How cities around the world tackled air pollution

• The German city has 500 km of bicycle routes, tramways and a cheap, efficient public transport system
• Parking near homes is forbidden in the suburb, with owners having to pay 18,000 euro for a spot on the edge of town
• For going car-less, people get cheap housing, free public transport and ample bicycle space in return

The city in southern Brazil is often hailed as the “greenest city on Earth”. Close to 70% of the city uses public transport — one of the biggest, lowest cost systems in the world — to commute. This has decreased air pollution and traffic.

It began with a street design that provided express lanes for buses. Other innovations include bigger buses for more capacity; and pre-payment so that bus drivers do not have to issue tickets. The city also increased its green cover from one park to over 50 square metre of green space per person.