There never really needs to be an excuse to look at incredible images of polar bears in the wild, but today has been designated International Polar Bear Day by conservation group Polar Bear International . So to mark the occasion, here's a selection of shots from the Greenpeace archives. Of course, polar bears - along with many other Arctic species - are at risk, thanks to climate change, as many of these photographs show. As the sea ice shrinks each year, polar bears lose their hunting grounds while oil companies like Shell see an opportunity to move in and search for more oil. So if you like the photos, make sure you email Shell and demand an end to its plans for Arctic drilling .