Guardian: In Alaska, climate change is creating an unforeseen humanitarian crisis. Arctic sea ice – which had protected communities from coastal erosion and flooding – is rapidly disappearing and signalling a radical transformation of this northern ecosystem. Scientific observations during the summer of 2007 documented a new record low. In 2006, the US government completed a $2.5m (£1.7m) seawall to protect the native village of Kivalina, located on an island in the Chukchi Sea. But on the day …