Evaluating the carbon footprint of a Spanish city through environmentally extended input output analysis and comparison with life cycle assessment

Manuel Rama; Eduardo Entrena-Barbero; Ana Cláudia Dias; María Teresa Moreira; Gumersindo Feijoo; Sara González-García

doi:10.1016/j.scitotenv.2020.143133

Evaluating the carbon footprint of a Spanish city through environmentally extended input output analysis and comparison with life cycle assessment

Sci Total Environ. 2021 Mar 25:762:143133. doi: 10.1016/j.scitotenv.2020.143133. Epub 2020 Oct 16.

Authors

Manuel Rama¹, Eduardo Entrena-Barbero², Ana Cláudia Dias³, María Teresa Moreira², Gumersindo Feijoo², Sara González-García²

Affiliations

¹ CRETUS Institute, Department of Chemical Engineering, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain. Electronic address: m.rama@usc.es.
² CRETUS Institute, Department of Chemical Engineering, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
³ Center for Environmental and Marine Studies (CESAM) & Department of Environmental and Planning, University of Aveiro, Portugal.

PMID: 33121788
DOI: 10.1016/j.scitotenv.2020.143133

Abstract

Currently, most of the greenhouse gas (GHG) emissions are attributed to cities, as they are the global centers of business, residential and cultural activity, cities are expected to play a leading role in proposing climate change mitigation actions. To do so, it is important to have tools that allow the carbon footprint of cities to be assessed as accurately as possible. This study aims to quantify the carbon footprint (CF) associated with the activities developed in a Spanish city (Cadiz, Southwest Spain) by means of two available environmental methodologies, namely Environmentally Extended Input-Output Analysis (EEIOA) and Life Cycle assessment (LCA). When EEIOA is considered, two downscaling factors were proposed for the analysis due to the nature of the data handled (monetary data), based on the incomes (DF₁) and expenditures (DF₂) per inhabitant at city level. Regarding LCA, the rates of consumption of goods and production of waste per inhabitant have been processed to estimate the CF. The CF scores identified were 5.25 and 3.83 tCO₂-eq·inhabitant^-1·year^-1 for DF₁ and DF₂ respectively, according to EEIOA, and 5.43 tCO₂-eq·inhabitant^-1·year^-1, considering LCA. Therefore, a similarity can be concluded between the results obtained with both methodologies despite the inherent differences. Considering the results, the downscaling procedure based on income per inhabitant should be preferred, pointing to EEIOA as a good alternative to LCA for evaluating the CF at city level, requiring less time and effort. In contrast, EEIOA reports more limitations when critical flows were identified, which LCA can solve. Finally, this study can be of great interest to policy makers and city governments to know the CF and the main flows that contribute and in this way, can develop new policies and city models for reducing GHG emission new policies and city models for reducing GHG emission and addressing climate change.

Keywords: Greenhouse gas emissions; Spain; Sustainable city; Urban environmental management; Urban metabolism.