Densifying big cities is the low hanging fruit in the fight against climate change. Building more homes and increasing their population is the most impactful thing cities can do for the climate.
Cities are responsible for 75% of global energy consumption and 80% of green house gas (GHG) emissions. By making efficient use of land and other resources, they’re also the greenest way to house a growing global population. These efficiencies are amplified by the density of cities.
Consider, New York City. The largest and most dense city in the U.S. is one of the highest net emitters in the country but its per capita emissions are only 29.7% of those in the U.S. as a whole.
At a point when international, national, and provincial climate action is challenged, cities find themselves leading the fight against climate change. Yet climate strategies in many cities have optimized for the wrong outcome.
Optimizing for the wrong scale
A primary target of Toronto’s climate strategy is to cut emissions by 65% by 2030. The message is clear but oversimplified. Hard numerical targets prioritize arbitrary local metrics over global impact.
Only measuring the success of Toronto’s climate strategy against hard reductions in local emissions overlooks urban density as a tool to reduce national emissions because the benefits are only evident at a broader scale.
Building new housing that allows someone to move to Toronto from somewhere with higher GHG emissions per capita can reduce emissions nationally while increasing net and per capita emissions in Toronto.
At a local level, an additional person makes hard reductions in emissions more difficult. They challenge Toronto’s ability to reduce emissions by 65% by 2030. Nationally, the migration of people to big cities reduces the country’s carbon footprint. In the end, it doesn’t matter if Toronto meets its emission targets if Canada continues to be one of the highest emitting countries in the world.
Many cities are on their way to net-zero emissions but the Paris Agreement goal to keep rising global temperatures to 1.5°C is slipping out of reach. Even if countries meet their current commitments, emissions in 2030 will be 38% higher than required to meet that target.
https://www.unenvironment.org/resources/emissions-gap-report-2018
Climate benefits of density
Density isn’t equivalent to sustainability but recognizing the climate benefits of density in local climate strategies would allow cities to do more faster.
A London School of Economics study of large global cities found that even a modest blend of pro-density housing and transit policies could reduce those cities' emissions by a third by 2030.
Peter Calthorpe’s research demonstrates that through urban density alone, the United States could achieve half the carbon reduction needed by 2050, for the country to do its share in holding global temperature rise to 2°C.
Crisis planning in Toronto
As successful as Toronto has been, it is also a city in crisis. Adding to an extended and severe housing crisis, city council recently declared a climate emergency. Densification can contribute to sustainability and make housing more affordable.
To these ends, Toronto’s Housing Now initiative can leverage density through the redevelopment of 11 city-owned properties. Because they own the land and write the rules, the city has a rare opportunity to innovate. Yet the results have been underwhelming.
705 Warden Ave, Toronto: https://smartdensity.com/createto-housingnow-705-warden-ave/
On the 7 acre site near Warden subway station, only 466 units have been proposed (66 units per acre) along with 1 parking space for every 1.4 units. Instead of pushing boundaries, Housing Now has typically proposed less density than nearby private development of similar scale.
Recognizing the climate benefits of density in the planning rationales for the Housing Now sites would support building at a much larger scale than existing regulations would permit.
What does fighting climate change in cities look like?
The Squamish Nation recently voted to move forward with Sen̓áḵw, a ground-breaking development proposed for downtown Vancouver.
The project would see 6,000 units in 11 energy-efficient towers on 11 acres for a remarkable 545 units per acre (in contrast to Housing Now’s 66 units per acres at Wilson subway station). Designed to prioritize sustainability and transit, Sen̓áḵw will emphasize green spaces and limit parking with only 1 space for every 10 units.
It's no coincidence that this innovation is occurring outside the existing municipal planning context. Located on reserve land, the proposal isn’t subject to many of the planning regulations that apply to the rest of the city. This allows the project to push the limits of city building based on the priorities of the Squamish Nation.
The Squamish Nation is uniquely positioned to appreciate and apply urban density as a tool for sustainability. The project is still in the early stages, but its ambition serves as an example of how cities can use density to combat climate change.