LAUSR

Mountains are hotspots of biodiversity and ecosystem services, but they are warming about twice as fast as the global average. Climate change may reduce alpine snow cover and increase vegetation productivity, as in the Arctic. Here, we demonstrate that 77% of the European Alps above the tree line experienced greening (productivity gain) and <1% browning (productivity loss) over the past four decades. Snow cover declined significantly during this time, but in <10% of the area. These trends were only weakly correlated: Greening predominated in warmer areas, driven by climatic changes during summer, while snow cover recession peaked at colder temperatures, driven by precipitation changes. Greening could increase carbon sequestration, but this is unlikely to outweigh negative implications, including reduced albedo and water availability, thawing permafrost, and habitat loss. Description Alpine snow loss and vegetation gain Mountains are experiencing more dramatic warming than lower elevations, with increasing snowmelt and changing patterns of snowfall. Rumpf et al. examined how the past four decades of climate change have influenced snow cover and vegetation productivity in the European Alps. Using remote sensing data, they found that snow cover declined significantly, but so far over less than 10% of the study region. Vegetation productivity has increased across over two-thirds of the area above tree line, with potential ecological and climate impacts. Feedbacks between snow and vegetation will likely lead to even more pronounced changes in the future. —BEL Satellite imaging confirms that climate change is causing declines in snow cover and increases in plant productivity across the European Alps.