Then, a massive thunderstorm hit on July 1. Hail and lightning exploded over the area, along with over 20 centimetres of rain in a six-hour period, which raised the river six metres. Over 50 hikers further up the trail needed to be evacuated by helicopter with the help of search-and-rescue teams.
For the rest of the season, the Robson River kept shifting across the valley. BC Parks staff built temporary bridges but in days and even hours, these structures were washed out, while many of the usual bridges had only dry earth underneath. The Berg Lake Trail remained closed over the 2022 season and will take years to rebuild.
Rivers are often thought of as static landmarks on our human-made maps, but Dr. Parrott points out that the Robson River’s significant course change as it spilled across the valley is proof of how dynamic the landscape is—and how humans will need to learn to adapt.
Similarly, the report details how the heat dome crumbled the last hope of permanently preserving the Abbot Pass Refuge Cabin. The historic cabin, which was built by Swiss guides in 1922, sat at 2,925 metres above sea level in the Rocky Mountains, straddling the provincial border near Lake Louise. While work had begun in 2018 to address slope instability underneath the cabin as the permafrost thawed, the extreme heat in 2021 accelerated the process.
“That permafrost was like ice glue holding all the rocks together,” says Dr. Parrott.
Without that ice holding firm under the cabin’s foundation, the slope was too unstable for anchors to help permanently preserve the cabin as planned. The cabin’s masonry was also cracked. When the hut was taken down from the mountain for safety reasons in 2022, workers found enough cracks and failures to suggest the hut’s entire structure was compromised.
“Ice is melting everywhere, and exponentially faster,” says Dr. Parrott. The report notes that between 2011 and 2020, Western Canada’s glacier ice shrunk by 340 square kilometres per year, which is seven times faster than the rate of glacier loss from 1984–2010. This significant melt will dramatically impact not just the mountains but also freshwater habitats and downstream water availability.
Other highlights of the report, which is available online, include articles on the bison reintroduction program led by the Stoney Nakoda Nation, an exciting fossil discovery in the Mackenzie Mountains, drilling of a 327-metre deep ice core from the top of Mount Logan and the knowledge-sharing iNaturalist project where climbers can send alpine photos to experts.
The State of the Mountains report is now in its fifth year and has received international recognition from its 2022 nomination for the UIAA Mountain Protection Award. The report has often featured extreme events like the heat dome, including the effects of dramatic wildfires and avalanches, amid coverage of how changing temperatures or snow levels are affecting other living creatures like salmon and mountain goats.
Dr. Parrott says humans can expect extreme weather events to happen more and more often as the Earth warms and climate patterns that have persisted for thousands of years begin to shift.
“The lesson to us humans is to explore resilience, not in the sense of ‘build stronger, build bigger’ but in terms of how do we retreat and leave space for the mountains, for rivers, for the environment to be dynamic and to adapt to the kinds of changes that are occurring?”
*main photo courtesy of Natasha Ewing.