Banff Could Warm by Up to 6°C This Century, New Report Warns

A new Parks Canada climate summary projects Banff National Park's average annual temperature could rise by three to six degrees Celsius between 2051 and 2080, a level of warming expected to reshape the park's glaciers, rivers, wildlife and alpine landscapes, a Yellowstone to Yukon Conservation Initiative scientist says.

Released at the end of June, the report says the warming would bring hotter summers, shrinking snowpack, increased glacial melt and more frequent wildfires if greenhouse gas emissions continue to increase at the current rate.

Under the highest-emissions scenario, the park would see far more days above 25 C, substantially fewer days below -15 C and a frost-free season more than twice as long as during the 1961-1990 baseline period.

Graham McDowell, director of science and knowledge at the Yellowstone to Yukon Conservation Initiative, cautioned against focusing on the upper end of the projections, saying the highest-emissions scenario is intended more as a "stress test" than the most likely outcome.

"I don't think we should focus necessarily on the highest degree of warming," he said. "That's more of a stress test for when we respond, making sure that we're prepared for the worst-case scenario."

However, McDowell said the report's more moderate warming scenario remains "very considerable and very concerning" and is consistent with findings from other major climate assessments.

One of his biggest concerns is how a warmer climate will affect the park's water supply. Banff's glaciers and snowpack feed rivers that communities far beyond the park rely on for water.

"There's a really strong awareness of the role that mountains play as water towers," he said. "The dramatic changes that we've already seen in snow and ice, but more so that this report projects will continue to intensify into the future and will strongly shape hydrological systems here."

McDowell said shrinking glaciers and snowpack are expected to change how much water flows through rivers, when it arrives, how warm it is and how much sediment it carries. Those changes could affect fish and other aquatic life, including native bull trout, which depend on cold water.

The report says shrinking snowpack, increased glacial melt and more rain instead of snow will change when spring runoff occurs. It also projects drier summers overall, punctuated by heavier downpours.

McDowell said climate change is not the only pressure reshaping the landscape. As temperatures rise, wildlife will also have to contend with highways, rail lines, recreation and other human activities that can make it harder to adapt.

"It's important when we think about climate to understand that the issues that are driven by climate change ... are often moderated by or intersect with other processes of environmental change or social conditions on the ground," he said.

Many plants and animals will need to move to cooler habitats as temperatures rise. While the region's mountains provide opportunities to move upslope, northward or into cooler, shaded areas, McDowell said those movements will only be possible if habitat remains connected.

"We need to focus not only on what's happening in the high mountains, but also what's happening in those valleys such that animals can move through them," he said.

Wolverines, which rely on persistent snowpack for denning, could face shrinking habitat while also encountering increasing recreation pressure in the areas that remain suitable.

"We're going to most likely have less suitable habitat, more people winter recreating in smaller areas of suitable backcountry recreation habitat, which is obviously going to present challenges," said McDowell.

Those habitat changes are expected to extend well beyond individual species. Parks Canada identifies alpine meadows as among the park's most climate-sensitive ecosystems and warns rising temperatures, changing precipitation patterns and declining snowpack are expected to shrink these habitats through the upward movement of the treeline, shrub expansion and shifts in plant and animal distributions.

Rather than focusing only on reducing greenhouse gas emissions, McDowell said the report also highlights the need to prepare ecosystems and communities for changes already underway. That includes protecting large connected landscapes, maintaining wildlife corridors, restoring natural ecosystems and pursuing what he described as "nature-positive" adaptation strategies that benefit both people and wildlife.

McDowell said there is already enough evidence to begin taking meaningful action.

"All three of those opportunities for meaningful action that I outlined are things that we have more than enough information to start working on now," he said.