In September, Paris envisioned life without cars for a day as people walked and biked freely on the streets under clear blue skies. But Oslo is raising the bar with its plans to ban cars from the city center within four years. The move would rid private vehicles in an effort to reduce traffic and pollution in the heart of the city, where some 90,000 people work. The Norwegian capital will also divest fossil fuels from their pension funds, build more bicycle lanes and subsidise the purchase of electric bicycles for its citizens, all part of Oslo’s ambitious targets to slash emissions of greenhouse gases by 50% by 2020 compared to 1990 levels.