ୡ⏺ࡢ㎰ᆅ࣭ᯘᆅ㟂せࡑࡢᢚไ࣏ࢸࣥࢩࣕࣝ
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ୡ⏺ࡢࣂ࣐࢜ࢫ㈨※㟂せ㔞ࡢቑຍࡣ㸪ᅵᆅ⏝ࡢኚࢆࡶࡓࡽࡋ㸪ࡑࡢኚࡣᵝࠎ࡞ࣉࣛࢿࢱ࣮ࣜࣂ
࢘ࣥࢲ࣮ࣜᙳ㡪ࢆ࠼ࡿ㸬ࣂ࣐࢜ࢫ㈨※㟂せࡀࡶࡓࡽࡍࡇࢀࡽࡢᙳ㡪ࢆ᫂ࡽࡍࡿࡇࡣ㸪ᑗ᮶ࡢ ᣢ⥆ྍ⬟࡞ࣂ࣐࢜ࢫ㈨※ࡢ⏝ࢆ᳨ウࡍࡿୖ࡛㔜せ࡛࠶ࡿ㸬ᮏ◊✲࡛ࡣ㸪ᑗ᮶ࡢ㣗ᩱ࣭ࣂ࢜⇞ᩱ࣭∾
ⲡ࠾ࡼࡧᮌᮦࡢ㟂せ㔞ࢆ᥎ィࡋ㸪ࡑࡢ⏕⏘ᚲせ࡞㎰ᆅ࣭ᯘᆅࡢ᥎ィࡑࡢ๐ῶ࣏ࢸࣥࢩࣕࣝࡘ࠸᳨࡚
ウࢆ⾜ࡗࡓ㸬ࡑࡢ⤖ᯝ㸪㎰ᆅ㠃✚ࡣ࡛᭱4.5 Ghaᚲせ࡞ࡿ᥎ィࡉࢀ㸪せᣑ㎰ᆅ㠃✚ࡣ㸪᭱576 Mha࡛࠶ࡗࡓ㸬ࡲࡓ㸪ᑗ᮶ࡢᯘᆅ㠃✚㟂せ㔞ࡣ࡛᭱4.6 Gha࡞ࡾ㸪2010ᖺࡢᐇ㝿ࡢᯘᆅ㠃✚ࢆୖᅇࡿ⤖
ᯝ࡞ࡗࡓ㸬⫗㣗ࡢ๐ῶࡸ㣗ရᗫᲠ≀ࡢ๐ῶࡼࡗ࡚㎰ᆅ㟂せࡣ࠶ࡿ⛬ᗘ๐ῶ࡛ࡁࡿࡶࡢࡢ㸪ᅵᆅ⏝ࢆ
ᣢ⥆ྍ⬟࡞ࡶࡢࡍࡿࡓࡵࡣ㸪ᮌᮦ㟂せࡢ๐ῶࡘ࠸࡚᭦᳨ウࡍࡿᚲせࡀ࠶ࡿ㸬
Key Words : SSPs(Shared Sociecinomic Pathways), biomass, land use, Planetary Boundaries
1. ࡣࡌࡵ
ୡ⏺ࡢࣂ࣐࢜ࢫ㈨※㟂せ㔞ࡢቑຍࡣ㸪㎰ᆅࡸᯘᆅࡢ 㟂せࢆቑࡉࡏ㸪ࡑࢀࡀᅵᆅ⏝ࡢኚࢆࡶࡓࡽࡋ㸪⏕
≀ከᵝᛶࡢῶᑡ㸪❅⣲࣭ࣜࣥࡢὶฟ㸪ῐỈࡢ⏝㸪Ẽೃ
ኚື➼ࡢᵝࠎ࡞ࣉࣛࢿࢱ࣮ࣜࣂ࢘ࣥࢲ࣮ࣜ1)ᙳ㡪ࢆ
࠼ࡿ㸬ࣂ࣐࢜ࢫ㈨※㟂せࡀࡶࡓࡽࡍࡇࢀࡽࡢᙳ㡪ࢆ᫂
ࡽࡍࡿࡇࡣ㸪ᑗ᮶ࡢᣢ⥆ྍ⬟࡞ࣂ࣐࢜ࢫ㈨※ࡢ
