People Fixing the World

Old ships, powered by the wind, are sailing small amounts of cargo around the world again to help cut pollution. Some of them were built more than 100 years ago. The shipping industry moves 80% of traded goods around the planet. But the diesel engines that propel modern cargo ships through the oceans burn the dirtiest type of fuel. Nick Holland speaks to sailors and brokers who, for the sake of the environment, are breathing new life into these vintage vessels. And he hears how new types of sails could get monster-sized modern cargo ships using the wind as well. Producer / Reporter: Nick Holland

Scientists in Italy have discovered that trees generate an electrical charge every time the wind blows strongly enough to make their leaves touch one another.The researchers, from the Italian Institute of Technology, have managed to harvest enough energy this way to power 150 LED lights from a single leaf.We meet them, and others, who are trying to make use of untapped, natural sources energy. We hear from a project trying to produce electricity from the interaction of fresh and salt water where rivers meet the sea.And we talk to a geologist in Iceland, who’s helped dig nearly 5km beneath the surface of the Earth. At that depth, the temperature can be about 600C - the idea is to mine the heat and turn it into energy. Producer/Reporter: Daniel Gordon Picture: Getty Images

A clever invention is saving the lives of hundreds of children. Pneumonia kills about 1.4 million children under five every year. Treatment with concentrated oxygen could save many of them, but the machines that make it need a reliable source of electricity. Some hospitals have frequent power cuts, though, which can be fatal. So scientists in Australia and Uganda came up with an innovative way to produce oxygen by separating it from the rest of the air, using a vacuum created by running water. Then they designed special bags that can store and deliver oxygen – even when the electricity cuts out. Their systems have provided oxygen for hundreds of sick children in Uganda. People Fixing the World hears the story of these remarkable inventions. Produced and presented by Ruth EvansPicture credit: Peter Casamento

We all know that sport is great for our health - and if you’re talented it can bring you great riches. But this week we look at how sport is changing lives and giving hope to young people leading the toughest lives. In Cape Town, South Africa, a British surfer noticed how kids from poor townships hardly ever went to the beach. So he started giving them free surfing lessons. Now hundreds go along each week to get “surfing therapy”. Not only is surfing giving them a buzz, it's helping to improve their life chances. In Afghanistan we meet the people who have brought skateboarding to the streets. As well as being an exciting challenge, it’s giving girls in particular a safe place to do sport and changing their outlook on life. And in one of the more deprived parts of London we find out how horse riding - a sport normally associated with the elite - is now inspiring young people from all backgrounds. Reporter/Producer: Richard Kenny

There’s a technology on the block which has the power to change all kinds of things for the better. If that power is harnessed, it has the potential to end corruption, protect your online identity and a whole lot more. Start-up companies and charities are using it in everything from tuna supply chains to medical records and ID documents and everything in between. The technology is blockchain and on this episode of People Fixing the World, we’ll explore whether its great potential can be realised. Produced and presented by Tom Colls Image: Blockchain illustration (Getty Images)

We visit farmers growing lettuce, herbs and strawberries indoors in the middle of cities. The plants are stacked up on shelves in vertical farms that use hydroponics and aeroponics to cultivate them.The idea is to grow food closer to where it’s eaten. At the moment, cities get most of their produce delivered from far away, but transporting it uses energy, while fruit and veg can lose their freshness in transit. We visit two European companies hoping to change the supply chain. One makes indoor farming units for food retailers, restaurants and hotels, and the other grows strawberries in shipping containers on the outskirts of Paris. We find out if these pioneers of European urban farming are able to feed our growing cities. Produced and presented by Dina Newman.Picture credit: Getty Images

People around the world are coming up with ways to make the world a quieter place, from portable sound barriers to schemes to stop people honking their car horns.The trouble is that noise from traffic, railways, builders, even neighbours, can have a huge impact on our health and wellbeing, according to the World Health Organization.One of the solutions we look at reduces decibel levels around building sites and music festivals, while another collects acoustic data to help local councils enforce laws if people are being too noisy. Also, a woman in India is doing her bit to reduce noise levels on the streets of Mumbai. Presented and produced by Anisa Subedar Picture credit: Getty Images

Robot shuttles and buses on demand are being tested to persuade more people to use public transport. Tallinn in Estonia and Luxembourg have even made travel free. The aim is to tackle the impact of one billion cars on the world's roads, which have brought some cities to a virtual standstill. But in order to tempt people away from their cars new incentives are needed.Claire Bates tries out schemes that are being developed across Europe.Presented and produced by Claire Bates

It has taken him 40 years, but Omar Tello has turned a patch of exhausted farmland in Ecuador back into rainforest. One of his biggest challenges was repairing the soil. His land was so degraded he had to make enough new soil - from unwanted wood shavings and chicken manure - to cover the entire plot. That alone took about 15 years. He also travelled deep into the Amazon for days at a time, looking for seeds and plants he could rescue. Now his forest is flourishing and the wildlife has returned - it is home to snakes, toucans, monkeys and many other animals. And he is sharing what he has learned to encourage others to protect the rainforests instead of cutting them down. Presented and produced by Jo Mathys.

Human sewage contains lots of valuable nutrients, so should we be recycling it? One of these nutrients is phosphorus, a key ingredient in fertiliser. We need fertilisers to meet the demands of the planet’s growing population, but there is a limited supply of phosphorus. Once it finds its way into the sea it becomes impossible to recover. And yet we all excrete about half a kilogram of the stuff a year, making cities a potentially rich source of the element. In the Netherlands human sludge is already being processed to recover phosphorus and recycle it into a high-tech fertiliser which will not leach into the environment. Reporter: William Kremer Photo: Getty images