Bornholm – a Danish island in the Baltic Sea – is trying to go carbon neutral by 2025. It’s a lofty ambition that would put the island decades ahead of most countries. This dream has been 15 years in the making; a crash in fish stocks meant Bornholmers had to reinvent themselves and they chose to become ‘the bright green island’. Since then, they’ve been making biogas from pig manure, building wind turbine after wind turbine, and now they're piloting new ways of storing this renewable energy, including in a battery made of salt. The island isn’t just trying to rid itself of fossil fuels – it's also aiming to go zero waste by 2032. In this week’s episode, Graihagh Jackson teams up with CrowdScience presenter Caroline Steel to explore Bornholm’s double quest to go green.The changes haven't just been at top-level – the island’s businesses and 40,000 residents have been encouraged to reduce their climate impact too. Graihagh visits a brewery whose production has gone carbon neutral by capturing CO2 to create the bubbles in its beers, and meets a chef whose Michelin-star restaurant uses locally-sourced food. And over on CrowdScience, Caroline tackles Bornholm’s zero waste ambition, visiting a project turning used nappies into compost and a glassblower making tableware out of wasted insulin vials. (https://www.bbc.co.uk/programmes/w3ct4y4h) Will Bornholm make its bold goals, and what lessons can be learned for elsewhere? Presenters: Graihagh Jackson and Caroline Steel Producer: Sophie Eastaugh Production Coordinators: Debbie Richford and Sophie Hill Series Producer: Simon Watts Editor: China Collins Sound Engineer: Tom Brignell