title: Global carbon dioxide levels near worrisome milestone.
authors: Richard
authors: R
authors: Monastersky
mesh_terms: D001272:Atmosphere / Q000737:chemistry*; D002245:Carbon Dioxide / Q000032:analysis*; D057965:Carbon Sequestration; D062305:Geographic Mapping; D006254:Hawaii; D006802:Human Activities
chemical_list: D002245:Carbon Dioxide