⏝ࢆ᳨ウࡍࡿୖ࡛㔜せ࡛࠶ࡿ㸬➹⪅ࡽࡣ㸪ࡇࢀࡲ࡛㸪 㣗ᩱ࣭ࣂ࢜⇞ᩱ㛵ࢃࡿᑗ᮶ࡢ㎰ᆅ㠃✚ࡢ㟂せ㔞ࡢ᥎ ィࢆ⾜ࡗࡓ㸬ࡑࡢ⤖ᯝ㸪2010ᖺࡽࡢせᣑ㎰ᆅ㠃✚ࡣ 2100ᖺࡲ࡛࡛᭱400Mha࡞ࡾ㸪ࣉࣛࢿࢱ࣮ࣜࣂ࢘ࣥ
ࢲ࣮ࣜࢆ⬣ࡍ್࡞ࡗࡓ2)㸬
ࡋࡋ࡞ࡀࡽ㸪ୖグ᳨࡛ウࡋ࡚࠸ࡿ㎰ᆅ㠃✚ࡣ㸪స≀
⏕⏘ࡢࡓࡵࡢ⪔సᆅ㠃✚ࡢࡳࢆᣦࡋ㸪∾ⲡᆅࡘ࠸࡚ࡣ
⪃៖ࡋ࡚࠸࡞࠸㸬2010ᖺ⌧ᅾ㸪ୡ⏺ࡢ㎰ᆅࡢ࠾ࡼࡑ7
ࢆ∾ⲡᆅࡀ༨ࡵ3)㸪ᚋࡶ㸪⤒῭ᡂ㛗ࡶ࡞࠺㣗⏕ά ࡢኚࡼࡾ␆⏘≀ࡢ㟂せቑຍࡀணࡉࢀࡿࡇࡽ㸪
∾ⲡᆅࢆྵࡵࡓ㎰ᆅ㠃✚㟂せ㔞ࡣࡉࡽࡁࡃ࡞ࡿ⪃
࠼ࡽࢀࡿ㸬ࡲࡓ㸪ᮌᮦࡢ㟂せࡣ᳃ᯘࡢఆ᥇ࢆᣍࡁ㸪ᅵᆅ
⏝ࡢኚࡢ୍ᅉ࡞ࡗ࡚࠸ࡿ㸬
ᮏ◊✲࡛ࡣ㸪ᑗ᮶ࡢ␆⏘≀㟂せ㔞ࢆࡶࡑࡢ⏕⏘
ᚲせ࡞∾ⲡᆅࡢ㟂せ㔞ࢆ᥎ィࡍࡿࡶࠊᑗ᮶ࡢᮌᮦ
㟂せ㔞࠾ࡼࡧࡑࡢ⏕⏘ᚲせ࡞ᯘᆅࡢ㟂せ㔞ࢆ᥎ィࡍࡿ㸬
ࡲࡓ㸪㎰ᆅ࣭ᯘᆅ㠃✚ࡢᢚไ࣏ࢸࣥࢩࣕࣝࡘ࠸᳨࡚ウ ࡍࡿ㸬
2. ᪉ἲ
(1) ◊✲ࡢᯟ⤌ࡳ
ᮏ◊✲࡛ࡣ㸪Ẽೃኚື㛵ࡍࡿᨻᗓ㛫ࣃࢿࣝ㸦IPCC㸧
ࡼࡿ♫⤒῭ࢩࢼࣜ࢜㸦Shared Sociecinomic Pathways:
SSPs㸧ᇶ࡙࠸࡚2010ᖺࡽ2100ᖺࡲ࡛5ᖺẖ᥎ィࢆ
⾜ࡗࡓ㸬SSPs࡛ࡣ㸪⦆⟇ᑐࡍࡿᅔ㞴ᗘ㐺ᛂ⟇ᑐ ࡍࡿᅔ㞴ᗘࡢ⤌ࡳྜࢃࡏ࡛5ࡘࡢࢩࢼࣜ࢜㸦SSP1ࠥSSP5㸧 ࡀタᐃࡉࢀ㸪SSP1: Sustainability㸦ᣢ⥆ྍ⬟㸧㸪SSP2: Con- tinuation㸦㐣ཤࡢᘏ㛗㸧㸪SSP3: Fragmentation㸦ศ᩿㸧㸪 SSP4: Inequality㸦᱁ᕪ㸧㸪SSP5: Conventional Development 㸦ᅾ᮶ᆺⓎᒎ㸧ࡢྛࢩࢼࣜ࢜ࡀᐃ⩏ࡉࢀ࡚࠸ࡿ㸬ࡇࡢࢩ ࢼࣜ࢜ࡢࢹ࣮ࢱ࣮࣋ࢫ4)࡛ࡣ㸪ࡇࢀࡽࡢࢩࢼࣜ࢜ࡢ㸪 2010ᖺࡽ2100ᖺࡲ࡛ࡢྛᅜࡢேཱྀGDPࡢࢩࢼࣜ࢜ࢆ
