As explained above, sea ice reflects much of the sun's radiation back into space, whereas dark, ice - free ocean water absorbs more of the sun's energy. (nsidc.org)
Another positive feedback of global warming is the albedo effect: less white summer ice means more dark open water, which absorbs more heat from the sun. (newscientist.com)
If you can't really avoid hitting something, then choose an object that is capable of absorbing more energy. (wannadrive.com)