A new study comparing past and present ocean temperatures reveals the global ocean has been warming for more than a century. Join Dean Roemmich, Scripps physical oceanographer and study co-author, as he describes how warm our oceans are getting, where all that heat is going, and how this knowledge will help scientists better understand the earth's climate. Learn how scientists measured ocean temperature during the historic voyage of the HMS Challenger (1872-76) and how today's network of ocean-probing robots is changing the way scientists study the seas. (#23999)