ᚓࡿࡇࡀ࡛ࡁࡿ㸬ᮏ◊✲࡛ࡣ㸪ࡇࢀࡽࡍ࡚ࡢࢩࢼࣜ
࢜ࡘ࠸࡚㸪᳨ウࢆ⾜ࡗࡓ㸬
ᑐ㇟ᆅᇦࡣ㸪ୖグࢩࢼࣜ࢜ࡽ㸪ேཱྀࡢࢹ࣮ࢱࡀᚓࡽ
ࢀࡿ187ࡢᅜᆅᇦࡋ㸪ᑗ᮶࠾ࡅࡿ㸪స≀㟂せ㔞㸪 第43回環境システム研究論文発表会講演集 2015年10月
ᅗ-1ᮏ◊✲ࡢ᥎ィࣇ࣮ࣟ
∾ⲡ㟂せ㔞㸪ᮌᮦ㟂せ㔞ࢆ᥎ィࡋ㸪ࡑࢀࡽࢆ⏕⏘ࡍࡿࡢ
ᚲせ࡞㠃✚ࡍ࡞ࢃࡕ㎰ᆅᯘᆅࡢ⟬ฟࢆ⾜ࡗࡓ㸬ᮏ◊
✲ࡢࣇ࣮ࣟࢆᅗ-1♧ࡍ㸬 (2) ㎰ᆅ㠃✚㟂せ㔞ࡢ᥎ィ a) ⪔సᆅ㠃✚㟂せࡢ᥎ィ
⏣ᮧࡽ2)ࡢ᪉ἲࡶ࡙ࡁᑗ᮶ࡢ㣗ᩱ࣭㣫ᩱ࣭࠾ࡼࡧ
ࣂ࢜⇞ᩱ㟂せ㔞ࢆ᭱᪂ࡢࢹ࣮ࢱ᭦᪂ࡋ࡚᥎ィࡋ࡞࠾
ࡋ㸪ࡑࢀࡽࢆ⏕⏘ࡍࡿࡢᚲせ࡞స≀ࡢ㟂せ㔞ࢆ⟬ฟࡋ ࡓ㸬ḟ㸪ࡑࡢస≀ࢆ⏕⏘ࡍࡿࡓࡵᚲせ࡞㎰ᆅ㠃✚
⟬ࡋ㸪ࡑࢀࢆ⪔సᆅ㟂せ㔞ࡋࡓ㸬 b) ∾ⲡᆅ㟂せ㔞ࡢ᥎ィ
⏣ᮧࡽ2)࡛᥎ィࡋࡓୡ⏺ࡢ187ࡢᅜ࣭ᆅᇦࡢ㣗ᩱ㟂せ 㔞ࢆࡶ㸪⏕⏘∾ⲡࢆᚲせࡍࡿ∵⫗㸪∵ஙࢆᑐ㇟
㸪⏕⏘ࡍࡿࡢᚲせ࡞∾ⲡࡢ㔞∾ⲡᆅࡢ㠃✚ࢆ᥎ィ ࡋࡓ㸬
ࡲࡎ㸪kᅜࡢtᮇ࠾ࡅࡿ␆⏘≀iࡢ㟂せ㔞ࢆ‶ࡓࡍࡓ
ࡵࡢ∾ⲡࡢ㟂せ㔞DMk,i(t)(kg DM)ࢆୗグࡢᘧ(1)࡛⟬ฟࡋ ࡓ㸬
i k i k i k i k i
k t W t NE FM ED
DM ,() ,() , , / , (1) ࡇࡇ࡛㸪Wk,i(t)ࡣkᅜࡢtᮇ࠾ࡅࡿ␆⏘≀iࡢ㟂せ㔞 (kg)4)㸪NEk,iࡣkᅜ࠾ࡅࡿ␆⏘≀i1kg࠶ࡓࡾࡢᐙ␆iࡢ
