The mature neighbourhood tree canopy must be protected. Not only does it provide an enormous benefit to the beauty and enjoyment of our city, it helps us meet our climate change objectives, keep our properties cooler in the heat waves, assist with run-off and many other issues.
Numerous other cities have recognized the important role that trees play and have taken steps through zoning and bylaws to protect trees, especially when their removal is motivated by developers. Of course, our desire to protect trees must be balanced with the removal of dangerous or destructive trees which are hazards.
Later this year, the administration will be proposing opportunities to further protect trees located on private property. Sign up to join the conversation.
Until the City Charter was introduced in 2018, Edmonton did not have the authority through the Municipal Government Act to regulate private trees outside the zoning bylaw, said Travis Kennedy, the city’s general supervisor of open space operations.
Administration is currently in the process of reviewing whether that expanded authority will allow for regulation going forward. Potential options will be presented to the urban planning committee in June.
Protecting private trees would help the City of Edmonton meet its goal of building a tree canopy coverage of 20%.
“So we’re talking about doubling the forest canopy,” Bajer said. “I think you could even argue that 20% is too low of a number and that maybe we should be reaching for 30% to 40% canopy.”
The benefits of more greenery go beyond counteracting the heat island effect, he added.
“Just purely on a well-being standpoint, having access to green space is important,” Bajer said. “We also know that the amount of green space is not equitable across cities, and so certain neighbourhoods have more access.”
The inequitable distribution of greenery makes some communities are more prone to other environmental challenges, such as flooding. “Green space tends to be permeable and can be an important piece of green infrastructure that can actually do a lot of the heavy lifting so that you don’t have to depend on hard, expensive infrastructure to mitigate some of those things,” Bajer said.
That’s also an argument for spreading green space around instead of confining it to the river valley, though that’s also an important part of connecting the city to nature. A move is afoot to create a national urban park in the Edmonton region, with the goal to provide “better access to quality green space for Edmontonians” as well as to act as a nature-based climate solution, Parks Canada said in an announcement on March 14.
As for other solutions that could help with rising temperatures, Agrawal suggested allocating more spaces for parks, or adding green roofs to large commercial and residential developments.
“Hopefully that would help, but obviously it will not bring (the temperature) down to the same level as the rural surroundings,” Agrawal said.
Agrawal and Welegedara’s research, which was measured using satellite data, weather stations, and other sources, is supported by similar findings by Statistics Canada. Its report shows a decrease in Edmonton’s greenness between 2001 and 2019, based on the classification of urban pixels in satellite imagery as green or grey — with grey marking “areas that are predominantly covered by buildings, impervious surfaces, bare soil, and low-density vegetation.”
The University of Alberta researchers plan to continue their work on the urban heat island effect, and the next step is to look to the future. They’ll be exploring what would happen if various factors changed. The goal is to wrap up their research by this fall.