Standing on a rocky outcrop in British Columbia’s Great Bear Rainforest last autumn, I watched as a spirit bear – a rare white-furred black bear – foraged for salmon in the crystal-clear river below. Local Gitga’at First Nation guide Marven Robinson explained how these genetically unique bears exist nowhere else on Earth, their population hovering around 400 individuals. “Climate change is altering salmon runs these bears depend on,” he told me. “When the salmon cycles change, everything here changes.”
This delicate balance between species and their environments is unraveling globally at an unprecedented rate. A troubling new study published in the journal Biological Conservation reveals that more than 3,500 animal species are now facing severe threats from climate change – double the number identified just four years ago.
The research, led by scientists from the International Union for Conservation of Nature (IUCN), examined 150,000 species and found that mammals, amphibians, and birds face particularly dire circumstances as temperature and precipitation patterns shift faster than many species can adapt.
“We’re witnessing ecological communities being pulled apart thread by thread,” explains Dr. Wendy Foden, chair of the IUCN’s Climate Change Specialist Group. “Many species have co-evolved over millions of years, developing precise relationships with specific plants, pollinators, or predators. When climate disrupts these relationships, entire ecosystems can collapse.”
Here in Canada, the consequences are already visible across diverse landscapes. The woodland caribou, culturally significant to many Indigenous communities and an iconic Canadian species, is struggling with climate-induced habitat changes. Warming temperatures have altered the timing of plant growth, creating mismatches between when caribou migrate and when nutritious vegetation is available for calving season.
Salmon Nation, a coalition of Indigenous-led conservation groups working along the Pacific Coast, has documented how warming rivers and changing ocean conditions are disrupting Pacific salmon runs that have sustained coastal ecosystems and communities for millennia. Water temperatures above 18°C create thermal stress for salmon, and in recent summers, some BC rivers have reached lethal temperatures above 20°C.
“This isn’t just about losing individual species,” says William Housty, conservation manager for the Heiltsuk Integrated Resource Management Department in Bella Bella, BC. “When salmon decline, it affects everything – from the nutrients in our forests to our food security to our ceremonial practices. Our people have managed these relationships for thousands of years, but climate change is happening too quickly.”
The biodiversity crisis extends beyond charismatic mammals. Dr. Karen Kidd, an ecotoxicologist at McMaster University who studies freshwater ecosystems, showed me samples of aquatic invertebrates collected from streams across southern Ontario last spring. Many species that were once abundant have declined or disappeared entirely.
“These tiny creatures form the base of food webs,” Kidd explains. “They process leaf litter, filter water, and feed larger animals. When we lose this microscopic biodiversity, the effects ripple upward through the entire ecosystem.”
The new research highlights how interconnected threats amplify risks to species. Climate change compounds existing pressures from habitat loss, pollution, and invasive species. Many animals and plants face what ecologists call “extinction debt” – where populations might appear stable but have already crossed thresholds that make their long-term survival impossible without intervention.
The Global Biodiversity Framework, adopted by nearly 200 countries at the UN Biodiversity Conference in Montreal in 2022, commits to protecting 30% of land and water by 2030. But protected areas alone won’t be enough if climate change renders these habitats unsuitable for the species they were designed to protect.
“We need climate-smart conservation,” says James Snider, vice president of science, research and innovation at World Wildlife Fund Canada. “This means creating connected habitats that allow species to move and adapt, restoring ecosystems that naturally store carbon, and working with Indigenous communities who have managed biodiversity sustainably for generations.”
There are glimpses of hope amid the sobering statistics. When I visited the Koeye River Conservancy on BC’s central coast earlier this year, I witnessed firsthand how the Heiltsuk Nation is combining traditional knowledge with contemporary science to monitor environmental changes and protect crucial habitat. Similar Indigenous-led conservation initiatives are emerging across Canada, from the boreal forests of Quebec to the grasslands of Saskatchewan.
Community-based monitoring programs are engaging citizen scientists to track phonological changes – the timing of natural events like bird migrations, plant flowering, and insect emergence. This growing dataset helps researchers understand how climate is reshaping ecological relationships in real time.
Urban initiatives are also playing a crucial role. The Butterflyway Project, led by the David Suzuki Foundation, has created networks of native plant gardens in cities across Canada, providing crucial habitat for pollinators struggling with climate-induced timing mismatches between their life cycles and flowering plants.
As the biodiversity crisis accelerates, the solutions require both urgency and precision. Conservation strategies must consider not just where species live today, but where they might need to move as climate changes. This means protecting existing habitat, restoring degraded areas, and maintaining connectivity between protected spaces.
“We need to address both the climate and biodiversity crises together,” explains Dr. Kai Chan, professor at the University of British Columbia’s Institute for Resources, Environment and Sustainability. “Healthy ecosystems sequester carbon and buffer against climate impacts, while climate stabilization is essential for biodiversity conservation.”
As I left the Great Bear Rainforest, watching the spirit bear disappear into the ancient cedars, I carried both a sense of wonder and responsibility. These interconnected ecological communities have evolved over millennia. Now their future depends on how quickly humanity can respond to the accelerating biodiversity crisis unfolding in real time across landscapes both wild and managed.
The stakes couldn’t be higher – not just for the 3,500 species now recognized as climate-threatened, but for the countless others whose fates are intertwined with them, including our own.
