Climate change is here, and its effects are coming around faster than anticipated through more frequent extreme storms and unprecedented heatwaves.
Our temperatures have increased by an average of 1.2°C since the preindustrial era. Climate scientists have warned us that even a slight temperature increase of 1.5°C or 2°C can cause enormous and extraordinary turmoil.
Urban areas and cities are more vulnerable to climate change impacts due to the density of people and infrastructure. According to the United Nations, more than half of the world’s population lives in cities today and is expected to grow by another 2.5 billion by 2050.
How can cities build more resilience and combat the impacts of climate change?
The Insider article, “How investing in green infrastructure helps cities manage the effects of the climate crisis and creates healthy communities,” discusses how investing in green infrastructure is the key.
Building more green roofs, planting more trees and native plants, creating pockets of green spaces within the city, and converting abandoned industrial areas into parks, can help solve climate-related problems like storm flooding, pollution, and heatwaves while improving residents’ health and boosting local economies.
The benefits of green infrastructure to address climate change have led mayors from these cities worldwide to sign the C40 Urban Nature Declaration to show their commitment to green infrastructure.
Signatories include mayors from Austin, Athens, Barcelona, Berlin, Bogotá, Buenos Aires, Chennai, Copenhagen, Curitiba, Delhi, Durban, Freetown, Guadalajara, Haifa, Lima, London, Los Angeles, Medellín, Milan, Mumbai, New Orleans, Paris, Quezon City, Rio de Janeiro, Rome, Rotterdam, Salvador, San Francisco, Seattle, Stockholm, Sydney, Tel Aviv – Yafo, Tokyo.
These cities declare that “Nature in our cities serves as a natural buffer and regulator of climate impacts and protects urban residents and city infrastructure from extreme heat, flooding, drought, sea-level rise, and storms” (Urban Nature Declaration, 2022).
These mayors have committed to converting up to 40% of the city surface to green spaces like street trees, urban forests and parks, and permeable spaces like permeable pavements, infiltration trenches and applying regenerative urban agriculture, and providing equitable access to “green” and “blue” areas to 70% of its population, particularly to the most vulnerable. Cities are committing to achieve these targets by 2030.
The Insider article notes that green roofs can lower temperature by up to 4.4°C (40°F) and reduce the citywide temperature by about five degrees. Chicago leads in the construction of green roofs, with the city already installing more than 500 such roofs. San Francisco, New York, and Toronto also have ordinances that require green roofs for new and renovated buildings.
Green infrastructure reduces city temperatures, thus making cities resilient to UHI and heatwaves, encourages wildlife to flourish, improves water and air quality, and lessens stormwater runoff taking the pressure off grey infrastructures.
Parks and recreational spaces have economic benefits as well. It attracts more tourists, residents, and businesses in the area and increases property values.
The benefits of green infrastructure make it imperative for cities to incorporate them to address challenges and threats from climate change and rapid urbanization challenges and threats.
Increasingly green and blue infrastructure is being incorporated into broader whole-of-network and whole-of-ecosystem approaches. Green and blue infrastructure will need to be considered and included in wider infrastructure management plans and planning.
Milman, O., Witherspoon, A., Liu, R., & Chang, A. (2021, October 14). The climate disaster is here. The Guardian. Retrieved from https://www.theguardian.com/environment/ng-interactive/2021/oct/14/climate-change-happening-now-stats-graphs-maps-cop26
Rapid Urbanization Increases Climate Risk for Billions of People. (2017, July 13). United Nations Climate Change. Retrieved from https://unfccc.int/news/rapid-urbanization-increases-climate-risk-for-billions-of-people
Sweeney, E. (2022, April 1). How investing in green infrastructure helps cities manage the effects of the climate crisis and creates healthy communities. Retrieved from https://www.businessinsider.com/how-investing-green-infrastructure-manage-climate-change-2022-3
Urban Nature Declaration. (2022). Retrieved from https://www.c40.org/declarations/urban-nature-declaration/