As cities around the world start to take climate change seriously, many of the goals are still in the somewhat distant-sounding future. New York City plans to cut emissions 80% by 2050. That’s more than 30 years away, and even that will be a challenge .

“Oh, it’s actually quite nice not to have cars coming down the street.”

Oslo is taking a different approach. The city plans to cut greenhouse gas emissions in half, compared to 1990 levels, in only four years. It’s faster than any city or country has made changes in the past. When France shifted to nuclear power from fossil fuels, they reduced emissions by about 5% a year.

But experts say that’s the pace needed if we want to try to keep global warming below 1.5 degrees Celsius, which is the most ambitious goal countries agreed to at the Paris climate talks, and the target that most scientists say is safest if we want to keep the climate–and all of the systems that humans rely on for survival–stable.

“[Oslo] is certainly the only city or region that I know of that has a goal which is consistent with 1.5 degrees,” says Glen Peters, senior researcher at Norway’s Center for International Climate and Environmental Research.

The city has different challenges than some others. Electricity comes from hydropower, and though recent research suggests some dams aren’t quite as clean as they seem, they’re still better than relying on fossil fuels. Rather than revamping electricity, Oslo will have to focus most on problems like pollution from waste disposal or transportation.

In 2015, the city decided to ban private cars from the city center; the new plan builds on that goal. Taxis will stop using gas by 2020; public transit will also go fossil-free. New infrastructure will help reduce freight emissions. The city is also rolling out new parking restrictions, tools, and building more bike lanes.

Unsurprisingly, there has been some resistance. “Like every country, I guess, people are addicted to their cars, so it would be really tough to reduce,” says Peters. Adding bike lanes also means taking out parking spaces, which has caused waves of annoyance.