࢚ࢿࣝࢠ࣮㟂せ㔞(MJ/kg)5)㸪FMk,iࡣkᅜ࠾ࡅࡿᐙ␆iࡢ 㣫ᩱࡢ࠺ࡕࡢ∾ⲡᦤྲྀྜ(-)5)㸪EDk,iࡣkᅜ࠾ࡅࡿ∾ⲡ 1kg࠶ࡓࡾࡢᐙ␆iࡢᦤྲྀ࢚ࢿࣝࢠ࣮㔞(MJ/kg DM)5)࡛࠶
ࡿ㸬NEk,i㸪FMk,i࠾ࡼࡧEDk,iࡘ࠸࡚ࡣWirsenius5)ࢆཧ⪃
㸪187ࡢᅜ࣭ᆅᇦࢆ7ࡘࡢᆅᇦᩚ⌮ࡋ㸪Wirsenius5)
࠾ࡅࡿ1993ᖺࡢ್୍࡛ᐃ್ࡋ࡚᥎ィࢆ⾜ࡗࡓ㸬ࡲࡓ㸪 EDk,i 㛵 ࡋ ࡚ 㸪Wirsenius5)࡛ ࡣ ࠕCropland pastureࠖ ࠕPermanent pasture, oversownࠖࠕPermanent pasture, nativeࠖࡢ 3ࡘࡢ∾ⲡᆅࡀ♧ࡉࢀ࡚࠸ࡿࡀ㸪ࠕPermanent pasture, over- sownࠖࡀ᭱ࡶ⌧≧ࡢ∾ⲡᆅ㏆࠸ࡓࡵ㸪ࡑࡢ್ࢆ⏝ࡋ ࡓ㸬ྛᆅᇦ࠾ࡅࡿྛࣃ࣓࣮ࣛࢱࡢ್ࢆ⾲-1♧ࡍ㸬
ḟᘧ(1)࡛ồࡵࡓDMk,i(t)ࡽ㸪kᅜࡢtᮇ࠾ࡅࡿᐙ
␆iࡢ∾ⲡᆅ㟂せ㔞GLk,i(t)ࢆୗグࡢᘧ(2)ࡼࡾ᥎ィࡋࡓ㸬 (2) ࡇࡇ࡛㸪Ykࡣkᅜࡢ∾ⲡᆅ1ha࠶ࡓࡾࡢ∾ⲡ౪⤥࣏ࢸࣥ
ࢩࣕࣝࡢᖹᆒ್(Mg DM/ha)5)࡛࠶ࡿ㸬᭱ᚋ㸪ᘧ(3)ࡼ
ࡾྛᅜࡢ∾ⲡᆅ㟂せ㔞ࢆྜィࡍࡿࡇࡼࡾୡ⏺ࡢ∾ⲡ ᆅ㟂せ㔞ࢆ⟬ฟࡋࡓ㸬
(3)
c) ㎰ᆅ㠃✚㟂せ㔞ࡢ⟬ฟ
๓㡯a)㸪b)࡛ồࡵࡓ⪔సᆅ㠃✚㟂せ㔞㸪∾ⲡᆅ㠃✚
㟂せ㔞ࢆ㊊ࡋྜࢃࡏࡿࡇ࡛㸪㎰ᆅ㠃✚㟂せ㔞ࡋࡓ㸬 (3) ᯘᆅ㠃✚㟂せ㔞ࡢ᥎ィ
a) ᮌᮦ㟂せ㔞ࡢ᥎ィ
ᮏ◊✲࡛ࡣ㸪Kayo et al.6)ᇶ࡙࠸࡚㸪ᮌᮦࢆ〇ᮦ㸪ྜ
ᯈ㸪ᮌ㉁࣮࣎ࢻ㸪⣬࣭ᯈ⣬㸪ᮌ㉁⇞ᩱࡢ5⏝㏵ศࡅ࡚
㟂せ㔞ࡢ᥎ィࢆ⾜ࡗࡓ㸬ྛ⏝㏵ࡈ㸪OECDࡢ33ࣨᅜ
