Global multiregional input-output databases (GMRIOs) became the standard tool for tracking environmental impacts through global supply chains. To date, several GMRIOs are available, but the numerical results differ. This paper considers how GMRIOs can be made more robust and authoritative. We show that GMRIOs need detail in environmentally relevant sectors. On the basis of a review of earlier work, we conclude that the highest uncertainty in footprint analyses is caused by the environmental data used in a GMRIO, followed by the size of country measured in gross domestic product (GDP) as fraction of the global total, the structure of the national table, and only at the end the structure of trade. We suggest the following to enhance robustness of results. In the short term, we recommend using the Single country National Accounts Consistent footprint approach, that uses official data for extensions and the national table for the country in question, combined with embodiments in imports calculated using a GMRIO. In a time period of 2 to 3 years, we propose work on harmonized environmental data for water, carbon, materials, and land, and use the aggregated Organization for Economic Cooperation and Development (OECD) Inter-Country Input-Output GMRIO as default in combination with detailing procedures developed in, for example, the EXIOBASE and Eora projects. In the long term, solutions should be coordinated by the international organizations such as the United Nations (UN) Statistical Division, OECD, and Eurostat. This could ensure that when input-output tables and trade data of individual countries are combined, that the global totals are consistent and that bilateral trade asymmetries are resolved.

For developing product policy, insight into the environmental effects of products is required. But available life-cycle assessment studies (LCAs) are hardly comparable between different products and do not cover total consumption. Input-output analysis with environmental extensions (EEIOA) of full consumption is not available for the European Union. Available country studies have a low sector resolution and a limited number of environmental extensions. This study fills the gap between detailed LCA and low-resolution EEIOA, specifying the environmental effects of household consumption in the European Union, discerning nearly 500 sectors, while specifying a large number of environmental extensions. Added to the production sectors are a number of consumption activities with direct emissions, such as automobile driving, cooking and heating, and a number of post consumer waste management sectors. The data for Europe have been constructed by using the sparse available and coarse economic and environmental data on European countries and adding technological detail mainly based on data from the United States. A small number of products score high on environmental impact per Euro and also have a substantial share of overall consumer expenditure. Several meat and dairy products, household heating, and car driving thus have a large share of the total environmental impact. Due to their sales volume, however, products with a medium or low environmental score per Euro may also have a substantial impact. This is the case with bars and restaurants, clothing, residential construction, and even a service such as telecommunications. The limitations in real European data made heroic assumptions necessary to operationalize the model. One conclusion, therefore, is that provision of data in Europe urgently needs to be improved, at least to the level of sector detail currently available for the United States and Japan.