Michael Wilks immediate past President Standing Committee of European Doctors, and Pendo Maro, Senior Climate and Energy Advisor, Health and Environment Alliance and Health Care Without Harm, talk about how investment in reducing greenhouse gases produces immediate and lasting benefits to health. Such health benefits save money: moving the EU greenhouse gas emissions reduction target from 20% to 30% domestically by 2020 (compared to 1990 levels) would cost €46 billion per year in 2020 but save up to €30.5 billion annually through reduced medical bills or ill-health avoided, in addition to the up to €52 billion health gains associated with the current 20% target. The public health benefits can be used as a unifying argument to push towards an ambitious climate change outcome here in Cancun.