Statistics Canada's first survey of urban green space shows cities across the country are getting greyer and browner, with Windsor recording one of the largest decreases in green space.
In a new report, the statistics agency used satellite data to assess the greenery of parks, trees, lawns and backyards in 31 cities across Canada from 2001 to 2019.
In the first year of the study, 76 per cent of Windsor was classified as green in the 2001 period. In the 2011 period, it went up to 85 per cent but decreased to 56 per cent in the 2019 period.
According to the study, the largest decreases in greenness from 2001 to 2019 occurred in Winnipeg, Milton, Kelowna, Vancouver and Windsor.
These larger decreases in greenness were likely driven partly by the contributions of urbanization, as well as moderate drought conditions in 2019, while trees in Winnipeg and Windsor also experienced insect damage and mortality - with the study citing the impact the emerald ash borer had on trees in some regions of the country.
Study co-author Jennie Wang ('WONG) says some natural factors can impact the score.
"Windsor, in fact, had some damage from the Emerald Ash Borer, also abnormally dry weather conditions. In fact, I believe there was a drought in the later period in Windsor, at least abnormally dry weather, so that would be influencing the score that we saw over that time," she says.
The beetle's identity was confirmed in Windsor in July 2002, killing thousands of trees across the region.
Wang says Windsor did not have a large population increase over the study time period.
"So in Windsor, one would expect, that development aspect might still be a cause, some of these other fluctuations might also be causing the level changes we saw in a given year," she says.
The study found about three-quarters of large and medium-sized cities were less green in 2019 than they had been 20 years earlier.
Wang adds that urban greenery provides many benefits, from reducing air pollution and noise to helping keep cities cool.
She adds that the conditions can change from one year to the next and you really need to assess the data the see which factors will have a long-term inpact on the ground.