Synthesizing the evidence on green and blue infrastructure for urban temperature mitigation in Canada

Urban green and blue infrastructure (UGBI) is increasingly integrated into cities for its numerous benefits, particularly their cooling effects. As the body of evidence on UGBI cooling ability grows, systematic reviews are essential; however, Canadian studies have been notably absent from global reviews. This study synthesizes the evidence on UGBI cooling effect in Canadian cities, addressing gaps on cooler climates by examining the geographic, climatic, methodological, and UGBI-specific dimensions of the Canadian evidence. Following PRISMA guidelines, we retrieved 1,062 articles from Scopus and Web of Science, and after rigorous screening and data extraction, analyzed 43 studies using a systematic review approach. The results reveal a significant increase in studies over time, with a concentration on major cities such as Toronto, Vancouver, and Montreal. Central Canada overwhelmingly represents the evidence base. Most research was conducted in cold climate zones and primarily focused on green infrastructure elements, such as trees, vegetation, and green roofs, primarily focusing on their abundance rather than configurational or functional attributes. Thermal impacts were mainly measured through air temperature, land surface temperature, and energy savings, with cooling effects generally higher during the daytime. Among UGBI types, trees and parks exhibited the strongest cooling effects. Methodologically, simulation and observational approaches dominated, with a significant focus on micro-scale analyses. The review highlights important gaps, including the underrepresentation of smaller cities and regions such as Atlantic Canada, limited research on blue infrastructure, and minimal integration of health outcomes. Addressing these gaps is critical for developing robust guidelines to enhance urban resilience.