Certainty is comforting. Certainty is quick. But science is uncertain. And this is particularly true for people who are trying to understand climate change.Climate scientist, Tamsin Edwards tackles this uncertainty head on. She quantifies the uncertainty inherent in all climate change predictions to try and understand which of many possible storylines about the future of our planet are most likely to come true. How likely is it that the ice cliffs in Antarctica will collapse into the sea causing a terrifying amount of sea level rise? Even the best supercomputers in the world aren’t fast enough to do all the calculations we need to understand what might be going on, so Tamsin uses statistical tools to fill in the gaps. She joined the International Panel on Climate Change (IPCC) in 2018 and is currently working on the 6th Assessment Report which will inform the 2021 United Nations Climate Change Conference, COP26. She tells Jim Al-Khalili about her life and work and why she wishes more people would have the humility (and confidence) to consider the possibility that they might be wrong.Producer: Anna Buckley

As the craze for cold water swimming continues, Jim Al Khalili talks to triathlete and Professor of Extreme Physiology, Mike Tipton. Is it as good for our mental and physical health as many enthusiasts claim? And do the benefits go beyond a rush of adrenaline causing feel good endorphins to be released in our brains?Mike studies why people drown. He wants to understand the precise physiological changes that occur when we expose ourselves to extreme environments and to use that information to help save lives. (Shivering and sweating will only get you so far when it comes to temperature control). Most deaths at sea are caused by the initial cold water shock response, not hypothermia. People gasp for air and swallow lethal quantities of water. So is it a case of kill or cure for cold water swimmers? What does the scientific evidence say about the idea that repeated cold water immersion can boost our immunity and have an anti-inflammatory effect? Mike tells Jim how he came to specialise in this area of science and why he believes we should all be challenging our bodies more. Producer: Anna Buckley

When does a crowd of people become unsafe? How well will Aston Villa do next season? When is it cost-effective to replace a kitchen?The answers may seem arbitrary but, to Nira Chamberlain, they lie in mathematics. You can use maths to model virtually anything.Dr Nira Chamberlain is President of the Institute of Mathematics and its Applications, and Principal Mathematical Modeller for the multinational engineering company SNC-Lavalin Atkins.He specialises in complex engineering and industrial problems, creating mathematical models to describe a particular feature or process, and then running simulations to better understand it, and predict its behaviour.Nira is one of just a handful of esteemed mathematicians, and the first black mathematician. to be featured in ‘Who’s Who’, Britain’s book of prominent people.Since 2018, he’s made the Black Power List, which celebrates the UK’s top 100 most influential people of African or African-Caribbean heritage, ranking higher than Stormzy and Lewis Hamilton when he was first listed. Proof, he says, that maths really is for everyone.PRODUCER: Beth Eastwood

Luminescent bone-eating worms, giant squid and a sea cucumber commonly known as the headless chicken monster: some extraordinary creatures live at the bottom of the sea. For a long time almost everyone agreed the pressure was too intense for any life to exist. Now, it seems, the more we look the more new species we find. But, many fear, marine life would be threatened if plans to extract precious metals from the potato-sized metallic nodules that grow on the seabed are allowed to go ahead. Metals such as copper, manganese and cobalt are in high demand in the manufacture of mobile phones and renewable energy technologies, such as batteries for electric cars, wind turbines and solar panels. Deep sea mining companies argue that we will need these metals to create a carbon Net Zero economy. Meantime, the World Wildlife Fund is pushing for a moratorium on deep sea mining. And several companies agree: including Google, BMW, Volvo and Samsung. Do we need to choose between green and blue? Or is there a third way that protects both the planet and all the riches in our oceans?Marine biologist, Helen Scales talks to Jim Al-Khalili about her life and work: fish watching off an atoll in the South China Sea to assess the extinction risks to the Humphead Wrasse and a research expedition to explore the brilliant abyss. And she warns of the environmental devastation that could be caused if plans to mine the metals on the bottom of the ocean were to be allowed to go ahead. Producer: Anna Buckley

Neurological expert Peter Goadsby discusses the symptoms and prevalence of migraines, his breakthrough research on migraine causes, and new treatments that can prevent migraines. He explores the role of the trigeminal nerve, the discovery of a neuropeptide called CGRP, and the use of monoclonal antibodies and G-Pants in treating migraines. Goadsby reflects on his childhood curiosity and the intersection of medicine and research.

