Harrison Schmitt

This graph by Peter Gleick reveals the cherry pick used by Harrison Schmitt to claim that "Artic [sic] sea ice has returned to 1989 levels of coverage" and Heartland's Joseph Bast to claim "In fact, National Snow and Ice Data Center records show conclusively that in April 2009, Arctic sea ice extent had indeed returned to and surpassed 1989 levels." See more on this from John Cook at Skeptical Science.