Peaknik: A person who believes that the world's oil reserves will soon peak and that subsequent shortages will devastate civilization. (Word Spy.)
Although peaknik originated with the concept of peak oil, its meaning has lately become more inclusive. In "The Dystopians," published in the Jan. 26, 2009, issue of the New Yorker (registration required), Ben McGrath provides a short list of peaknik theories:
Peaknik's most obvious antecedent is peacenik, a semi-contemptuous term for a pacifist that dates back to the 1960s or earlier. The -nik suffix comes from a Russian word part meaning "to pertain to or be involved in"; it was familiar to non-Russian speakers from Sputnik, the Soviet satellite launched in October 1957. (And to speakers of Yiddish and Yinglish from nudnik, "a pest," and nogoodnik, "a worthless person.") Six months after Sputnik ushered in the era of space exploration, San Francisco Chronicle columnist Herb Caen coined beatnik to describe a member of the Beat generation.
Mark Liberman, writing in Language Log last October, discussed the linguistic construct "Peak X", taking as his jumping-off point the recent coinage "peak wingnut."
According to Word Spy, in the early 1990s a "Peaknik" was a fan of the David Lynch television series "Twin Peaks."
UPDATE for Bay Area readers: Peaknik Dmitry Orlov, who features prominently in Ben McGrath's New Yorker article, will be speaking at San Francisco's Fort Mason Friday, Feb. 13, at 7:30 p.m. The talk is sponsored by the Long Now Foundation; admission is free, but events tend to sell out. To guarantee a seat, buy a $10 ticket.