A new method for a city-wide life cycle assessment

Researcher at ESCI-UPF proposes a new method to assess and compare the environmental impacts of cities as a whole

Fostering city sustainability
Ontario city skyline. Photo: Pixabay.

With half the people living in cities today, assessing the environmental impact of urban areas is paramount. Jaume Albertí introduces new criteria to merge the City Prosperity Index - a 6 Dimensions indicator to measure the prosperity of cities- into life cycle assessment.

A PhD thesis recently defended by Jaume Albertí at the Universitat de Girona – awarded cum laude honours – claimed that, whatever a city is, it is the preferred choice for living nowadays. Albertí, a researcher of the UNESCO Chair in Life Cycle and Climate Change ESCI-UPF, showed his results on how to tackle a sustainability challenge unforeseen five thousand years ago, with the first cities known.

According to UN data, 55% of the world’s population is living in cities and roughly 70% will by 2050. The benefits of living close to each other are obvious: shorter transport lengths, better dissemination of knowledge, wider trade opportunities, to name a few.

But there are drawbacks either. With one in two people living in a city, the environmental impacts of urban areas are immense. The United Nations Human Settlements Program, UNHABITAT, reported in 2012 that cities use 78% of the world’s energy consumption and generate 60% of current global warming. Not a surprise, considering city dwellers are responsible for over 80% of the overall greenhouse gas (GHG) emissions in 2010, according to the World Bank.

The Chair intends to develop the Life Cycle Assessment (LCA) methodology for cities. LCA is a well-established method to assess potential environmental impacts for products and services and the gold standard to foster eco-design and eco-innovation. But cities are tricky sometimes. How can you tell today’s gigantic city boundaries? How would you allocate the impacts of satellite infrastructures, often in nearby smaller cities, such as airports and industrial areas?

Under the supervision of Dr Pere Fullana i Palmer, director of the Chair, and Dr Christian Brodhag, Director of research at the École des Mines de Saint-Étienne, Albertí proposes that the best methods to define city boundaries would be density-based for geographical limits and service-based for functional delimitation. The allocation problem, on the other hand, can be approached using a category-based procedure. To go deeper into these concepts, please read our former post “Aiming for truly sustainable cities”.

However, even sorting all the technical aspects out, the analysis would still be incomplete. Cities handle social aspects that regular LCA does not include. Luckily, UNHABITAT defines the City Prosperity Index (CPI) to cover their basic social dimensions in a measurable way. Would it be possible to merge LCA and CPI into a single indicator?

The answer is the new method for a city-wide LCA proposed by Albertí. A method with a clear definition of city boundaries, impact allocation procedures among cities and taking into account the relevant social and economic aspects of large communities.

Time will tell whether this approach can help put cities’ sustainability efforts into context, without shifting problems from environment to society or from one city to another, but hurry up: a side conclusion from Albertí’s work claims LCA analysis don’t last forever!

Tribunal Jaume Albertí

Left to right, Dr. Miquel Rovira (EURECAT), Dr. Miquel Casals (UPC), Dr. Jaume Albertí (ESCI-UPF), Dr. Marc Delgado-Aguilar (UdG), Dr. Pere Fullana i Palmer (ESCI-UPF) and Dr. Joan Vicente (UdG).

Further information and references

UN (2018). “68% of the world population projected to live in urban areas by 2050, says UN
Albertí, J. et al. (2017). “Towards life cycle sustainability assessment of cities. A review of background knowledge”. Science of the Total Environment, 609, 1049–1063.
Albertí, J. et al. (2018). “First steps in life cycle assessments of cities with a sustainability perspective: A proposal for goal, function, functional unit, and reference flow”. Science of the Total Environment, 646, 1516–1527.
Albertí, J. et al. (2019). “Allocation and system boundary in life cycle assessments of cities”. Habitat International, 83, 14-54.
Albertí, J. et al. (2019). “Does a life cycle assessment remain valid after 20 years? Scenario analysis with a bus stop study”. Resources Conservation and Recycling, 144 169-179.
Albertí, J. et al. (2019). “Life Cycle Assessment of a solar thermal system in Spain, eco-design alternatives and derived climate change scenarios at Spanish and Chinese National levels”. Sustainable Cities and Society, 47.

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