PFAS chemicals are all around us. They're used in frying pans, food packaging and waterproof coats but they have been linked to thyroid disease, liver damage and cancer. The trouble is that PFAS just doesn't go away- these 'forever chemicals' build up in our bodies and the environment.

Tom Heap and Helen Czerski look back at the invention of these miracle chemicals, their use in the Second World War and the Space Race and meet Robert Bilott, the American lawyer who held the PFAS manufacturers to account, going head to head with the enormous DuPont corporation. They're also joined by Stephanie Metzger of the Royal Society of Chemistry, Hannah Evans from the environmental charity Fidra and by the journalist Leana Hosea of Watershed Investigations.

Producer: Alasdair Cross

Assistant Producer: Toby Field

Rare Earth is produced in association with the Open University

40 years ago a hole was discovered in the ozone layer. It provoked an international effort to ban the chemicals that were destroying our protection from the sun. Tom Heap and Helen Czerski are joined by Jonathan Shanklin, one of the team that realised that CFC chemicals used in aerosol cans and refrigerants were helping to create a 20 million square kilometre hole in the ozone layer above Antarctica. Also on the panel they speak to Alice Bell, author of ‘Our Biggest Experiment: a history of the climate crisis’ and head of policy, climate and health at Wellcome, and Bristol University's Professor Matt Rigby who helps monitor how well countries are sticking to their promises on protecting the ozone layer.

They discuss the unparalleled international unity that swiftly banned the worst of the ozone-destroying chemicals, and ask why we can't come up with a similar solution for manmade climate change. Tom will be meeting the detectives dedicated to hunting down the chemicals that still threaten the ozone layer and come with an enormous cost to the climate.

Featuring contributions from:

Jonathan Shanklin - Emeritus Fellow, British Antarctic Survey

Matthew Rigby - Professor of Atmospheric Chemistry, University of Bristol

Alice Bell - Head of Policy: Climate and Health, Wellcome

Producer: Beth Sagar-Fenton

Rare Earth is produced in collaboration with the Open University

The wolf has mounted an extraordinary comeback. Once hunted to extinction across Western Europe, the wolf has taken advantage of the collapse of the Iron Curtain and the depopulation of the countryside to spread from east to west, reaching the suburbs of Amsterdam and Brussels. Only Britain, Ireland, Malta, Cyprus and Iceland now lack the top predator that haunts our fairytales.

Tom Heap and Helen Czerski go face to snout with the wolf to find out the secrets of its success. They're joined by writer, Adam Weymouth, who tracked the route of a pioneering wolf called Slavc that made its way from Slovenia to Verona, kick-starting the return of the wolf packs to swathes of northern Italy. Erica Fudge of Strathclyde University shares her research into werewolf tales of the early modern period and BBC Central Europe correspondent Nick Thorpe digs into the relationship between farmers and wolves in their Carpathian heartland to reveal the conflicts we can expect as the western wolves increase their population.

Producer: Alasdair Cross

Assistant Producer: Toby Field

Rare Earth is produced in association with the Open University

Special thanks to Wolf Watch UK

For the Arctic, 2024 was the second-warmest year on record, with temperatures rising much faster than the global rate. The region's resources- oil, gas, iron ore, uranium, even diamonds and the rare earth metals used in electric cars- suddenly seem accessible. That's caught the attention of China, Russia and the US, with President Trump, eager to mount a hostile takeover bid for Greenland.

In the first of a new series of Rare Earth, physicist Helen Czerski and environment journalist, Tom Heap consider the impact of this sudden global interest on the people, wildlife and landscape of the far north.

It's not the first time that climate change has determined the fate of the region. For 500 years the Vikings occupied Greenland, using it as a base for their discovery of North America. By the late 14th century temperatures were falling, their crops failing and supply ships from Scandinavia struggling to make it through the expanding icepack. Communications faltered and then stopped completely. Historian, Eleanor Barraclough joins Tom and Helen to explore the fate of the last Norse Greenlanders- one of the great mediaeval mysteries and a warning of the power of a changing climate.

They're also joined by Duncan Depledge from Loughborough University and the Royal United Services Institute who fills them in on the military and political backdrop to the Arctic Goldrush. In 2007 Russian explorer, Artur Chilingarov led a submarine expedition to the North Pole where he planted a Russian flag on the seabed. It was a blatant land grab by the Putin regime and a warning of Russian expansionism to come. The other Arctic nations are responding, with Denmark ploughing cash into the defence of Greenland as the United States and China stake their own claims to the riches of the frozen north that isn't quite as frozen as it was.

The impact of climate change on the region's wildlife is so often encapsulated by the image of a polar bear on an ice floe, but ecologist Helen Wheeler of Anglia Ruskin University is more interested in the northward march of the beaver. These landscape engineers are actually moving ahead of the treeline, using rocks and mud to dam the rivers of the far north. The dams are blocking travel routes of Inuit hunters and fishers and may even be helping to raise the temperature of Arctic lakes.

Producer: Alasdair Cross

Assistant Producer: Toby Field

Rare Earth is produced in association with the Open University

Could 2025 be a year of progress on climate change and the nature crisis? Tom Heap and Helen Czerski search for some tentative green shoots with former Green MP Caroline Lucas, editor in chief of Business Green James Murray, and climate comedian Stuart Goldsmith.

