Polar bears rely on ice for hunting and a longer ice-free season means reduced survival. Polar bears must spend longer on land waiting for the ice to freeze so that they can hunt, meaning a greater risk of starvation. Examples of starvation have been seen in recent years (see http://ow.ly/uWrlO) and are likely to continue as a result of on-going climate change.
The ice-free season across the Arctic is getting longer by five days per decade, according to new research from a team including Prof Julienne Stroeve (UCL Earth Sciences). New analysis of satellite data shows the Arctic Ocean absorbing ever more of the sun's energy in summer, leading to a later appearance of sea ice in the autumn. In some regions, autumn freeze-up is occurring up to 11 days per decade later than it used to.