What Role Do Cities Have in the Fight Against Climate Change?

Jun 5, 2024

Every level of government, be it federal, provincial, or municipal, are enacting policies to lower their greenhouse gas emissions in response to the established 1.5°C warming threshold. Despite that limit, the past 9 years have been the hottest on record with 2023 being the hottest “by a long shot.” Global average temperatures soared to 1.48°C above pre-industrial levels, eclipsing the previous 1.25°C record set in 2016. The United Nations reports that 75% of those heat trapping greenhouse gas emissions, like carbon dioxide (CO2), come from cities.    

Much attention is paid to federal and provincial efforts to reduce greenhouse gas emissions like phasing-out coal generated electricity by 2030, the price on carbon pollution, and enacting an electric vehicle mandate, as these are big carbon reducing policies. Efforts at the municipal level can be overlooked despite having the potential to have a big impact in reducing greenhouse gas emissions. The United Nations’ Sustainable Development Goals identified Sustainable Cities and Communities as important in furthering climate action and justice. What tools do cities have at their disposal to reduce greenhouse gas emissions and what exactly makes a sustainable city?

What makes a city sustainable? 

There are several things that play a role in the sustainability of a city. Cities are at the forefront of the climate crisis in terms of mitigation and adaptation. Due to their smaller-scale, residents are able to consult their local government more readily than provincial and federal elected officials. Put succinctly, “Cities tend to experiment more. They don’t have as much political baggage … and are able to develop solutions that are more tailored and customizable to their communities.” As a result, cities have the potential to respond to local climate concerns more quickly than provincial or the federal government. Several areas where cities can influence climate mitigation and adaptation include but are not limited to transportation, land use, waste management, housing, and pollinator habitats. Here are some ways cities can become more sustainable!

Sustainable Transportation 

Transforming how we move around within our cities has the potential to significantly reduce carbon emissions.  Three quarters of Canadians live in a large urban area that have a population of more than 100,000 people. In addition, across Canada, 67.4% of people commute by themselves in their own personal automobile, the majority of which are still gas powered. Canadians’ transportation behaviours are a significant source of national CO2 emissions – approximately 22% come from the transportation sector, second only to the oil and gas sector. There is an opportunity for Canadian cities to implement sustainable transportation policies to limit the number of people driving and to lower CO2 emissions.

One of the best policies cities can implement to reduce their CO2 emissions is to encourage widespread use of active and public transportation in favour of private automobile transportation. Switching from the automobile to active travel is the best way for individuals to lower their mobility related CO2 emissions. One study found that “an average person who ‘shifted travel modes’ from car to bike decreased life cycle CO2 emissions by 3.2kgCO2/day,” and that “promoting active travel should be a cornerstone of strategies to meet net zero carbon targets.” If just 30% of people in a city of 100,000 switched to active modes of travel, based on this study, the daily CO2 reduction would be 93 tonnes or 35,000 tonnes, annually

Investing in public transportation so more people use the service instead of their car will likewise help to reduce emissions, improve air quality, and lower traffic congestion. Copenhagen is sometimes referred to as one of the world’s most sustainable cities, in part because they have invested in alternative methods of transportation. In Copenhagen, 63% of all trips made by residents are by walking or cycling with just 27% by car  

People biking and walking in a European city

The remainder of the car trips in a sustainable city are by electric vehicle. Cities can encourage the adoption of EVs by expanding public charging stations and increasing public awareness of them  

Land Use and Buildings   

Another tool in the city’s climate action belt is their ability to zone areas for specific land uses. Over the course of the 20th century, new developments in Canadian cities were primarily zoned for single-family detached houses. This type of development has led “urban sprawl” and pushed cities outwards taking over natural habitats and farmlands319 acres daily, the equivalent size of an average family farm in Ontario. Urban sprawl also induces demand for the private automobile as the long distances and low density makes transit and active transportation less attractive alternatives.

Instead, cities should focus on building more density and walkability through medium density zoning (think Montreal row houses and apartments) and mixed-use land development. By building things closer together, cities can save on infrastructure spending and their associated emissions as denser environments would require fewer water pipes, roads, and electricity lines. In addition, people will not have to travel as far for their daily activities thus reducing car travel and improving access to alternative modes of transportation. This is the central idea behind the “15-minute city”. 

How the buildings are built is another area with tremendous opportunity to improve the overall sustainability of a city. Green buildings can be built with energy efficiency in mind, be equipped with small-scale solar for energy generation, use sustainable materials and building practices, and reduce waste throughout the process.

The Bibliothèque du Boisé in Québec, for example, was built to the highest Leadership in Energy and Environmental Design (LEED) certification. Its sustainable design, building materials, and techniques make use of passive heating, natural light, and a vegetative roof to minimally disrupt the natural environment around it. The architect also made sure to plant 100 more trees to make up for those lost during construction!

An aerial image of houses and trees

The way cities are built plays a role in how they reduce their greenhouse gas emissions and become more resilient against the growing effects of climate change. Creating large greenspaces and greening the urban environment will reduce greenhouse gas emissions, improve air quality, and help to lower temperatures and mitigate the “urban heat island” effect. Urban heat islands occur when the majority of the surface area is covered in asphalt that absorbs and amplifies the heat from the sun and can be 5.6°C hotter than the air. This keeps cities warmer, particularly at night, preventing people from cooling down leading to heat exhaustion. In addition to greening urban spaces, another way cities can mitigate the heat island effect is to lower the surface area of dark asphalt by reducing surface parking.  

Trees are not the only flora that have a place in a sustainable city. Plants from a variety of native species play a diverse role in contributing to public health, biodiversity, storm water management, and food growth. Planting native species over imported monoculture species, such as the typical North American lawn, has several advantages. Prioritizing native species in urban green spaces will “form the foundation of healthy ecosystems,”. In addition, increasing the percentage of native species will contribute to climate change mitigation and adaptation – rain gardens are particularly adept at soaking up excess storm water.

Waste Management

How a city handles and limits the amount of waste it produces greatly contributes to sustainability today and for future generations. Diverting plastics, paper and cardboard, and organic waste from going to the landfill will lower greenhouse gas emissions and contribute to the circular economy. Instead of going to the landfill, recycled plastics can become clothes and building materials; composted food can be used for fertilizer to help feed people.

Cities all over the world have committed to strive towards being “zero waste” in the next couple of decades. In 2018, for example, the City of Vancouver introduced their “Zero Waste 2040” strategy and has already reduced the amount of waste going into the landfill by 36 per cent! The strategies Vancouver is employing are varied and include preventing food waste every step between the farm to table, composting inedible food or converting it into fuel, extending the lifetime of products and materials by repairing them, and reusing items before they are sent for recycling.


A sustainable city includes everything that has been discussed but it is also affordable for people to live in. Sustainability initiatives must be widespread throughout cities so that all residents benefit from them and not just those from wealthy areas. Sustainability initiatives not only reduce a city’s climate change impact, but they are also nicer places for people to live.

The Gaia Projects offers climate educational programming for every age group if you are interested in connecting the topic of sustainable cities for your students. At the elementary level, try out our Trash Tracker program so students can learn about waste diversion and how to properly sort garbage. In middle school, the Climate Labs program is offered in four different categories: waste, renewable energy, air quality, and energy consumption – each connects to sustainability in cities. Finally, at the high school level, the Climate Action Project presents students with the opportunity to explore low-carbon transportation and take action to reduce their own transportation emissions.

Author: Adam Mahoney, Program Coordinator, The Gaia Project


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