Every city in the world is vulnerable to the impacts caused by different "shocks" and tensions, both of natural or human origin. Nowadays, cities and their inhabitants face additional and amplified challenges as a result of the rapid urbanization, climate change, and political instability.

Taking into account that 50% of the population already lives in cities and that, by 2050, this figure is expected to reach 70%, there is an urgent need for new tools and approaches that strengthen local administrations and citizens, as well as their capacity to face unexpected challenges and to better protect human, economical and natural assets of our towns and cities.

Resilience refers to the ability of any urban system to maintain continuity and relative normality after suffering any type of external impact, adapting positively and transforming towards sustainability. Therefore, a resilient city is one that assesses, plans and acts to prepare for and respond to all hazards, whether sudden or slow onset, expected or unexpected. By doing so, cities are better prepared to protect and improve people's lives, to secure progress in development, to foster a conducive environment and to drive positive change.

As both the risks and the urban population are drastically increasing, the concept of resilience has risen high on the international agenda. This is especially relevant due to the fact that the poorest and most vulnerable groups are the most likely to suffer the consequences of said shocks and tensions, without having the resources to recover. Therefore, the cities that understand resilience as a key target or concept are those committed to a sustainable future and without leaving anyone behind.

During 2019 we worked together with the municipalities of the cities of Maputo (Mozambique), Asunción (Paraguay) and Barcelona (Spain) to document the challenges and tensions faced by three very different towns.

The challenges for the city of Barcelona are sustainable demographic growth and more efficient care for the elderly –typical of a highly developed city. This contrasts starkly with the challenges for the municipality of Maputo, mainly vulnerable to the impacts of climate change. Currently, record temperatures, internal flooding, pluvial erosion and coastal erosion due to the dynamics of sea waves, can be observed. In 2010 the city was identified as one of the places most at risk of suffering the consequences of climate change by the World Bank and the INGC (National Disasters Management Institute of Mozambique).

Asunción, on the other hand, must urgently deal with the contamination of the city’s water supply, which is the result of flooding processes, the absence of appropriate wastewater treatment and the lack of adequate disposal of solid waste. The city’s two principal actions are reinforcing the containment of rivers to protect the city, and the construction of a drainage system for rain and wastewater.

The Urban Resilience project was created with the aim of better transmitting what the concept of resilience consists of when applied to urban areas. The results have been used by the United Nations and the European Commission to communicate on this matter. In 2020, and on the occasion of the World Urban Forum 10, the documentary was screened in front of those attending the summit in the city of Abu Dhabi.

The ultimate aim of the project, led by the Department of Habitat of the United Nations, is to contribute in weaving an information network through which all the involved cities of the resilience program can learn from each other about how to deal with present and future challenges.