Category: Retired

Concrete blocks are the foundations of the modern world but they could be greener. Tom Heap meets Colin Hills and his team turning waste dust and carbon dioxide into building materials.

Professor Hills of the University of Greenwich has developed a technique that mimics natural processes, using carbon dioxide as a glue to form stone aggregates from waste dust left behind by heavy industry. The spin-off company, Carbon 8 Systems, has compressed the process into a shipping container and now makes building materials in the UK and France with this clever carbon-munching technique. Colin's colleague, Nimisha Tripathi wants to adapt the system for the developing world, choosing waste from her native India- things like pistachio shells and banana skin- to make a tailored range of building products relevant to the region in which they're made.

Tamsin Edwards of King's College London joins Tom to consider just how much carbon dioxide we can remove from the atmosphere by developing this new generation of bricks and mortar. Producer: Alasdair Cross Series Researcher: Sarah Goodman

Produced in association with the Royal Geographical Society. Special thanks for this episode to Professor Paul Fennell and Dr Rupert Myers of Imperial College London and to Professor Karen Scrivener of École Polytechnique Fédérale de Lausanne.

How to improve mass catering for the planet. Tom Heap considers how changing the menus in schools, hospitals and the armed forces could help in the fight against climate change.

Andy Jones, chair of the Public Sector Catering 100 Group, explains how his own farming family background informs his drive to reduce the amount of meat served in canteens and increase the choice of vegan and vegetarian options. Tom visits hospitals in Nottingham to see the drive in action and joins climate scientist, Dr Tamsin Edwards to consider the carbon impact of a broader shift from beef to beans.

Producer: Anne-Marie Bullock Researcher: Sarah Goodman

Produced in association with the Royal Geographical Society. Special thanks for this episode to Dr Rosie Robison from Anglia Ruskin University and to Dr Tara Garnett and Dr Peter Scarborough from the University of Oxford.

From clothes to cars and buildings, all our new 'stuff' takes energy and resources to produce. If we want to cut down the use of high carbon materials like steel and cement then we need a new attitude. We need to think about sharing more and valuing what we have, we need products that are designed to last longer.

Tom Heap meets Aisling Byrne from clothing app NUW. Concerned about the impact of fast-fashion on the environment, she found that lecturing friends who loved fashion didn't change their minds or behaviour, so she's designed a clothes-sharing app for people to put unwanted clothes into new hands and get the excitement of something 'new' in return. It can stop the demand for brand new products at the top end and avoid landfill at the other end. Professor Julian Allwood of Cambridge University expands on how much our desire for bigger and better is impacting on resources and how behaviour change needs to come sooner rather than later.

Producer: Anne-Marie Bullock Researcher: Sarah Goodman

Produced in association with the Royal Geographical Society. Special thanks for this episode to Dr Mike Tennant of Imperial College London, Dr Sonali Diddi of Colorado State University, Professor Jana Hawley of the University of North Texas and Professor Sandy Black of the London College of Fashion.

A big weight and a very, very deep hole. The team behind Gravitricity think they have found a solution to a serious problem with renewable energy. As we rely increasingly on wind and solar energy the risk rises of the lights going out when the wind doesn't blow and the sun doesn't shine. We can solve the problem with energy storage but batteries are expensive and don't last very long. As Tom Heap and Tamsin Edwards hear, the answer could lie with a deceptively simple pulley system. Put an enormous weight at the bottom of a mineshaft. When you have lots of wind or sun, use the electricity to pull the weight to the surface. When you're short of power, release it and send a huge surge of energy back into the grid.

Producer: Alasdair Cross Researcher: Sarah Goodman

Produced in association with the Royal Geographical Society. Special thanks for this episode to Professor Stephen Peake from the Open University and Dr Hugh Hunt from the University of Cambridge.

Heating our homes can be expensive and draughty old housing stock leaches carbon dioxide. But making homes more energy efficient can be a costly upheaval and is therefore often done piecemeal. Tom Heap meets the team from Energiesprong who are proposing a new model - retrofitting modern technology like insulating 'wraps' around the house, replacing roof tiles with solar panels and fitting ground source heat pumps into old housing stock. It's done on scale and on a whole-house basis to keep costs down with the aim of creating net zero energy homes but also to create 'kerb appeal' so that neighbours will want to 'keep up with the Joneses'. Tom is joined by climate scientist Tamsin Edwards to discuss whether tackling inefficient, poorly insulated housing head-on can provide great gains for people and planet.

Producer: Anne-Marie Bullock Researcher: Sarah Goodman

Made in association with the Royal Geographical Society. Special thanks for this episode to Kate De Selincourt, Professor Stephen Peake from the Open University, Professor Gavin Killip from the University of Oxford and John Palmer from Passivhaus Trust.

Soil is brilliant at capturing carbon dioxide and keeping it out of the atmosphere. But what if we could make it do an even better job? On a farm overlooking the broad River Tay in Perthshire they've sprinkled the fields with the waste product from quarrying. Nature does the rest - using the rockdust to pull carbon dioxide from the air and store it in the soil. With the help of Rachael James from Southampton University, Tom Heap and Tamsin Edwards check out a technique that could be applied to millions of hectares of the world's farmland.

Producer: Alasdair Cross Researcher: Sarah Goodman

Made in association with the Royal Geographical Society. Special thanks for this episode to Professor Heather Viles of the University of Oxford, Professor Larissa Naylor and Dr Adrian Bates from the University of Glasgow, and Dr Phil Renforth of Heriot-Watt University.

Giant fans are sucking in fresh air from the Swiss Alps and Iceland's frozen interior, capturing the carbon dioxide and turning it into fizzy drinks or burying it deep underground. Tom Heap gets up close to the extraordinary Climeworks device at the Science Museum in London and talks to the team that's developed it to ask if they've designed the solution to climate change or created a potent symbol of our failure to cut carbon emissions? Dr Tamsin Edwards of King's College London joins Tom to crunch the numbers.

Producer: Alasdair Cross Researcher: Sarah Goodman

Produced in association with the Royal Geographical Society. Special thanks for this episode to Dr Samuel Krevor and Professor Nilay Shah of Imperial College London and Professor Jon Gluyas of Durham University.