Mapping Amplification Pathways of Urban Nature-Based Climate Solutions: Empirical Insights from Canadian Case Studies
This paper employs a mixed-methods comparative case study of two Canadian cities to map the non-linear, multidimensional pathways through which urban nature-based climate solutions are amplified over time, proposing an expanded typology that includes "enriching" to better capture the diversity and quality of their co-benefits.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Cities are increasingly on the front lines of a converging crisis. As global temperatures rise, biodiversity fades, and social inequalities widen, urban areas face a "polycrisis" where these challenges compound one another. In response, planners and policymakers have turned to nature-based solutions. These are not merely decorative parks or isolated gardens, but active strategies that use natural systems—like wetlands, forests, and green roofs—to solve multiple problems at once. They can cool a neighborhood, absorb floodwaters, store carbon, and provide space for community gathering. However, a persistent problem remains: many of these projects start as small, isolated experiments. They flourish in a single neighborhood or a pilot site but often fail to grow into city-wide transformations. The critical question for the future is not just how to build these solutions, but how to amplify them—how to take a successful local idea and expand its reach, depth, and impact so it changes the entire urban system.
A team of researchers from the University of Waterloo set out to understand exactly how this amplification happens in the real world. They focused their study on two major Canadian cities, Vancouver and Halifax, both recognized as leaders in climate action but with different government structures and histories. The researchers interviewed twenty key people involved in these projects, from city planners and non-profit leaders to community organizers, and reviewed a wide range of official documents. They were looking for the specific pathways that allowed nature-based projects to move beyond their origins. Instead of simply counting how many trees were planted or how many gardens were built, they mapped the journey of five distinct initiatives: green infrastructure in Vancouver, naturalization efforts in Halifax, shoreline restoration, urban community gardening, and urban forestry programs. Their goal was to trace the connections between people, policies, and places that allowed these projects to grow stronger and reach further.
The study reveals that amplification is rarely a straight line. It is a complex, multidimensional process that happens in three distinct ways. First, projects can amplify "within," meaning they become more stable, faster, or longer-lasting in their original location. Second, they can amplify "out," spreading to new neighborhoods, different types of buildings, or even other cities. Third, they can amplify "beyond," changing the rules, values, and norms of the society around them, such as by shifting how a city thinks about land use or by empowering communities to take ownership. The researchers found that these three directions often happen at the same time or in sequence, driven by partnerships between different groups. For instance, a project might start as a small garden, then grow into a city-wide policy, and finally shift the cultural understanding of what a neighborhood should look like.
One of the most significant findings of the research is the discovery of a fourth dimension the team calls "enriching." While existing frameworks focused on how big a project gets or how far it spreads, this new concept looks at the quality and diversity of the benefits a project provides. A project can become "enriched" if it starts offering more types of value to the community, such as combining flood protection with education programs or social cohesion. The researchers observed this in Halifax, where a community garden evolved from a simple plot of land into a hub for youth education, food security, and cultural exchange. The addition of a greenhouse and STEM programs didn't just make the garden bigger; it made the impact deeper and more diverse. Conversely, the study also identified "de-enriching," where a project loses value. In Vancouver, a change in building codes meant that while rainwater management rules were applied to more buildings, the specific requirement to use vegetative solutions like rain gardens was relaxed in favor of simpler underground tanks. This sped up construction but reduced the ecological and social benefits that the plants would have provided.
The research also highlights that amplification is deeply political and relational. It does not happen automatically; it requires active collaboration. In Vancouver, the success of green infrastructure relied on partnerships between the city's engineering department, parks board, and local non-profits. In Halifax, the "Naturalization" strategy, which replaces manicured lawns with native plants, succeeded because it engaged residents to steward their own properties and worked with schools to teach children about local ecosystems. The study shows that when different sectors—government, business, non-profits, and community members—work together, they create a network of support that allows projects to survive and thrive. However, the researchers also noted a significant gap in their own work: they were unable to include substantial input from Indigenous communities, despite the fact that Indigenous knowledge is central to many of these initiatives. They acknowledge that true amplification in Canada must involve reciprocal partnerships with Indigenous peoples, a step that requires resources and time they did not have for this specific study.
Ultimately, the paper suggests that for nature-based solutions to truly transform cities, we must stop viewing them as static objects and start seeing them as dynamic processes. A successful project is not just a tree or a garden; it is a web of relationships, policies, and evolving values. The researchers found that when these projects are allowed to grow in multiple directions—becoming more stable, spreading wider, changing norms, and offering richer benefits—they can help cities navigate the complex challenges of the future. The study does not claim to have solved the problem of climate adaptation, but it provides a clear map of how successful initiatives move from the margins to the mainstream. By understanding these pathways, cities can better support the projects that have the potential to create resilient, just, and thriving urban environments for everyone.
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