Characteristics of urban and state emission inventories—a comparison of examples from Europe and the United States

Emission inventories are a valuable tool used in carrying out environmental impact assessments. Inventories may be constructed on a range of scales and can hence cover individual urban areas, contries or continental scales. The objective of this paper is to highlight major differences between the characteristics of various urban and national emission inventories. Data for the year 1990 has been used to compare inventories for London, Berlin, New York and Los Angeles as well as national inventories for the UK, Germany and USA. A valid comparison of emission data from various locations can only be carried out if a common basis is used for categorisation, and for the purpose of this work all urban and national emission inventory data have been converted to the CORINAIR SNAP90 nomenclature. Differences between the inventories reflect not only true differences in emissions, but also distinctions which are related to the way in which the inventory has been produced, especially which emission sources the main efforts have been concentrated upon. This paper suggests that further harmonisation of existing emission inventories is highly desirable. An advance could be achieved if each agency responsible were to present their emission inventory results, besides their own specific categorisation, also in a common emission nomenclature like CORINAIR-SNAP.