Producer: Emma Campbell

Assistant Producer: Toby Field

Rare Earth is produced in association with the Open University

An ancient Babylonian text, Hammurabi’s Code of Laws, forbids the cutting down of street trees without permission. Nearly 4000 years later, threats to our urban trees still arouse the strongest passions. Coventry residents organised a record-breaking mass tree hug in November to save 26 trees marked for the chainsaws and the battle to save thousands of Sheffield's street trees from the council's contractors inspired folk songs and expensive legal battles.

As so many of us bring a tree home for Christmas, Tom Heap and Helen Czerski consider our feelings about street trees, the sweet hit of nature that provides year round shade and wildlife habitat in the least promising of city circumstances.

They're joined by Jon Stokes of the Tree Council, landscape historian Sonia Dümpelmann and Paul Powlesland, barrister and founder of Lawyers for Nature.

Producer: Alasdair Cross

Assistant Producers: Ellie Richold and Toby Field

Rare Earth is produced in association with the Open University

With fans travelling halfway across the country, stars expecting first class flights and venues serving up beefburgers and drinks in plastic cups the worlds of professional sport and live music share a pretty poor reputation for environmental impact. Add in the wasteful habits of high end film and TV productions and it starts to look as though anything that's fun has a disproportionate impact on the planet.

In Liverpool, they're hoping to change all that. The United Nations has asked the city to use its reputation as a hotbed of culture to devise ways to cut the carbon cost of live events and film production. To launch the project the city is hosting a conference and a series of high profile gigs with Massive Attack, Idles and Chic to showcase best practice and spread the word that fun doesn't need to cost the planet.

Helen Czerski and Tom Heap host a panel from the worlds of sports, entertainment and science to discuss a green future for fun, in front of an audience at Liverpool's Exhibition Centre.

Producer: Alasdair Cross

Assistant Producer: Toby Field

Rare Earth is produced in association with the Open University

It's been a hard year for the Amazon rainforest. The toughest drought on record has helped spread fires that have been the worst in two decades. That combination has hit the local people. “If these fires continue, we indigenous people will die,” says Raimundinha Rodrigues Da Sousa who runs the voluntary fire service for the Caititu indigenous community in the Brazilian Amazon. Her land is supposed to be protected but outsiders come in and set fires so that they can clear the land for agriculture.

For Rare Earth, Tom Heap and Helen Czerski take a look at the state of the Amazon rainforest, analyse its role in the global climate and consider the political battle over its future. They're joined by BBC South America correspondent, Ione Wells and by Angela Maldonado who has worked for 25 years in the Amazon, protecting night monkeys that are stolen and traded for medical research. Based on the Colombia-Peru-Brazil border, Angela has a unique perspective on the long-running war between development and conservation in the region.

Patricia Medici explains her work to conserve the extraordinary tapir, South America's largest land mammal and Niki Mardas reveals the latest results from Global Canopy's Forest 500 campaign which examines the involvement of 500 major companies in the supply chains which hasten the destruction of the Amazon rainforest.

Producer: Alasdair Cross

Assistant Producer: Ellie Richold

Rare Earth is produced in association with the Open University

Some of the wealthiest tech entrepreneurs share a vision of life beyond the horizon. They see a future for humankind that abandons our tired, dirty planet and creates new colonies of health and creativity on the Moon, on Mars or even further into deep space. Is this a wise precaution for all our futures or an insurance policy for the super-wealthy as they continue to trash our home planet? Tom Heap and Helen Czerski are joined by British astronaut, Tim Peake to consider the big moral questions of space colonisation and the practical problems of devising ways to make the best of the extraordinary possibilities of space without increasing the pressure on Earth’s resources. If we do colonise another planet how do we avoid making the same mistakes again? How do we grow food and find or produce freshwater? How can we travel to, from and around these planets without burning more fossil fuels? Could the answers help us all live a better life right here, right now? Joining Helen, Tom and Tim in studio are Eloise Marais, who leads the Atmospheric Composition and Air Quality research group at University College London and co-chair of the Environmental Task Force at Space Scotland, Andrew Fournet, and Tom pays a visit to a company in Bletchley who are developing nuclear fusion propulsion.

Producer: Alasdair Cross

Produced in association with the Open University

Our love affair with plastic has grown beyond all expectations since we were first introduced to the substance in the mid 20th century, and the rate at which we're using it shows no sign of slowing. But the tidal wave of plastic pollution we've unleashed is causing serious environmental problems. In this programme, Helen Czerski and Tom Heap hear how some of our plastic waste is burnt in incinerators or sent overseas, causing pollution far from our shores. In their search for solutions, they visit the Plastic Waste Innovation Hub at University College London, where Professor Mark Miodownik shows them how science is trying to keep up with the proliferation of plastic pollution. Back in the studio, they're joined by Professor Steve Fletcher from the University of Portsmouth, Sally Beken from Innovate UK, and environmental journalist Leana Hosea from Watershed Investigations, to talk about how we got here and how we can change our relationship with plastic. In the 2000s the amount of plastic waste generated rose more in a single decade than it had in the previous forty years. It's in everything - from our clothes, cars and cosmetics, to the 2.5 billion disposable drinks cups now discarded every year in the UK. It seems we can't live without it. So Helen and Tom ask: who's in charge now - us or plastic?

Producer: Emma Campbell

Produced in association with the Open University