BRIICSࡢ6ࣨᅜࡢྜィ39ࣨᅜࢆᑐ㇟ࡋ࡚㸪1ே࠶ࡓࡾ
㉎㈙ຊᖹ౯GDP7)ࢆㄝ᫂㛵ᩘ㸪1ே࠶ࡓࡾᮌᮦ㟂せ㔞ࢆ⿕
ㄝ᫂ኚᩘࡋ࡚ᅇᖐศᯒࢆ⾜࠸㸪࡚ࡢᅇᖐಀᩘࡢ⤫ィ
ⓗ᭷ពᛶࡀ☜ㄆ࡛ࡁࡓࣔࢹࣝࡢ୰࡛᭱ࡶỴᐃಀᩘࡢ㧗࠸
ࡶࡢࢆ᥇⏝ࡋࡓ㸬ලయⓗࡣ㸪〇ᮦ㸪ᮌ㉁⇞ᩱࡢ2⏝㏵
⾲-1 ∾ⲡ㟂せ㔞ࡢ᥎ィ࠾ࡅࡿྛಀᩘࡢ್
ᆅᇦ
∵ங ∵⫗
NEk,i
(MJ/kg)
FMk,I
(-)
EDk,i
(MJ/kg DM)
NEk,i
(MJ/kg)
FMk,i
(-)
EDk,i
(MJ/kg DM)
ᮾࢪ 10.96 0.63 7.7 313 0.65 7.7
ᮾ࣮ࣚࣟࢵࣃ 9.95 0.50 8.4 160 0.38 8.4
ࣛࢸ࣓ࣥࣜ࢝࠾ࡼࡧ࢝ࣜࣈᾏㅖᅜ 13.2 0.76 7.4 264 0.74 7.4
ࣇࣜ࢝࠾ࡼࡧすࢪ 14.32 0.63 8.2 285 0.65 8.2
࣓ࣜ࢝࠾ࡼࡧ࢜ࢭࢽ 6.90 0.19 8.3 132 046 8.3 ༡ࢪ࠾ࡼࡧ୰ኸࢪ 13.82 0.37 7.4 499 0.40 7.4 ࢧࣁࣛ௨༡ࣇࣜ࢝ 29.1 0.69 7.3 373 0.69 7.3 す࣮ࣚࣟࢵࣃ 7.42 0.21 8.4 126 0.40 8.4
࡛ࡣᘧ(4)ࡢࡼ࠺୍ḟ㛵ᩘ㸪ྜᯈ㸪ᮌ㉁࣮࣎ࢻ㸪⣬࣭
ᯈ⣬ࡢ3⏝㏵࡛ࡣᘧ(5)ࡢࡼ࠺ୖฝࡢ2ḟ㛵ᩘࡢᅇᖐศ ᯒࡢ⤖ᯝࢆ⏝࠸࡚᥎ィࡋࡓ㸬
1 , 1
, (t) DGDP (t)E
DWkj PCk (4)
^ `
2 , 22 , 2
,(t) D GDP (t) E GDP (t)J
DWkj PCk PCk (5)
ࡇࡇ࡛㸪DWk,,j(t)ࡣkᅜࡢtᮇ࠾ࡅࡿᮌᮦ⏝㏵jࡢ1ே1ᖺ࠶
