Homeless in Vancouver: Our urban tree canopy is fourth among major cities—if you believe MIT

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      The most tree-covered city in the world, according to online data released by the Massachusetts Institute of Technology (MIT), is not Vancouver, British Columbia. It is Tampa, Florida.

      Tampa’s tree canopy of 36.1 percent is ranked first out of 27 cities, by MIT’s Senseable City project, as the Guardian and other media reported Tuesday (November 5).

      Vancouver—which aspires to be the greenest city in the world—is ranked by the survey over 10 percentage points back, in a tie with Sydney, Australia, for fourth place, with 25.9 percent.

      The city state of Singapore took second place with 29.3 percent and Oslo, Norway, came in third with 28.8 percent.

      Of the two other Canadian cities that made MIT’s list, Montreal, is less than half a percent behind Vancouver with 25.5, while Toronto is firmly in the middle of the pack with 19.5 percent.

      Architecture, wealth, or trees—pick any two

      Paris, France, trails the list in last place with 8.8 percent—perhaps explaining why it is known as the City of Lights, instead of Trees.

      London, England—another undeniably world-class city—came fifth from last with only 12.7 percent tree canopy, while New York, New York—despite the fact that A Tree Grows in Brooklyn (or because there was just the one)—only managed two places better, with 13.5 percent shady coverage.

      Has Vancouver tree canopy grown so much in five years?

      Vancouver first used LIDAR to estimate the urban tree canopy by neighbourhood 2014.
      City of Vancouver

      Vancouver’s fourth-place finish when it comes to urban tree canopy is both pleasing and perplexing.

      The 25.9 percent tree canopy assigned Vancouver by MIT is a full 7.9 percent higher than Vancouver’s own estimate of 18 percent—arrived at five years ago, after the city’s first-ever LIDAR survey of its so-called Urban Forest in 2014.

      It is true that Vancouver has repeatedly stated that by October of 2019 the park board will have planted 125,854 new trees since 2010 and that the city revised its canopy coverage estimate up a whole percentage point for 2015.

      Assuming a steady one percent improvement every year since 2015 would put Vancouver’s tree canopy at 23 percent. That’s fully 2.9 percent below MIT’s estimate for the city but right between the estimate for Frankfurt (21.5) and Johannesburg (23.6).

      It has to be added that in its 2018 Urban Forest Strategy Update, the City of Vancouver makes no claim for a tree canopy above 19 percent and even points out that without Stanley Park the city’s tree canopy would only be 16 percent.

      And whereas Vancouver’s calculations of tree canopy have been based on rigorous overflights of the city using LIDAR (pulsed laser light), the 27-city survey of urban tree canopy just released by MIT was not meant to be particularly scientific—having been done using nothing more sophisticated than Google Street View.

      One data maven clarified, via Twitter, that MIT’s numbers represent a street-level “green-index”, including not just tree canopy but all visible green space, such as hedges.

      Urban hedges, which help suck up street pollution, are worth counting.

      But one has to wonder if MIT’s calculation of Vancouver’s “green-index” was indiscriminate enough to also include the many hectares of useless green artificial turf that covers city sports parks and a growing number of front lawns.

      Putting MIT’s fuzzy numbers and methodology aside, it is probably safe to say that urban tree canopy-wise, Vancouver is running well above the middle and near the top third of the pack and that our status as one of the world’s tree-hugging hot spots is secure for another year.

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