Ice-free Northwest Passage

Here's an image that depresses me. (Source: http://nsidc.org/arcticseaicenews/ )

As the Arctic warms, less ice remains throughout the summer. This year, it appears that the Northwest Passage may be completely ice free by mid-September. The fewer months of ice cover, the more solar energy the Arctic Ocean will absorb and the more likely it is that subsequent summers will be even more ice-free. This is just one of the positive (amplifying) feedback loops that makes climate change a serious threat to ecosystems in many parts of the world.