title: Environmental optimist.
authors.forename: Ralph
authors.initials: R
authors.lastname: Costa
mesh_terms: D003247:Conservation of Natural Resources / Q000639:trends*; D004787:Environmental Pollution / Q000517:prevention & control*; D033161:Government Regulation; D017752:Greenhouse Effect; D007391:International Cooperation; D011640:Public Policy; D014481:United States