The trees that line the street and dot the parks in Canada’s cities do more than just add greenery to the urban landscape. According to a recent TD Bank report, Urban Forests: The Value of Trees in the City of Toronto, that city’s trees are worth $7 billion to the local economy. The city’s urban forest provides residents with more than $80 million in environmental benefits savings each year, including improving air quality and easing the burden of managing snow and rain. Craig Alexander, the chief economist at TD Bank and author of the report, explained its findings.

How did you determine the value of Toronto’s urban forest?
We attempted to assess the economic and social contribution that trees were making, and identified some core factors where trees have a significant impact: absorbing air pollutants, saving energy through shading and climate moderation, and sequestering carbon. We concluded that the urban forest in Toronto is worth about $7 billion or $700 per tree. Our estimation is probably low-balling the actual contribution. There are things you can’t put dollar value on.

How does the urban forest in Toronto provide residents with environmental benefits?
The wet-weather flow reduction by trees intercepts an estimate 25 million cubic metres of water. This really takes a lot of pressure off infrastructure in the city. Trees also improve air quality. Our estimation is that Toronto’s urban forest removes about one quarter of the annual emissions by industry in the city. That’s equivalent to the amount released by over a million vehicles.

How does the urban forest provide major cost savings to Torontonians?
By having an influence on the climate within the city. Because trees provides shade, they can reduce business and consumer use of air conditioners. You can put a dollar value on the savings trees provide, because without them you’d have to take action to mitigate the higher temperature, the increased amount of water and air pollutants.

How does the benefit of maintaining an urban forest outweigh the costs?
Trees are expensive. You not only have to buy it, but you also have to maintain it, and that can be expensive. We found that the annual maintenance cost on a tree in Toronto is roughly $4.20. We looked at the ways trees have a positive impact on the city, put a dollar value on those benefits, and found that the return far exceeds the cost. So while the city might be paying $4.20 to maintain each tree, the city is also getting a benefit that’s actually a $1.35 to $3.20 more than that $4.20 maintenance cost.

Who do you hope will pay attention to your report?
Policy makers, businesses and citizens across the country. Every community in Canada has trees, and I think the environmental considerations are absolutely critical.