Alexandre B. Hedjazi: Nature in the city can contribute to development and acceleration of urban resilience building
Cities contribute to more than 70% of global CO2 emissions while being highly vulnerable to climate change impacts. What nature-based solutions could help boost cities’ resilience?
One of the most common examples of NBS ( Nature Based Solutions) is expansion of urban vegetation (leafy tree planting, greening rooftops and facades or creating ecological corridors ).
Vegetation plays an important role in addressing many ecological challenges in Cities. From reducing the risk of Urban Heat Island to control Co2 and other pollutant emissions, vegetation can reduce daytime and nighttime temperature and filter air.
Urban Vegetation can also participate in reducing rain water run-off and facilitate the filtration of water to underground water (instead of finishing in the drains). Urban vegetation can also contribute positively in reducing noise pollution, improving the aesthetics of built areas as well as enabling the development of new recreation areas.
Nature in the city can contribute to development and acceleration of urban resilience building. While minimizing the impact of extreme weather events (flooding, drought, smog, heath wave etc.) it can also enhance the livability and inclusiveness of urban areas. A green leafy tree corridor that replaces street parking lanes of urban expressways contributes to improved air and water quality, enabled water filtration to underground water, enhanced biodiversity, increased resilience to climate change, and the provision of recreational spaces for communities. Converting some parking spaces into pedestrian areas with permeable pavement and soil can help with water harvesting and create opportunities for social interaction, outdoor seating, and the establishment of public spaces that enhance community engagement.
In a similar context, how can major urban centers come closer to green policies when it comes to housing, e.g. overheating, energy consumption in households, architectural design?
Among a plethora of authors Peter Calthrope in “The next American metropolis” (1993) devised simple interventions in some urban areas that can reduce the impact of higher temperature on buildings hence reducing the greater need for cooling as well as greater need for heating in winter time.
These interventions include where possible covering rooftops with PVC / solar panel reducing the impact of heath on the envelope of the building, facades and balconies. Natural ventilation, daylighting and biomass shading can be used extensively to restore natural cooling and heating dynamics and processes. Features such as porches, courtyards and overhangs can be added to the buildings to create buffer zones; narrower streets will reduce the energy use and loss, and encourage soft mobility.
Obviously these interventions need to be added to measures for greater energy efficiency (e.g. insulation) as well as sufficiency (e.g. reducing the heating temperature in winter to increasing the cooling temperature in summer) and consequently reducing energy use and consumption.
According to the UN Food and Agriculture Organization (FAO), 79% of global food production is consumed in far away urban areas. Are there ways to bring food production closer to people in the cities, especially considering that in mega capitals, such as Paris, Berlin or London, there is not enough space?
Introducing NBS in cities can optimize local food production while reducing the use of hinterland and open spaces in peripheries of the city leaving them to play their natural filtering and purification role. Introducing NBS in cities can optimize local food production and reduce the use of hinterland and drawing resources. This can be done through using private and public large buildings (e.g. schools, public buildings, shopping centers etc.) for rooftop food production. Food production can also be developed vertically in cities thanks to vertical farms and hydroponic farming techniques that reduce water usage by up to 90% compared to conventional soil-based farming.
The Forum of Mayors gather an ever-growing attention as a place to exchange good practices and build networks. How cities like Athens for instance could gain from this Forum and, to go one step further, how capitals of the European South faced with pressing climate challenges can build a bottom-up model of governance alongside state-led decision-makers?
Among a few other forums pioneering the exchange of best sustainability practices among cities and the building of collective knowledge, the Forum of Mayors serves as a platform for on-going exchange and mutual learning where mayors present their innovative solutions to the common challenges cities face across the globe.
Cities learn from each other’s best practices in creating climate-neutral cities, increasing urban resilience, gender mainstreaming, mitigating the effects of adverse weather events and actively engaging communities in policy-making and implementation.
Greek cities such as Athens by attending the Forum at the highest mayoral level accompanied by municipal senior experts in fields of priority can enable a virtuous circle of transfer of experience while promoting the Greek model of sustainable urban development. Participation at these fora will also provide Greek cities the opportunity not to commit some of the errors of their European peers hence saving public funds and time experimenting often imported models that are ill-adapted to various regions’ climate and environmental specificity.
Finally, participation at these fora also enable cities to use the platforms of international governance where states have had the final word to echo their concerns and visions of future through alliance building with other like-minded municipalities.
