For years this port city on the edge of the Baltic has been considered one of the greenest in Europe. Now Helsinki wants to go a step further and make cars unnecessary by 2050.

Helsinkians take great pride in their relatively small, maritime capital with a population of just over 600,000. But the city is anticipating a dramatic population boom over the next few years and needs to be able to comfortably accommodate its new arrivals.

Parks and clean air are a source of civic pride in this city where green areas already make up 47 percent of space, so urban planners are devising a cityscape that also features fewer cars and thus cleaner air through lower carbon emissions.

While cars will not be banned, the city will do what it can to discourage people from using them, introducing better public transport, walkable green neighbourhoods brimming with services, and higher costs for parking.

City dwellers will be able to ditch their wheels as shops, schools and services will be grouped together within walking distance of their apartments.

And those who need to travel further to work will be able to hop on the city's swift network of metros, trains and tramways.

The head of Helsinki's Strategic Urban Planning Division, Rikhard Manninen, and his team are calling their new concept "boulevardisation", under which busy inner-city motorways are transformed into green residential boulevards.

"We will keep the green spaces by channelling most new construction projects into areas where highways now stand," Manninen told AFP. Reducing the number of cars, and replacing them with public transport, will go a long way toward improving air quality.

The new plan will also help the city cope with an anticipated population boom of 40 percent, or a quarter of a million residents, by 2050.

Helsinki aims to be carbon neutral by 2050, which means the city cannot discharge any more carbon into the atmosphere than its vast surrounding forests are able to absorb.

"Helsinki has already managed to cut down its emissions significantly... but in order to become carbon neutral by 2050 we need to gear up," said Alpo Tani, one of Helsinki's urban planners.

A key part of the solution is to address traffic, which accounts for around 20 percent of Helsinki's emissions.

The city estimates that without its plan, traffic emissions would be up to 30 percent higher by 2050.

- Growing pains -

Not everyone in Helsinki is thrilled to see car use discouraged. But the city centre sits on a small peninsula jutting out into the Baltic Sea, and while it makes for a pretty backdrop, it also slows traffic and stymies growth.

"It's a very bad idea (to cut down driving). I don't have anything against public transport but nothing can beat having my own car," Johan, 50, told AFP sitting in his car, explaining that it takes him only 20 minutes to drive home to Helsinki's adjacent suburb of Espoo where he moved in search of more space.

With all of its existing green areas, seascapes and roads, Helsinki is running out of space, planners argue. But the Helsinki Chamber of Commerce has called the new plan "oversized" and "unrealistic".

"The goal to channel all traffic growth in means other than cars is unrealistic while the city is expanding," said the chair of the chamber's traffic committee, Heikki Kovanen.

While some car owners moan, others welcome better public transport such as the extension of Helsinki's metro westwards to Espoo, due to open in 2016.

"The plan seems good and practical. Public transport can carry more people than individual cars," said Matti, a pensioner from Espoo out walking in Helsinki with his brother Mikko, who advocated even tougher traffic restrictions.

"We should adopt road tolls so that everyone doesn't pack into this small peninsula with their cars," he insisted.

- First skyscrapers under way -

Residents of Helsinki have for many years clung to the idea of keeping the city centre low and green.

So it comes as no surprise that many people grow anxious at the mention of new office towers or tall apartment blocks, and plans to reduce green areas.

Officials have promised not to take things too far.

The city's cherished Central Park -- a whopping three times the size of its New York namesake -- and other green areas will be reduced only slightly to make space for new housing, leaving 40 percent of the city as green areas.

And, Manninen vowed, "building upward will be permitted in some places, but not in the centre."

The foundations for Helsinki's first skyscrapers are currently being laid in a former harbour dubbed Kalasatama (Fish Harbour), which is to house some 20,000 people and create 8,000 jobs by 2030.

Kalasatama intends to showcase Helsinki's beautiful seashores with boardwalks and recreational areas.

The city council is set to approve the draft plan in 2016.