Global warming is a global health crisis of epidemic proportions. As glaciers melt, oceans and rivers rage and catastrophic weather events become more common, it is critical to do all we can to slow the progression of the contributors to this alarming trend. Carbon dioxide emissions have been identified as a major contributor to global warming. Thus, it is refreshing to read the work by Montano et al. in this issue which quantifies the carbon dioxide emissions associated with unwarranted variation in CT and MRI studies, a proxy for overuse of these diagnostic modalities [1].
