Major global cities failing to meet tree canopy goals: Australian study

SYDNEY, Nov. 20 (Xinhua) — Research has found that major global cities, including Australia’s two largest cities, fail to meet international goals for tree canopy coverage.
In a new study published on Wednesday, researchers from Melbourne’s RMIT University measured access to nature for eight major global cities including Sydney, Melbourne, Amsterdam, Buenos Aires, Seattle, Denver, New York and the city state of Singapore.
They measured 2.5 million buildings in the cities on a sustainable cities measure known as the “3-30-300” rule that states every house, school and workplace should have a view of at least three trees, be in a neighborhood with 30 percent tree canopy cover and be within 300 meters of a park.
It found that most buildings in the eight cities and city state had views of at least three trees but that Singapore was the only one where over half of buildings, about 75 percent, were in neighborhoods with adequate tree canopy cover.
Only three percent of buildings in Melbourne had adequate neighborhood canopy cover despite 44 percent having views of at least three trees.
In Sydney, 84 percent of buildings had views of at least three trees but only 17 percent passed the canopy cover test.
Thami Croeser, lead author of the study from the RMIT Centre for Urban Research, said that increasing canopy cover is urgent to cool down cities.
“We know depression, anxiety, obesity and heatstroke are more prevalent in urban areas lacking access to shady tree canopy and green open spaces,” he said on Wednesday.
“Studies say we actually need at least 40 percent canopy cover to substantially lower daytime air temperatures, so the ’30’ metric is the bare minimum; most buildings we studied don’t even reach that goal.”
Among the others studied, Seattle fared the best with 45 percent of buildings passing the 30 percent canopy cover benchmark followed by Buenos Aires at 22 percent, Denver at 18 percent, New York at one percent and Amsterdam at zero percent.
At least 20 percent of buildings were within 300 meters of a park in all eight cities and city state, with Singapore faring the best at 80 percent and Buenos Aires the worst at 23 percent. ■