The Tanikawa Laboratory at Nagoya University is attempting to estimate and evaluate the weight of human activity since 1998, and particularly to elucidate how much material has been used in industrial processes. The physical weight of industrial life is reflected in buildings, roads, cars, furniture and other durable materials which provide services we need. Reducing accumulated weight and improving efficiency by weight are vital in achieving a more sustainable society. The Tanikawa Laboratory focuses on Multi-scale Material Stock Analysis with regard to heavy anthropogenic disturbance, on national, regional and city scales.
City-scale material stock analysis is especially relevant to our everyday lives. People can see how much material supports their lives, and city planners can recognise which areas have bigger metabolism. The Tanikawa Lab has used 4D-GIS (four dimensional geographical information systems) to analyse material stocks and local metabolism (Tanikawa and Hashimoto, 2009). This study clarified material accumulation by vertical location, such as above and below ground, from the viewpoint of recyclability. By estimating the demolition curve, the life span of buildings in an urban area was found to be shorter than the national averages in both Japan and the UK. This paper also showed that in the Wakayama City centre in Japan in 2004, 47% of total construction material was stocked in underground infrastructure.
On the other hand, developing countries need to consume more materials to keep improving their people's quality of life. This is leading to increased energy and material flows, and GHG emissions. Material stock analyses are also being performed for developing countries, especially China (i.e. Feng Shi et al., 2012). The Tanikawa Lab discusses possibilities for ‘dematerialization’ and ‘decarbonization’ in developing countries. The researchers forecast future steel and cement demand and related resource consumption and CO2 emissions for building and transportation infrastructure, based on a material flow analysis of China.
Furthermore, material stock and flow analysis is also useful for understanding disasters which seriously damage cities, such as the earthquake in Japan that occurred on 11 March 2011. Estimated material stocks include volumes of accumulated materials in cities, so material stocks in damaged areas are similar to the volume of rubble which needs treatment and transfer. Volumes of material stocks in damaged areas indicate the quantities of material necessary to reconstruct areas, to enable a return to previous levels of local human activity.
H Tanikawa and S Hashimoto (2009) Urban stock over time: spatial material stock analysis using 4d-GIS, Building Research & Information, Volume 37, Issues 5 & 6, Pages 483–502, 2009.
Feng Shi, Tao Huang, Hiroki Tanikawa, Ji Han, Seiji Hashimoto, and Yuichi Moriguchi (2012) Toward a Low Carbon Dematerialization Society: Measuring the Materials Demand and CO2 Emissions of Building and Transport Infrastructure Construction in China, Journal of Industrial Ecology, Vol. 16, No 4, August, 2012.