The creation of a Global Urban Metabolism Database: Method and challenges for consolidating urban metabolism studies into a standardized, open access database

Urban metabolism studies vary widely in terms of scope, methodology, choice of indicators, and research aims. Their results are published in a variety of formats such as scientific papers, administrative reports, or technical... [ view full abstract ]

Urban metabolism studies vary widely in terms of scope, methodology, choice of indicators, and research aims. Their results are published in a variety of formats such as scientific papers, administrative reports, or technical publications. This variety of scopes and formats makes it difficult to compare urban metabolism studies and identify global urban metabolic patterns. The creation of an online and open source global urban metabolism database in which a great number of urban metabolism studies are collected and analyzed allows to examine whether there are any patterns and trends in urban resource use, waste generation and pollution across the globe. The aforementioned database will enable stakeholders to find metabolic data for their city and compare it with all the other case studies for which data is available (for the same metabolic flow, year, region, etc.) in order to put it in perspective and contrast data across cities.

To set up this global urban metabolism database, relevant scientific publications were first identified manually as well as through an automated scraping of indexes and search engine results. Metabolic flow indicators and results were then manually extracted. This process resulted in an extensive list of metabolic flow indicators and a database of raw data from different urban metabolism studies. Each data point was indexed with the original publication, the geographic area and the year of study in order to enhance comparability and traceability. To validate the database after having extracted the data, the authors of the different publications were e-mailed and invited to review the numbers and to add additional data from other studies or publications. In order to facilitate the use of the data by other urban metabolism researchers, all the numbers were made publicly available and presented in several different formats including machine-readable on line data tables and graphs, as well as separate spreadsheets and customizable reports.

Since different urban metabolism studies pursue different aims and are dependent on data availability, they tend to use different urban metabolism indicators. This contributed to the challenges that were encountered when the information from such a broad number of sources was consolidated to set up the global database. By presenting the lessons learned from this exercise, valuable insights about how urban metabolism studies could become more comparable are outlined, and insights for the future application of the various methodologies are presented.

To conclude, the numerous benefits and uses of such a global urban metabolism database are emphasized by presenting the results of a preliminary analysis of the data, which aims at identifying patterns in resource use and pollution emissions through different data visualizations and analytical tools developed in parallel to the database. By contrasting metabolic indicators to different socioeconomic variables, information on potential drivers of the material consumption of cities can be gained.