Explore the Urban Canopies of Major Cities With Treepedia

Urban trees are Mother Nature’s most remarkable multitasking miracle workers. Not only do they perform typically tree-ish tasks like mitigating stormwater runoff, providing temperature-lowering shade, sequestering carbon and providing crucial habitat to city-dwelling critters but they also have a knack for deterring crime, boosting our moods and helping us to live healthier, more active lives.

Acknowledging the wide-ranging — and frequently life-saving — benefits of urban trees, a new project from Senseable City Lab, a social innovation incubator at the Massachusetts Institute of Technology (MIT) helmed by never-dull Italian-born architect and engineer Carlo Ratti, sets out to explore exactly how dense and, in turn, how beneficial the urban canopies found in 12 different major cities across the globe are.

Developed by Senseable City Lab in collaboration with the World Economic Forum, the Google Street View-harnessing project takes the form of a nifty interactive web platform with an appropriately catchy name: Treepedia.

While the map and statistic-heavy website itself can be a bit daunting at first view, the ultimate goal of Treepedia is rather straightforward: to provide residents of the dozen featured cities — Boston, Seattle, Vancouver, Toronto, New York, Paris, Los Angeles, London, Geneva, Sacramento, Tel-Aviv, and Ratti’s hometown of Turin — with a more concrete understanding of the urban canopies existing in their own sometimes not-so-lush backyards. Furthermore, as a press release explains, “Treepedia will allow city dwellers to view the location and size of trees within their communities and to submit input to help tag, track, and advocate for more such trees in their cities.”

Treepedia's Green View Index is based on Google Street View data and not satellite imagery. (Image: MIT Senseable City Lab)

Elaborates Ratti:

As many cities experience warming temperatures, increased storm frequency, and continued air pollution, the well-being of our urban trees has never been more important. We present here an index by which to compare cities against one another, encouraging local authorities and communities to take action to protect and promote the green canopy cover.

Initially launching in 10 cities (two more were just recently added) with plans to further expand, the basic function of Treepedia is to encourage urbanites to take note of areas in their cities are “green and not green.” In the future, Ratti and Co. plan to enable Treepedia users to “add unique tree information on an open-source street map and engage with city officials in order to request that new trees be planted in certain areas.”

This feature is somewhat akin to the New York City Department of Parks and Recreation’s wonderful New York City Street Tree Map, which identifies and catalogs the more than 675,000 arboreal specimens that line the streets of the five boroughs.

The “green” on display on Treepedia’s maps is a visualization of the Green View Index, a special metric system conceived by Senseable City Lab that utilizes Google Street View panoramas to compare the tree cover — or lack thereof — in a range of different cities. As the project notes, by using Google Street View in lieu of bird's-eye satellite imagery, “we represent human perception of the environment from the street level.”

The leafiest cities of them all

So then, which of the 12 cities represented so far on Treepedia rank the highest on the Green View Index?

Not surprisingly, Vancouver ranks highest in tree canopy coverage with 25.9 percent. In other words, nearly 30 percent of the scenic — and stupendously expensive — Canadian city’s streets are blessed with tree coverage. As noted by Vancouver Metro, however, this figure is a generous one compared to satellite-based assessments conducted by the city itself that show tree coverage of only 18 percent.

Following Vancouver at the top of the rankings are fellow West Coast cities Sacramento (23.6 percent) and Seattle (20 percent). Geneva and Toronto also fared well with 21.4 percent and 19.5 percent, respectively.

Urban forestry experts from Toronto reacted to the city's high Treepedia ranking in a similarly cautious manner as their contemporaries in Vancouver. While she welcomes the news of Toronto's notable current greenness, University of Toronto forestry professor Sandy Smith tells the CBC that residents shouldn't necessarily assume that the city's urban canopy will always be as dense. "Development pressures are so high, if we're not really careful and don't really focus, we will end up like London and Paris and New York," Smith explains.

On that note, of the 12 current cities mapped Paris has the least impressive tree coverage at 8.8 percent. However, it’s worth noting that Paris’ population density is far higher than some of the more spread-out cities that rank significantly higher in terms of tree coverage.

New York City is another city that ranks lower on the Green View Index (13.5 percent) but has a higher-than-average population density. Yet with a population density of nearly 11,000 people per square kilometer, the Big Apple is nowhere near as densely populated as Paris, which is home to a staggering 21,000 people per square kilometer. Essentially, this all means that certain sections of these cities are so densely populated people that there’s simply little room for trees and other greenery to be planted.

As mentioned, one significant aim of Treepedia is for residents in these less-than-green neighborhoods to take action by imploring city authorities to get plantin’.

Finding shade in the Big Apple

The Brooklyn waterfront and Midtown Manhattan could do with a bit more green. (Image: MIT Senseable City Lab)

Viewing Treepedia’s map of New York City, my home, isn’t all that surprising. The Upper East Side and the Upper West Side, the leafy and moneyed neighborhoods flanking Central Park, are awash in green dots that indicate extra-dense tree coverage. As you move south down the island of Manhattan, there’s a sparse scatting of red- and orange-dots in Midtown indicating lesser tree coverage. The green picks up again in downtown neighborhoods such as SoHo and the West Village.

As with all cities that appear on Treepedia, public parkland, private property and other tree-heavy areas of New York City that do not appear on Google Street View are omitted from the maps. This explains why Central Park and Brooklyn's Prospect Park, for example, appear as large brown-ish hunks complete devoid of green.

The Brooklyn waterfront, where I have lived for 10 years, is noticeably absent of any significant tree coverage, although things get noticeably greener as you move inland toward some of Brooklyn’s denser residential neighborhoods, some of which are more suburban in character. Judging by the map, my neighborhood has a couple of great park but is virtually tree-free, although a few lone — but much appreciated — young trees planted on my street following Superstorm Sandy do appear on the map.

Large swaths of Queens and Staten Island are, predictably, awash in green dots.

Do you live in one of the 12 cities mapped on Treepedia? Check out the site to see how your own neighborhood fared in terms of tree density and which neighborhoods in your city could use some tree TLC. And if your own city isn’t yet featured on Treepedia, from the sounds of it there’s a good chance that it could be in the near future.