To meet today's nomads, the film director Sibylle d’Orgeval had to cross Kyrgyzstan, from the capital Bishkek to Lake Issyk Kul. Then through the mountains and high pastures where the shepherds live she'll head for the south of the country.

No sooner had they arrived in Mexico than the Spanish settlers discovered silver. They then constructed a road 3,000 km long to transport the silver extracted from the mines northward, then towards the West. A road full of hopes, and riddled with pitfalls and dangers. This is the road Christopher Cousin is going to take, from Mexico to the southern United States.

The South American country of Ecuador has had a chaotic history, punctuated by coups d'états and dictatorships. But in 2007, with the election of President Rafael Correa, the people of Ecuador chose a new way: a so-called citizens' revolution, based on the "living well" philosophy of the Quechua Indians.

When you arrive in Africa, it's always pretty much the same. The plane lands at night, and as you step outside you're enveloped in the damp heat. Then you set off into a night of car horns, dust and headlights. To get your bearings you impatiently wait for the morning, when the sun rises and you can finally discover the city.

Brazil is a giant that's too often reduced to its wild samba, its magical football and its endless beaches. But behind this fantasy lurks an economic colossus and agricultural titan, a force of the future which is already playing a major role in this burgeoning 21st century.

The Gulf Stream is one of the most powerful tidal currents on the planet. It warms our coastlines in winter, it harbours billions of species. To get to know the famous current better, we slipped into its wake, heading across the North Atlantic.