Politécnica de Madrid

What impact do our consumption habits have on the environment?

UPM researchers conclude that the impact of Madrid on the climate change is much greater than the impact shown in its inventory of greenhouse gas emissions.

This is the conclusion of the results obtained from the new methodology used for the emission accounting that includes the entire life cycle of goods and services

A study carried out by researchers from Universidad Politécnica de Madrid (UPM) in collaboration with Universidade Federal da Bahia (Brazil), has addressed the challenge of adopting a new methodology of greenhouse gas emissions accounting in large cities. This new accounting system is more precise since it includes not only the emissions associated with the production of products and services but also their consumption.

Making cities more sustainable is one of the most vital challenges of modern times. According to the World Bank data, the urban population in 2016 accounted for 54.3% of the total global population. Satisfying the growing demand of products and service by the citizens requires an increase not only of their productive activity but also the transport and distribution of the products that are produced all around the world and are consumed in a certain city.

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Therefore, the assessment of climate change impact on cities (its carbon footprint) cannot be limited to the accounting of greenhouse gas emissions associated with productive activities that take place within their geographical limits. According to Javier Pérez, a researcher from the group of Environmental Technologies and Industrial Resources at UPM, “it is necessary to go further; we have to integrate both production and consumption in the accounting systems”.

The greenhouse gas emissions inventory in Madrid, as in most of the cities in the world, has been historically based on emissions associated exclusively with productive activities. In order to improve the quality of these inventories, researchers have assessed the challenge that the city of Madrid faces when it comes to implementing a consumption-based accounting methodology, that is, a methodology that estimates the emissions associated to supply chains and thus obtaining the impact associated to the final consumption of goods and services.  

This analysis was carried out taking as an example the city of London, a city that has developed a procedure of implementation of this type of methodology.

According to the traditional inventory of emissions between 2010 and 2015, the emission per capita of the citizens of Madrid was between 3.5 and 4 tons of CO2 equivalent per inhabitant per year. Considering the results obtained by the research team, implementing a consumption-based accounting system rather than based on production, the emissions per capita would double. This means that the current impact on climate change of the city of Madrid is underestimated.

Therefore, it seems necessary to implement these new accounting systems that allow us to accurately assess the impact caused by goods and services consumed by citizens considering the whole life cycle. This data would be helpful for decision-makers who develop and advice on environmental policy.
Researchers conclude, “If we achieve that cities adopt these accounting methodologies, citizens would be aware of their real impact and we would be able to take decisions to stop these emissions”.


Implementing city-level carbon accounting: A comparison between Madrid and London. José Celio Silveira Andrade, Andrea Dameno, Javier Pérez, Juan Manuel de Andrés, Julio Lumbreras. Journal of Cleaner Production, 172 (2018), 795-804.