Many forests are losing their winter snowpack as global temperatures rise, and that could substantially slow their growth – and reduce the amount of carbon they remove from the atmosphere. Current projections “are not incorporating that complexity of winter climate change, so they are likely overestimating what the future carbon storage will be”, says Emerson Conrad-Rooney at Boston University in Massachusetts. Warming temperatures are generally expected to boost growth in temperate forests, mainly by spurring decomposition and making more nutrients available during the warm growing season. However, models largely don’t account for changes during winter – especially the loss of snow. “The loss of deep, insulating snowpack cannot be understated,” says Elizabeth Burakowsi at the University of New Hampshire. Her research has shown deep snow days will disappear across most of the US by the end of the century, with consequences for water storage and ecosystem health.

• Original report from National Academy of Sciences: Declining winter snowpack offsets carbon storage enhancement from growing season warming in northern temperate forest ecosystems