Adam Rutherford talks to researchers on a major global study that aimed to quantify how climate change has already damaged the health of millions of people. Hugh Montgomery is the co-chair of the Lancet Countdown report and says that climate change is the largest single threat to global health. Climate scientist Peter Cox talks about his stark findings on the increase in the number of vulnerable people exposed to heat waves between now and the turn of the century.

We hear anecdotes and concerns from listeners following our item last week on the catastrophic decline in flying insects in the last quarter century and the disappearance of moth snow storms.

What can the social lives and brains of whales and dolphins tell us about the evolution of our species cognitive capacities and white matter? Adam talks to Susanne Shultz of the University of Manchester.

Everyone's favourite indoor firework, the Pharoah's Serpent, is under scientific scrutiny from chemists Tom Miller and Andrea Sella at University College London.