Study reveals hidden role of permafrost in ancient climate change The Brighter Side of News Kobuk Delta in Alaska (IMAGE) EurekAlert! Warming unlocks ancient carbon in Tibetan permafrost, triggering climate tipping point Phys.org When frozen ground starts to thaw, carbon takes a new route – a model shows why spring is the danger window Earth.com Arctic river deltas at risk from mounting pressures EurekAlert!