Climate change in cities and the role of urban planning and natural based solutions
2023, Feb 1°. The conference is part of the public events of USAGE held in Ferrara (Italy), one of the pilot cities. It was addressed to citizens and NGOs, teachers and students of high schools and universities, academia, businesses, and environmental practitioners as an opportunity to share the vision and the goals of the project.
Councillor Alessandro Balboni (responsible for environmental policies at the city level) discussed with senior researchers and scientists. He stressed the presence of the audience in the hall as an indicator of the perceived importance of environmental issues.
Carlo Cacciamani (climatologist) illustrated the oscillating behavior of CO2 in the last 800,000 years: a rapid acceleration due to anthropogenic causes, such as global warming from 1850 to 2021. So it developed simulations based on CO2 input (or, conversely, input mitigation) scenarios. The IPCC, which predicted so many of the risks that are occurring, provides information to scientists and policymakers with its reports. These risks (heat stress, water scarcity, food security, flooding) have a huge impact on social security. In the Mediterranean area, the scenarios are quite serious: the reduction of river runoff (the Po River from 1,000 m3/sec went to 180 mc/sec) and the increase of temperature in Italy and the Emilia-Romagna Region (measuring stations located outside urban areas) have caused precipitation that has shaken the hydroclimatic balance. More evapotranspiration than precipitation has been recorded. That is why, Cacciamani argues, adaptation policies must be interpreted under the framework of resilience. They are also capable of creating new opportunities!
Elena Farnè (architect, expert in urban regeneration) brings the example of Medicina, a small Italian municipality, which applies the concepts expressed in the guidelines and applied in big cities such as Copenhagen. Urban policies in Medicina started from the citizens' need to environmentally and socially re-planning the city, engaging people to back to degraded spaces. She stressed the importance of bringing knowledge: building multidisciplinary teams with agronomists, hydraulic engineers, and architects.
Giovanni Morelli (agronomist, expert in urban green) Wrong anthropocentric view. Trees as providers of ecosystem services, but trees are living beings with their own needs and constraints. Need to foresee how many trees will survive, and not how many trees will be planted. Three words characterising a tree: sedentary, long life, transgenerational. Need to guarantee water needed by trees. Minimum threshold for the effectiveness of planting trees in urban areas. The 3-30-300 Progam. Analysis of tree stability.
Luisa Ravanello (researcher at ARPAE on communication and training courses, public spaces, and climate adaptation) talked about guidelines and case studies to free the soil with a focus on communicating content. Ecosystem services, mainly regulation services (of runoff, heat, etc.) and cultural services, production services. The role of trees: decreasing air temperature, if planted in such a way that there is shadow continuity. Health impacts of heat waves: morbidity, mortality, pre-deceases. This means that there is the higher vulnerability in urban areas, without urban runoff. Characteristics of nature-based solutions for adaptation to urban climate change: interdisciplinarity, multi-objectives, need of integration among planning tools. "Sponge city", "oasis city", "city for people" are metaphors for the results/objectives of urban transformation. Example: Copenhagen (Osterbro district).
Michele Munafò (senior researcher at ISPRA on soil consumption and urban planning) said we are doing the opposite of what we should be doing, especially when we look at soil consumption. Construction of new buildings, new infrastructure, logistics, grounded photovoltaics are eroding soil fertility. There is also a dangerous link between soil consumption and the real estate market. One-third of homes are unoccupied. While there is no link between soil consumption and population growth.
What we know is that we need to transform plans into actions!
Teodoro Georgiadis (senior researcher at CNR-IBE on biometeorology and bioeconomy). It is very important to run software to design and co-design urban policies. Thanks to new technologies, we can start from the analysis of heat islands, and thus from the knowledge of critical issues, identify the most suitable solutions to improve citizens' comfort, especially through nature-based solutions. Georgiadis emphasized the importance of data, without which everything discussed is mere opinion.