The conversation about fluoride’s health benefits has exploded recently after a US federal toxicology report, court ruling and independent scientific review all called for updated risk-benefit analysis. Ian Sample hears from Catherine Carstairs, professor of history at the University of Guelph in Canada, about how attitudes to fluoridation have evolved, and Oliver Jones, professor of chemistry at RMIT University in Australia, about where the science stands today. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

Madeleine Finlay hears from the Guardian’s environment editor, Damian Carrington, about the controversial climate finance deal that brought Cop29 negotiations to a close in the early hours on Sunday morning in Baku, Azerbaijan. Developing countries asked rich countries to provide them with $1.3tn a year to help them decarbonise their economies and cope with the effects of the climate crisis. But the final deal set a pledge of just $300bn annually, with $1.3tn only a target. Damian tells Madeleine how negotiations unfolded, and what we can expect from next year’s conference in Brazil. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

Science editor Ian Sample joins host Madeleine Finlay to discuss some of the most intriguing science stories of the week. From a study finding that fat cells ‘remembering’ past obesity drives yo-yo dieting, to concerning developments in the bird flu virus, and research pinpointing which parts of the UK are best at spotting fake accents. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

It’s a dream for many children, but what does it actually take to become an astronaut? Science correspondent Hannah Devlin tells Ian Sample about her trip on a zero gravity flight with the European Space Agency (Esa). Back on solid ground she also got to speak to Rosemary Coogan, one of Esa’s newest recruits, about the rigorous process that led to her being chosen from more than 20,000 applicants, to become an astronaut, and what she hopes to achieve in her role. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

At a moment when the world feels like a particularly unsettling place, Science Weekly is asking what it is that makes humans happy – and how we can bring more happiness into our lives. In episode two, Ian Sample asks which happiness strategies are backed up by science. He hears from Elizabeth Dunn, a professor of psychology at the University of British Columbia, who recently scrutinised a whole lot of happiness research to work out which recommendations are most reliable. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

At a moment when the world feels like a particularly unsettling place, Science Weekly is asking what it is that makes humans happy – and how can we bring more happiness into our lives? In episode one, Ian Sample asks what makes a country happy? Johannes Eichstaedt, assistant professor of psychology and human-centred AI at Stanford University, explains why the Nordic countries often rank highly in the annual World Happiness Report, and what we can learn if we look beyond them. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

Madeleine Finlay talks to science editor and podcast co-host Ian Sample about how Donald Trump approached science when in office last time, and what his second term is likely to mean for the environment, health and scientific research. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

Space-settling enthusiasts have long had an eye on Mars, and now they have the backing of the world’s richest man. Elon Musk recently claimed that humans could be on the planet by 2030 and be living there in a self-sustaining city within 20 years. But is it really that simple? Madeleine Finlay heads to Imperial College London where Prof Sanjeev Gupta gives her a tour of the red planet, and meets Kelly Weinersmith who, along with her husband, Zach, recently won the Royal Society Trivedi science book prize for their book A City on Mars. She explains why life on Mars may not be the idyll some would have us believe. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

Biodiversity correspondent Phoebe Weston takes Madeleine Finlay through the news from the UN Cop16 biodiversity summit in Cali, Colombia. Countries are wrangling over funding to protect nature and who should profit from the natural resources of the world’s least developed nations. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

A startup company, Heliospect Genomics, is offering to help wealthy couples screen their embryos for IQ using controversial technology that raises questions about the ethics of genetic enhancement. Science correspondent Hannah Devlin tells Madeleine Finlay about the joint investigation into the company by the Guardian and the campaign group Hope Not Hate. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

With less than two weeks until the US election, Madeleine Finlay speaks to climate activist and author Bill McKibben to find out what a win for Donald Trump could mean for the environment and the world’s climate goals. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

Madeleine Finlay hears from Ted Schultz, curator of ants at the Smithsonian National Museum of Natural History, about his recent study into the origins of fungi farming in ants. He tells Madeleine about the incredibly complex way that ants cultivate and protect their fungi gardens, and how the asteroid that hit Earth 66 million years ago could have kickstarted it all. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

As the sleep tracking industry booms, some worry that it could be driving orthosomnia, the medical term for an unhealthy obsession with attaining perfect sleep, usually driven by a wearable device. Madeleine Finlay speaks to consultant neurologist and sleep physician Dr Guy Leschziner to find out whether this tech is helping or hindering our chances of maximising sleep’s health benefits. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

Ian Sample speaks to Bernadette Woods Placky, chief meteorologist at nonprofit Climate Central, about the 2024 Atlantic hurricane season so far, and what it tells us about how hurricanes will behave in future. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

With awards for the discovery of microRNA and the creation of new proteins, plus recognition for artificial intelligence via the physics and chemistry prizes, Madeleine Finlay hears from the Guardian science team – Nicola Davis, Ian Sample and Hannah Devlin – as they break down the news, science and surprises from this year’s Nobels. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

We’re used to hearing about the power of artificial intelligence to spread misinformation – but could it also be a tool for persuading people of the truth? Ian Sample speaks to Thomas Costello, an assistant professor of psychology at American University, who has published a study exploring the potential for AI chatbots to lead people away from conspiracy beliefs. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

Madeleine Finlay is joined by Ian Sample, the Guardian’s science editor and Science Weekly co-host, to answer the questions we are all asking about Covid this autumn, from what is going on with the new variant XEC to how to get a vaccine and what scientists think the government should be doing differently. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

Just before Britain’s last coal-fired power station, Ratcliffe-on-Soar, powered down for the final time, Madeleine Finlay travelled to Nottinghamshire with energy correspondent Jillian Ambrose for a last tour of the site. Britain is the first major economy to move away from coal entirely as it strives to meet the target of net zero by 2030. Jillian and Madeleine speak to employees to find out what working at the plant has meant to them, and how they’re feeling as the closing date approaches. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

Industrial civilisation is close to breaching a seventh planetary boundary, and may already have crossed it, according to scientists who have compiled the latest report on the state of the world’s life-support systems. They say ocean acidification is close to critical threshold, posing a threat to marine ecosystems and global liveability. Ian Sample speaks to Prof Helen Findlay, a biological oceanographer at the Plymouth Marine Laboratory, to find out why the oceans have reached this state, and whether there is anything we can do to reverse the damage.. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>

Madeleine Finlay speaks to Dr Saul Newman, an interdisciplinary researcher at University College London and the University of Oxford, who has just won an Ig Nobel prize – given to scientific research that ‘first makes people laugh, and then makes them think’ – for his work showing that many claims of people living extraordinarily long lives come from places with short lifespans, no birth certificates, and where clerical errors and pension fraud abound. He tells Madeleine what happened when he went looking for the world’s centenarians, and how his work has been received by the longevity research community. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>