This will be an article for the Science Learning website for use by New Zealand teachers and their students to understand measurement of greenhouse gases using greenhouse gases. There will be two activities to follow: (i) using and interpreting a eddy co-variance data set such as that displayed in the text and (ii) using bubbles to observe air currents and associated eddies. This article and subsequent activities have been reviewed by experts  in science and pedagogy to ensure it will meet the needs of teachers.  