Making 90% of our new buildings from wood, rather than concrete and steel, could cut global CO2 emissions by 4% - more than the climate footprint of flying. How? Growing trees absorb carbon dioxide from the air and when used in construction, that CO2 remains stored in the wood – carbon captured in your beams, floors and walls. Now, treated timber can be versatile enough to build housing estates and strong enough for skyscrapers – or “plyscrapers”. Tom Heap explains how it all works – and explores the benefits of living in a more wooden world. “Plyscrapers” are just one idea featured in the Radio 4 series 39 Ways to Save the Planet.

During the coronavirus pandemic, many offices were closed as people were urged to work from home. But lots of workers found they were able to do their jobs perfectly well from home, even if they missed some aspects of office life.

What does this mean for the future of the office? Is it necessary for productive and happy workforce? Some companies have decided to base their staff at home forever – others are considering a range of different scenarios.

One proposed solution involves workers coming into the office on Tuesdays, Wednesdays and Thursdays and working from home on Mondays and Fridays. Others are adopting “asynchronous working” - allowing people to work when and where they feel most productive. So is going into the office five days a week a thing of the past?

The average person eats about 40kg of meat per year. In developed countries, it’s double that. 80% of all farmland is dedicated to meat and dairy production. That’s about the size of Europe, the US, China, and Australia combined. Meat and dairy typically provide 18% of our calories, but account for 60% of greenhouse gas emissions from agriculture. With experts now advising cutting down the amount of meat we eat to help reduce climate change, here’s a thought experiment - what if the whole world turned vegan?

The Black Death of 1349 wiped out more than 50% of England’s population - but it also helped end the Hundred Years' War between England and France. The Spanish flu of 1918 claimed more than 50 million lives globally, but it also gave us a much better understanding of infectious diseases and spurred the development of public health systems. And both the National Health Service and the United Nations were set up soon after the Second World War. The BBC's Amol Rajan looks back through history at how crises have often led to profound changes in society, and imagines how the coronavirus pandemic might transform the world.

Welcome to the city of the future - a smart city that knows everything about you. From how you like your coffee, to whether you've broken the law. Or even if you've grown a beard. Sound far-fetched? While the smart city we're about to tour doesn't yet exist, all of the parts do. They're all components of real projects happening all over the world. Put them together and this is what life may well be like in the not-too-distant future. Made with the help of Theo Tryfonas from Bristol University.

Around 30% of our planet is covered in trees. Trees are majestic, help biodiversity and absorb CO2. But we’re cutting them down at an alarming rate. It’s estimated that since the start of human civilisation, we’ve cut down almost half the trees on Earth. What would happen if all 7.7 billion of us planted a tree?

Could our ‘number twos’ be the answer to some of the world’s biggest problems? The average adult flushes away 730 litres of urine and around 91kg of faeces every year. From modern treatment plants able to convert our never-ending supply of poo into biogas to power homes and vehicles, to recycling sewage to extract valuable minerals such as phosphorus which is vital for fertilising soil – can poo help us save the planet?

First greeted with optimism and endless possibility in the 1950s, for many, mention of nuclear power now provokes concern – fears of radiation from nuclear waste and the disasters at Chernobyl and Fukushima front of mind. But as the climate crisis deepens, and the world’s energy demands continue to grow, the quest for a low-carbon future makes nuclear power hard to ignore.