Down to Earth

Many of the factories that once dotted the outskirts of French cities such as Paris, Lille and Marseille have long been closed. But scars remain: pollutants in the soil including petrol, solvents, cyanides, heavy metals and even traces of radioactivity. There are nearly 7,000 former industrial sites that are polluted or potentially polluted in France and another 300,000 sites still need to be assessed. These wastelands are often gold mines for developers and can also help reduce urban sprawl. But reclaiming this contaminated land is costly and rarely a simple exercise.

Insects have long been touted as a solution to cut the environmental impact of food production. But today they are closer than ever to flooding our supermarket shelves. Europe's food safety authority, EFSA, has approved the humble yellow mealworm safe for consumption, paving the way for insect-based delicacies on a large scale. Down to Earth explores the promising culinary future of six-legged snacks.

French circus workers are warning that a looming ban on the use of wild animals in travelling shows would see their industry brought to its knees. It also raises questions for their star performers. Today there are 700 wild animals in the country's circuses, including 500 big cats. What does their future look like after life on the stage? The Down to Earth team takes a closer look.

Fashionistas are spoiled for choice in tints, shades and hues, but our rainbow wardrobes come at an environmental cost: synthetic dyes, derived from petrol, are responsible for nearly 20 percent of water pollution by industries. For solutions, we look to the old and the new: rediscovering the woad plant, also known as pastel, whose blue pigment coloured the gowns and shawls of medieval Europe; and visiting PILI's laboratories to meet the team harnessing the power of bacteria in the hope of creating dye on an industrial scale without relying on fossil fuels.

When it comes to energy efficiency, France is lagging behind its European neighbours, trailing Germany, Sweden, the United Kingdom and the Netherlands. Nearly seven million French people live in residences known as "passoires énergétiques" or energy sieves. These homes have an energy rating of F or G, meaning it's too cold in winter, too hot in summer and importantly, it adds considerably to the country's carbon footprint.

They pierce through the heart of most cities, yet their potential is often overlooked. Rivers are now offering a modern mode of transport and a cleaner way of delivering goods. The Down to Earth team takes a closer look.

Hemp and marijuana are often described as cousins because they come from the same cannabis plant. But unlike marijuana, hemp has low levels of the chemical tetrahydrocannabinol (THC), meaning smoking it has little effect. Today hemp is recognised as one of the world's most ecological agricultural crops, prompting a comeback in Europe.

Every day, we produce large quantities of urine, at no cost. So instead of flushing it down the toilet, what if it was transformed into something useful? The Down to Earth team takes a closer look.

For more than half a century, humans have required all new drugs to be tested on animals. Today, ethical alternatives are emerging. But can they replace animal studies? The Down to Earth team takes a closer look.

It's the most abundant element on Earth: hydrogen. Could it help us fly commercial airplanes with zero emissions by 2035? That's the promise made by Airbus as the aviation sector faces an unprecedented crisis fuelled by the Covid-19 pandemic and growing calls for a green recovery. But hydrogen is energy-hungry to produce and bulky to store. So is it a viable promise?