How propane might prevent air conditioning and refrigeration becoming an even bigger burden as our planet warms. Also, covid antiviral pills, and how we forgot to breathe properly. The Montreal Protocol is famous for reducing CFC emissions to help protect the Ozone Layer. We only started using things like CFCs as refrigerants in our fridges and air-conditioning because they weren't as flammable as many alternatives. They were mainly replaced by HFCs, though these are also on the way out. The reason? Their huge greenhouse warming potential (or GWP). Propane has long been thought to be an alternative because of its comparatively tiny GPW, but the safety standards haven't been in place in much of the world for many of the types of application that would make the big difference. Sophie Geoghegan, Climate Campaigner at the Environmental Investigation Agency, and Asbjørn Vonsild who has been working on some of the new standards, due to become normal in Europe next year tell Gaia what greenhouse savings there are to be made, both in terms of efficiency and the contents of the systems themselves. If public opinion and consumer choice can drive the transition as our cities heat up. This week two new Anti-viral pills that are designed to fight SARS CoV2 infections have made headlines in the UK. Professor Penny Ward is Chair of the Faculty of Pharmaceutical Medicine’s Policy Expert Group, and explains how they work, how they were developed, and when they will be properly available. And in the penultimate of our 2021 Royal Society Insight Investment Science Book Prize shortlisted authors, science journalist James Nestor describes his book, Breath: The new science of a lost art. The book documents James’s journey around the world investigating traditional eastern practices, the latest pulmonology research, and learning from the palaeontology of ancient skulls, and he attempts to cure himself with better breathing habits. Presented by Gaia Vince Produced by Alex Mansfield Made in association with The Open University