A global standard method for measuring environmental loads in administrative divisions has not been officially established for environmental accounting at the local government level. As a consequence, environmental accounting has not been adopted by local governments as widely as private companies around the world.
Life cycle impact assessment (LCIA) is one aspect of research in the field of life-cycle assessment, whereby environmental loads throughout the life cycle of products and services are measured in a quantitative way. Research in which environmental loads are determined according to geographical location has become more and more important. This study therefore focused on administrative divisions in 42 countries, most of which are OECD members, and attempted to quantify the annual environmental loads emitted within each division in the year 2015, using the global-scale LCIA method. For this, this study leveraged the assessment theory Life-Cycle Impact Assessment Method Based on Endpoint Modeling 3 (LIME3). This method is able to calculate assessment results in monetary units while integrating the environmental loads of several impact categories, such as climate change and land use, based on environmental conditions and environmental science.
Using statistical information that was reliable, verifiable, and comparable, this study calculated environmental loads in administrative divisions in 42 countries. The total environmental damage amount for the 42 countries was calculated to be 5.22 trillion USD. The top five amounts were land use (1.76 trillion USD), water consumption (1.36 trillion USD), forest resource consumption (0.70 trillion USD), climate change (0.52 trillion USD), and fossil fuel consumption (0.50 trillion USD). When the damage amounts were divided by the area or population of each division, the average amount per unit area for all Territorial level 2 (TL2) regions was calculated to be 67,300 USD/km2 (area-weighted average), and the average of amount per capita was calculated 1,250 USD/capita (population-weighted average). These damage amounts per unit area and per capita were placed on a world map according to impact category to visualize the regionality of environmental loads worldwide. The amount per unit area for most categories showed a trend similar to population distribution around the world, and the values for land use also showed a trend indicative of local agricultural activity in some countries. In particular, the amount per capita for climate change as well as the total of all categories showed a contrasting trend to the amount per unit area, and the value tended to be relatively lower in densely populated areas around the world.
The variation coefficient for the damage amounts per unit area and per capita was calculated for each region in order to statistically capture the disparities of environmental loads according to impact category. The disparities of environmental loads that were deeply related to housing, such as climate change and waste, tended to be narrow among TL2 regions worldwide. From these results, this study revealed environmental impacts around the world from the perspective of several categories, thus providing information useful for making decisions about international environmental policies.
