In this episode of the Physics World Weekly podcast, we talk about the pros and cons of injecting large amounts of aerosols into the atmosphere to offset global warming. Wake Smith of Yale University and Harvard University in the US explains how it could be done and emphasises that this solar geoengineering is not a solution to climate change but rather a “fire extinguisher” that could be used in an emergency.

Also on hand are Nicole Xu and Jason Geder of the US Naval Research Laboratory who explain how microscopic features found on the skin of sharks are inspiring the development of new hull materials for unpiloted underwater vehicles. They also chat about those controversial shark’s skin-inspired swimsuits that have been banned from competitions.

• You can read more about Smith’s latest research on solar geoengineering in “Higher-altitude solar geoengineering brings no cost benefit, study predicts”. His new book is called Pandora’s Toolbox.