It is a great pleasure to give this, the first Revelle Commemorative Lecture, for [ had the privilege both to know Roger over the last decade of his career, and to work on problems in whicln he was keenly interested. Roger of course did not personally establish that carbon dioxide was increasing in the atmosphere; that was rec- ognized much earlier in the centurv (1). But his passion for this problem, and his leadership (2), his uncovering of what we now call the “Revelle Factor” for carbon dioxide buffering of the ocean, and his hiring of Dave Keeling at Scripps during the IGY vears to make the first wonderful series of atmospheric measurements, are surely the basis for the world wide interest today. Roger also wrote one of the first papers on gas hydrates in the oceans, and introduced me to the subject. These amazing compounds will make their appearance in the lecture I give today.