Canada's boreal forest is undergoing a remarkable transformation, expanding northward as the climate warms, according to groundbreaking satellite analysis spanning over three decades. This study, published in the journal Biogeosciences, reveals the world's largest terrestrial biome has not only grown in area but also shifted towards higher latitudes, marking a significant ecological shift. The research, which examined imagery from NASA's Landsat program between 1985 and 2020, found a 12% increase in boreal forest cover, equivalent to an expansion of approximately 0.844 million square kilometers. The average latitude of forest cover moved north by about 0.29 degrees, with the most significant gains occurring between 64 and 68 degrees north. Canada, home to the largest share of the global boreal forest, is witnessing the fastest warming of any forested region, with surface temperatures rising by 1.4 degrees Celsius over the past century. This expansion has profound implications for the global carbon cycle. Younger boreal forests, up to 36 years old, store between 1.1 and 5.9 petagrams of carbon. If allowed to mature, these stands could sequester billions of additional tonnes of carbon dioxide, acting as a growing carbon sink even as climate change reshapes the region. The researchers analyzed over 224,000 satellite scenes at 30-meter resolution to produce annual maps of tree cover across the boreal zone, creating one of the most detailed long-term records of forest change to date. The findings suggest climate-driven shifts are gradually transforming Canada's northern landscapes, while also highlighting the boreal forest's evolving role in absorbing greenhouse gases.
