Urban greenery: Can urban green infrastructure become the backbone of the city of the future? An experiment on two cities: Turin and Medellin

The development of the cities is a phenomenon nowadays reflected in several cases of growth or decline that respond to different social, political, economic, and landscape contexts. In the case of growing cities, we can analyze the cities of Bogotá, Medellín, Lima, and New York, which began as small cities and suffered precipitous growth that continues to increase in density and surface area. In the shrinking cities, there is evidence of the fracturing of spaces due to the abandonment of areas called non-places, as in the case of Paris, Rome, or Turin, where a growth peak has already begun to decrease or, in some cases, remains above average. In both cases, a loss of identity happened: The modification of urban space can generate a loss of collective memory around the cultural and environmental/natural heritage. Therefore, the research aims to understand the different causes and reactions of these urban phenomena to propose urban strategic lines for each scenario where green becomes the axis of urban restructuring. To understand the above, we will develop a comparative analysis between Turin and Medellín: Turin (Italy) is a city in decline, rigidly planned and with a punctual destination of uses. Thus, today presents a fracture caused by abandoned spaces that generate environmental, social, cultural, and urban fractures. Medellín (Colombia), on the other hand, is a city that has grown in an emergent and accelerated manner, involving the emergence of particular environmental, social, cultural, and urban conditions. However, the two cities present a similar population, the presence of the river as a generator and structuring axis, and they are both surrounded by greenery vastly diminished by the creation of urban spaces, as well as deficient spaces along the rivers generating a disconnection between the population and the natural structure. For the above reason, and under a contemporary city context, we want to highlight the importance of green as an element of restoration at an environmental level and as a physical-spatial unifier. We will work on greenery as a crucial issue to understand natural and cultural heritage. We will consider the demands brought along by the problems related to drastic changes in heat due to climate change, the loss of the natural structure within cities and heat islands, and the increase of CO2. From the historical, environmental, social, and cultural analysis, conclusions focused on how cities have behaved concerning greenery and their growth. We propose two strategic plans for each city (Turin and Medellin) where strategies of controlled growth are presented more harmoniously with the green and its cultural implications and a strategic plan using the green for the abandoned spaces, creating cohesive and communitarian spaces. Therefore, we decided to carry out two types of intervention, which follow the same strategies of reinsertion on the green but with different methodologies considering the character and context.