3 2 IPCC SRES 2.1 1 2000 3 15 IPCC 1990 1992 IPCC 8 IPCC 1992 Houghton et al, 1992 IS92a IPCC 1992 a 6 1985 1990 1990 1992 1994 IPCC Alcamo et al, 1994 IPCC 1996 IPCC IPCC 3 IPCC IPCC 3 3 IPCC 4 ”Special Report on Emission Scenarios” SRES SRES 2 SRES SRES 5 Morita and Lee, 1997 170 400 2100 190 2.1 SRES Global Carbon Dioxide Emissions (index, 1990=1) 0 2 4 6 8 10 1900 2000 2100 Median 25% 5% 75% 9