Professor Jane Clarke has had a fascinating double career. Having been a science teacher for many years, she didn’t start her research career until she was 40. Today she is a world-leading expert in molecular biophysics and, in particular, in how protein molecules in the body fold up into elaborate 3D structures, that only then enables them to carry out their roles. How they do this has been one of the fundamental questions in biology and the key to combating some of our most challenging diseases, caused by the misfolding of proteins.Jane talks about her journey, from Tottenham schoolteacher to Cambridge Professor and Fellow of the Royal Society, and how, despite the obstacles she’s encountered along the way, she’s always been driven by her passion to understand the mystery of the machinery of life.Producer: Adrian Washbourne

When Martin Sweeting was a student, he thought it would be fun to try to build a satellite using electronic components found in some of the earliest personal computers. An amateur radio ham and space enthusiast, he wanted to create a communications satellite that could be used to talk to people on the other side of the world. It was a team effort, he insists, with friends and family pitching in and a lot of the work being done on his kitchen table. Somehow he managed to persuade Nasa to let his microsatellite hitch a ride into space and, after the first message was received, spent more than a decade trying to get a good picture of planet earth. The technology that Martin pioneered underpins modern life with thousands of reprogrammable microsatellites now in orbit around the earth and thousands more due to launch in the next few years to bring internet connections to remote parts of the world. The university spin-off company, Surrey Satellite Technologies Limited (SSTL) that Martin set up in the 1980s with an initial investment of £100 sold for £50 million a quarter of a century later. If his company had been bought by venture capitalists, he says he would probably have ended up making TVs. Instead he developed the satellite technology on which so much of modern life depends. Producer: Anna BuckleyPhoto Credit: SSTL

We all know how to be more healthy. And yet we are also remarkably good at NOT doing what we know is good for us. We keep meaning to get fit, but the sofa seems so much more appealing than a run. We know we shouldn’t have another slice of cake, but we do. Behavioural psychologist, Professor Dame Theresa Marteau wants to understand why, despite the best of intentions, so many of us fail to adopt healthier lifestyles. She talks to Jim Al-Khalili about her life and work and why, after studying the evidence she changed her mind about how to change our behaviour. Back in the 90s, it seemed reasonable to assume that telling people they were at high risk of dying would jolt them into eating more healthily and taking more exercise. Now we know better. Thanks in large part to research pioneered by Theresa, we have a much more sophisticated understanding of what drives our behaviour. It turns out that small scale interventions to redesign our environment can exert a big influence on our behaviour by nudging us all into make better decisions, in ways that are beyond our awareness. Spoiler alert - smaller wine glasses really do make you drink less! Responses to Covid-19 show that nations can act rapidly and radically in response to immediate threats to health, even at huge cost. Can we do the same to tackle other threats to global health? Producer: Anna Buckley

Inside the mind of a forensic botanist, Mark Spencer tells Jim Al-Khalili how he uses plant evidence to help solve crimes. By studying the vegetation at crime scenes, Mark can tell how long a dead body has been laying in the ground. Brambles can be particularly informative, he says. And by looking at tiny traces of plants under the microscope, he can link suspects to victims, or particular locations. Mark tells Jim Al-Khalili how he came to be a forensic botanist. After working in bars and clubs in Soho for many years, he decided to study for a degree in botany and developed a special interest in water moulds. As a curator of the botanical collections at the Natural History Museum in London, he became intimately acquainted with British flora past and present. And, more recently, has spent a lot of time monitoring urban wildlife – recording how the composition of native species and non-native species in the capital is changing, as the global climate changes and the global trade in plants continues. Producer: Anna Buckley

What would happen to our carbon emissions if we all went vegan? Astrophysicist, Sarah Bridle tells Jim Al-Khalili why she switched her attention from galaxies to food. A rising star in the study of extra-galactic astronomy, Sarah was a driving force behind one of the most ambitious astronomy projects of recent times, the Dark Energy Survey of the universe. A few years ago, she started trying to calculate the carbon emissions from different foods so that she could make more informed choices about what she was eating in terms of the impact they were having on climate change. Before long, she was adapting the statistical tools and techniques she had developed to study dark matter and dark energy, to quantify the carbon cost of different foods and lobby government to make food labels indicating carbon cost of foods compulsory. Producer: Anna Buckley