Lorien Nesbitt: Retaining urban greenness, including tree canopy and access to parks, still eludes us

Opinion: Vancouver is among the least equitable of Canada’s major cities when it comes to neighbourhood income and access to green space

Despite dozens of worldwide studies showing why green space in urban centres is essential to biodiversity and our physical, mental and even economic health, maintaining or increasing urban greenness, including adequate investment in tree care, is still eluding us.

Recently, Statistics Canada produced a report that shows cities across the country have less green space now than they did two decades ago. Municipal councillors have raised their voices in response, indicating they are not surprised by the results as they struggle to maintain tree canopy cover, public-access parks or even open, unbuilt areas, due to the pressures of climate change on urban vegetation and ever-increasing development demands.

When it comes to the many benefits of green space, what some would call “nature-based solutions,” no one can afford to ignore to the ample scientific data available on the topic. Over the years, the University of British Columbia’s faculty of forestry has conducted dozens of studies showing the importance of green space and where we are falling short.

In one such study, including more than 27,000 Metro Vancouver children between birth and age five, researchers looked at the effects of exposure to green space on children’s development. The study conclusively showed those children with exposure to greener environments exhibited better overall development than their peers with less exposure ti green space.

In another urban study, Vancouver ranked among the least equitable of Canada’s major cities when it came to neighbourhood income and access to green space. The study measured urban vegetation in 31 Canadian cities and found that in eight of them, urban vegetation was found to increase alongside income.

Finally, a UBC literary review paper published this fall showed more consideration needs to be given to youth and young adults when it came to designing urban green space. This demographic, representing ages 15-24, was found to be overlooked when urban planners were designing green spaces such as parks.

In making this argument for green space, it would be remiss to ignore the potentially competing demand for housing with which many urban centres struggle. Without careful planning, urban greenery can easily be lost to housing projects as the fundamental need for such developments continues to grow. Currently, housing and related infrastructure get priority over trees and other vegetation. If we wish to densify our cities while maintaining or increasing urban greenness, we will need to follow development approaches that leave sufficient space for vegetation and prioritize its care.

Certainly, declining urban vegetation is not unique to the Lower Mainland or even Canada. A recent review done in England and Wales, for example, concludes urban centres throughout these two countries have had significant green space losses. Perhaps most interesting, the review indicates the loss has been most apparent in more recent years, 2009 to 2021, where newer housing developments have reportedly 40 per cent less local green space than areas where the homes were constructed in the late 19th and early 20th centuries.

As cities struggle to address the complex issues of housing, greening, equity, and resilience, the percentage of people living in urban areas worldwide will continue to increase. The United Nations estimates that total to be around 70 per cent by 2050. This rapid urban growth means city planners and the communities they serve need to create inclusive, green, resilient cities while dealing with the potential impacts and encroachment on urban vegetation and all that it supports, including farmlands, wetlands and wildlife.

With recent statistics at everyone’s disposal and evidence-based decision-making tools to work from, we have a unique opportunity to reframe our thinking and become more creative when it comes to urban design.

City developers can look to the science and co-create their plans with urban forest professionals and urban residents to balance the need for denser housing with the critical need for green space. If they ensure their plans start at the neighbourhood level and truly attend to local needs and strengths, they are more likely to help build communities that feature equitable green space access.

The time has come to not only acknowledge this science, but incorporate it into a policy and planning framework so that future generations may be able to thrive from the many benefits a balanced approach to urban design will give us — liveable cities with equitable green space for all.

 Lorien Nesbitt is assistant professor, urban forestry and environmental justice, in the faculty of forestry at the University of British Columbia.