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19,668,000Yen (FY1998 13,796,000Yen)
Global Warming. Forest Sector. Wood Utilization, Carbon Sequestration, Housing, Recycling
A computer simulation model developed for the Japanese Forest Resource Basic Plan which is the basis of the Japanese forest policies is utilized to assess mitigation policies under the four scenarios. These are a) stabilizing timber supply at the present level (case 1); b) adopting long rotation (case 2); c) aggressively promoting domestic supply (case 3) and d) moderately promoting domestic supply (case 4). The results indicate case 1 and ease 2 contribute to storage carbon into the forest sector, and case 3 contributes to promote the development of the Japanese forest industry. Case 4 compromises both targets.
Newly built floor area in 1996 was divided into wooden and non-wooden structures, and tirnber input units per floor area were assumed as 0.2m3/m2 for wooden and as 0.04m3/m2 for non-wooden, Then new carbon stock in buildings became 6.52 Mt. Also the lost carbon stock was 1.92 Mt from the data of demolished floor area in 1996. Therefore the increase of building's carbon stock in 1996 was 4.6 Mt, and this amount of carbon was removed from the atmosphere.
Then calculation was done from data in 1997 on carbon quantity which would be input and fixed to construction sector from wood industry. The volume of timber was 24.88 Mm3, calculating from sold amount and processing yield on sawn timber, plywood, and wood composites. This carbon amount was 6.22 Mt, and it was near to 6.52 Mt as mentioned before.
From the data in 1991, wood waste, mainly demolition wood, of 18.23 Mm3 was burnt and buried uselessly, its carbon amount was 4,56 Mt,
Wood composites, particle board etc., has great significance in material recycle of demolition wood. In 1997, used timber ratio as raw material of particle board was 40%, and its ratio is supposed to higher in future.