At the top of the Eiffel Tower on a summer’s day, there’s a perfect view of the Champ de Mars, one of France’s most popular parks. For miles across the city, trees appear to fill the streets.
But the view might be deceiving. According to a new algorithm measuring the percentage of urban trees seen from a pedestrian’s perspective, Paris ranks poorly. The algorithm, known as Treepedia, was launched in 2016 by Senseable Cities Laboratory, a research group in MIT’s Department of Urban Studies and Planning, in collaboration with the World Economic Forum. It uses footage from Google Street View to evaluate and compare green canopy cover; the median generated is known as the Green View Index. Among the highest of the 27 cities currently measured are Tampa (36.1%), Singapore (29.3%) and Oslo (28.8%)
Paris, with a score of just 8.8%, is on the other end of the scale — unfairly, according to the city’s deputy mayor Penelope Komites. She says the project does not best represent the city because Google Street View rarely covers parks. “It doesn’t take into account the trees in the green spaces or in the woods, which are very important to Paris,” Komites says.
Yet even when taking into account parkland like the Bois de Vincennes, Paris scores low in terms of greenery. According to data from the World Cities Culture Forum, a network of local governments and cultural sector leaders, only 9.5% of Paris is made up of this kind of green space, compared to Vienna at 45.5% and Oslo at 68%. In the U.S., over one fourth of New York is allocated to parks. In San Francisco, the figure is 13%.
Increasing a city’s green coverage can not only lower urban temperatures, it can also be “extraordinary in terms of collective well-being,” says Carlo Ratti, the director of MIT Senseable City Lab. According to a study in April of around 95,000 people with mental health issues in cities, carried out by the universities of Oxford and Hong Kong, exposure to nature can reduce the chance of serious depressive disorders by 4%.
The idea of bringing trees into cities is a fairly modern one. That means older cities like Paris tend to naturally have less canopy than newer ones. “Even some affluent areas don’t have a good green coverage as they were built in older times with narrower streets and sidewalks,” Ratti explains. An exception in Paris are the large green boulevards scattered across the city, such as Boulevard Saint-Germain on the Left Bank of the River Seine, which Baron Haussmann designed in the 19th century. “But they are not the rule,” Ratti adds.
Meanwhile cities like Seattle, Miami and Sacramento, each founded in the second half of the 19th century, have a Green View Index of around 20%, more than double that of Paris.
The Parisian government is making an effort to boost greenery by planting 20,000 new trees in the city by 2020 — an objective that the Mayor …read more
Source:: Time – World