In his goal to reduce green house gas emissions by 30% by 2020, David Miller introduced the specific aim to double the tree canopy over the city. His goals are “aggressive, but workable” according to Councillor Paula Fletcher, chair of the parks and environment committee. At present, Toronto’s canopy covers 17% of the city. This might seem a trifling percentage in comparison to Washington, which has 40% canopy coverage and Ottawa, 27%.
Miller's plan may require some painstaking effort to succeed, but could have enormous benefit if it does. Incorporating trees into the urban environment would serve to reduce the amount of fossil fuels we burn and ease the damage of deforestation – the two main roots of climate change. Right now, homes and other buildings account for 30% of the greenhouse gas emissions in the country. Design and sustainability, both significant objectives in Toronto, can’t be sacrificed for one another. They must work together.
The city doesn’t “breathe” as well as a forest, contributing large quantities of carbon to the atmosphere with few sources of absorption. The earth, in order to give warmth to support life, needs a reasonable amount of greenhouse gases. Carbon dioxide appears naturally in the atmosphere, exhaled by humans and involved in the photosynthesis of plants. Carbon is kept in check by a natural carbon cycle, a system which creates a balance between the carbon emitters (humans), and the carbon absorbers (plants). Oceans, land and air are all involved in the process.
After the industrial revolution, when humans began messing with the carbon levels in the atmosphere, the earth began to see increasing quantities of carbon being pumped into the system. And it’s been rising steadily since, resulting in a 1.4 degree increase in global average temperature. This might not seem like a lot, but consider the fact that the global average temperature during the last ice age was only 4 – 7 degrees colder than it is today, according to the Intergovernmental Panel on Climate Change. The increase refers to the average temperature, not explicitly presenting the extremes on either side.
The city has taken a lot less time to grow than the forests, and we can't undo what has been built. But by adding trees into the urban landscape, we can contribute to the solution of the unbalanced carbon cycle. Placed around a house or on a rooftop, trees can cool a building by 40%. Cutting back on air conditioner reliance means a decrease in the human- made greenhouse gas hydrofluorocarbons. An appropriate mix of trees can filter 88% of air pollution in a park, or 70% in a street setting. The benefit isn’t just limited to homes and buildings. On the streets, trees slow rain fall and absorb water, reducing rain flow into our sewers. More trees on the street means less overflow from sewers into the lake.
More trees would attract wildlife, make the city more aesthetically pleasing, and create more jobs. The benefits are numerous. Trees and urban design are a winning team, combining to reconcile urban culture and nature, a gap that must be bridged in order to achieve a truly sustainable city. Restoring an eco system is slow and demanding process. And unlike simply building a condo, it is unpredictable. But adding these lasting structures to the city’s infrastructure would have a greatly advantageous impact on our environment, our resources, and our money.
The potential difficulties of Miller's plan lie in the nature of plant life. Will the slow growth of trees be frustrating enough for us to scrap the plan and come up with yet another quick and easy solution? Most of the trees that make up the canopy in Toronto were planted over a century ago, meaning that the skinny ones planted in addition will take equally as long to reach full growth. Cultivation in the urban environment won’t be easy, either. City trees die quickly in the drought of the hot summer months, as they bake against the concrete buildings and roads. If trees are to survive in the city, they would need to be planted in large groups and carefully tended.
Cities are built primarily with humans needs in mind. They create the illusion of a world solely for us. The goals of Mayor Miller provide promising step to a sustainable Toronto. So far, we have 8 LEED certified buildings in the city. The green building rating system commends the utilization of conditions like natural light, plants, local building materials, bike storage etc. It is a country wide initiative, taking into account the Canadian climate, construction regulations and practices. Ryerson’s 105 Bond St. was recently certified Gold by LEED, making it the first University building certified in Ontario. The building has a negative ecological footprint, diverting most waste materials from the landfill.
Toronto can and should set an example for other Canadian cities. Doubling the tree canopy is within our reach, and the cultivation of these entities will force us to recognize the true value of trees. The greater the esteem we assign them, the greater the benefit they will provide. Urban design and sustainability can no longer afford to clash. A green infrastructure starts with a return to the architecture of the natural world.
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