Al Gore, Arnold Schwarzenegger, French President Nicolas Sarkozy, German Chancellor Angela Merkel, and lots of other bigwigs and heads of state are gathering at U.N. headquarters in New York on Monday for the most high-level climate summit ever, but one world leader will be noticeably absent: George W. Bush. The meeting is intended to build momentum for big U.N. climate talks to be held in Bali, Indonesia, in December. Bush is focused on a climate gathering of his very own, which will be held with 16 “major emitters” in Washington, D.C., on Thursday and Friday of this week. Watch Gristmill today for updates from the U.N. summit, and stay tuned for all the action later this week.