Sometimes a picture really is worth a thousand words, particularly when the picture is used to illustrate science. Technology is giving us better pictures every day, and one of them is helping a NASA-funded scientist and her team to explain the behavior of a greenhouse gas. Google Earth — the digital globe on which computer users can fly around the planet and zoom in on key features — is attracting attention in scientific communities and aiding public communication about carbon dioxide. Recently Google held a contest to present scientific results using KML, a data format used by Google Earth.