A Scottish tea mystery: the list – episode two

As global leaders and environmental activists descend on Brazil for next week’s Cop30 climate summit, Madeleine Finlay speaks to the Guardian’s global environment editor, Jon Watts, who recently sat down for an exclusive interview with the UN secretary general, António Guterres. As he approaches his final summit as the UN chief, Guterres reflected on humanity’s progress in attempting to limit global warming to 1.5C above pre-industrial levels, why Indigenous voices must be listened to and how he remains positive in the face of the climate crisis. Help support our independent journalism at theguardian.com/sciencepod

Science correspondent Nicola Davis investigates the strange story of Tam O’Braan and his attempts to grow tea in Scotland. In episode three, all of Tam’s lies come to a head and Stuart uncovers exactly where Tam was sourcing tea to supply to hotels and shops. At trial, Tam takes the stand and Richard and the Scottish growers finally get some answers. But what remains today of the nascent Scottish tea industry that Tam instigated?. Help support our independent journalism at theguardian.com/sciencepod

Science correspondent Nicola Davis investigates the strange story of Tam O’Braan and his attempts to grow tea in Scotland. In episode two, Nicola hears how Tam’s network of Scottish tea growers began to have suspicions about exactly what he was selling and where it came from, and how cutting edge science helped provide some answers. Help support our independent journalism at theguardian.com/sciencepod

Science correspondent Nicola Davis investigates the strange story of Tam O’Braan and his attempts to grow tea in Scotland. In episode one, Nicola looks back on her first meeting with Tam while working on a feature about tea plantations in the UK. He was selling his award-winning Scottish-grown tea to some of the UK’s finest hotels, but something didn’t quite add up. And Nicola wasn’t the only person taking an interest in his story. Help support our independent journalism at theguardian.com/sciencepod

An electronic eye implant half the thickness of a human hair has helped people with incurable sight loss to see again, opening up a potential ‘new era’ in tackling blindness. Madeleine Finlay hears from Mahi Muqit, a surgeon from Moorfields eye hospital in London, about what this implant has meant for his patients and what the future could hold for vision-loss therapies. Help support our independent journalism at theguardian.com/sciencepod

As biodiversity declines, locating and conserving the planet’s plant life is becoming more important. The Millennium seed bank in Wakehurst, West Sussex, has been doing just that for 25 years, collecting and storing seeds and keeping them in trust for countries all over the world should they ever be needed. To mark the anniversary, Patrick Greenfield took a tour of the site. He tells Madeleine Finlay about the journey a seed takes from arrival to cold storage, and how some are already helping to return endangered plant species to the wild. Help support our independent journalism at theguardian.com/sciencepod

Celebrities including Bella Hadid, Justin Bieber and Miranda Hart have talked about their years-long struggles with the effects of Lyme disease, but despite rising rates and better awareness, the illness remains poorly understood. To understand more about how the illness can impact people over the long term, Madeleine Finlay hears from the Guardian’s Patrick Barkham about his daughter Milly’s experience, and from Prof John Aucott, director of the Johns Hopkins Lyme Disease Research Center, and associate professor of medicine at Johns Hopkins University. Help support our independent journalism at theguardian.com/sciencepod

The Traitors has returned to UK screens with its biggest viewing figures ever as 19 celebrities compete to be crowned the winner. The game depends on being able to accurately spot a liar, but are any deception detection methods actually backed up by science? Madeleine Finlay speaks to Timothy Luke, a senior lecturer in the department of applied psychology at the University of Gothenburg, to find out whether sweating, nervous ticks and reduced eye contact really can alert us to deception, and if not, what can?. Help support our independent journalism at theguardian.com/sciencepod

This year’s Nobel prizes in chemistry, physics and physiology or medicine have celebrated work that paves the way for the next generation of quantum technology, the creation of porous materials that have been compared to Hermione Granger’s handbag and the discovery of the hidden army inside us that helps to keep our immune system in check. To find out more, Madeleine Finlay talks to our science editor, Ian Sample, and correspondents Nicola Davis and Hannah Devlin. Help support our independent journalism at theguardian.com/sciencepod

Kevin Hall spent 21 years at the US National Institutes of Health and became known globally for his pioneering work on ultra-processed foods. In April he unexpectedly took early retirement, citing censorship under the Trump administration. Now he has co-authored a book with the journalist Julia Belluz that aims to bust myths and challenge wellness orthodoxy on everything from weight loss and metabolism to supplements and wearables. Hall tells Ian Sample what he wants us all to understand about diet, exercise and weight loss, and what led to his departure from the job he loved. Help support our independent journalism at theguardian.com/sciencepod