Melancolia, Alexis Rockman’s fifth show at Sperone Westwater, concerns a series of iceberg paintings on the first floor. On the second floor is a selection of slightly earlier work, concentrating on brilliantly detailed, surreal images of flora and fauna. Rockman has long been recognized for the attention he pays to nature, finding in it not only visual tropes of the most remarkable kind, but a cautionary tale emphasizing our ever-increasing vulnerability to damages brought about by climate change.