ࡓࡾ㟂せ㔞(m3/ே/ᖺ)㸪ࡓࡔࡋ⣬࣭ᯈ⣬ࡣ(kg/ே/ᖺ)㸪
GDPPC,k(t)ࡣ݇ᅜࡢݐᮇ࠾ࡅࡿ㉎㈙ຊᖹ౯1ே࠶ࡓࡾGDP
㸦2005ᖺᅜ㝿ࢻࣝ㸧㸪Į1㸪ȕ1㸪Į2㸪ȕ2㸪Ȗ2ࡣࣃ࣓࣮ࣛࢱࢆ
⾲ࡍ㸬
ḟ㸪ᘧ(4)(5)࡛ồࡵࡓᮌᮦ㟂せ㔞ྛᅜྛᮇ࠾ࡅ
ࡿேཱྀPk(t)4)ࢆࡎࡿࡇ࡛㸪ྛᅜࡢྛᮇ࠾ࡅࡿ⏝㏵
ูࡢᮌᮦ㟂せ㔞DWTotal,k,,j(t) (m3)ࢆ⟬ฟࡋࡓ㸬 ) ( ) ( )
( ,, ,
,
, t DW t P t
DWTotalkj kj k (6)
ࡉࡽ㸪ኴ⟬ಀᩘCFk,j(m3/m3)8)ࢆࡎࡿࡇࡼࡾ
ᮌᮦ㟂せ㔞ࡢኴ⟬㔞DLk,j(m3)ࢆ⟬ฟࡋࡓ㸬
j j k Total j
k t DW t CF
DL, () ,, () (7) ࡓࡔࡋ⣬࣭ᯈ⣬ࡘ࠸࡚ࡣ〇ရࡢࡍ࡚ࡀᮌᮦ⏤᮶࡛ࡣ
࡞࠸ࡓࡵኴ⟬ಀᩘ(m3/kg)ࢆࡌࡿࡶ㸪ᮌᮦࣃ
ࣝࣉ⏝⋡9)ࡶ⪃៖ࡋ࡚ኴ⟬㔞DLk,j(m3)ࢆ⟬ฟࡋࡓ㸬
k j j k Total j
k t DW t CF RWP
DL,() ,, () (8)
ࡇࡇ࡛㸪RWPkࡣkᅜࡢᮌᮦࣃࣝࣉ⏝⋡9)ࢆ⾲ࡋ㸪2008ᖺ ࡢ್࡛ᅛᐃࡋ࡚⏝࠸ࡓ㸬ࡲࡓ㸪ᮌᮦࣃࣝࣉ⏝⋡ࡀ᫂
ࡢᅜ࣭ᆅᇦࡘ࠸࡚ࡣ㸪ୡ⏺ᖹᆒ್ࢆ⏝ࡋࡓ㸬 b) ᯘᆅ㠃✚㟂せ㔞ࡢ᥎ィ
๓㡯a)࡛ồࡵࡓኴ⟬ࡢᮌᮦ㟂せ㔞ࢆᯘᆅࡢᮌᮦᡂ
㛗㔞10)(m3/ha/ᖺ)࡛㝖ࡍࡇࡼࡾ㸪ᯘᆅ㠃✚㟂せ㔞ࢆ⟬
ฟࡋࡓ㸬ᮏ◊✲࡛ࡣ㸪ᮌᮦࡢ㈠᫆ࢆ⪃៖࡛ࡁ࡚࠸࡞࠸ࡇ
ࡽ㸪ྛᅜࡢ㟂せ㔞౪⤥㔞ࡢࡎࢀࡀ⏕ࡌࡿࡓࡵ㸪ྛ
ᅜࡢᯘᆅࡢᮌᮦᡂ㛗㔞ࢆ⏝࠸ࡿࡢࡣ㐺ษ࡛࠶ࡿ⪃࠼
ࡽࢀࡿ㸬ࡑࡇ࡛㸪ᮏ◊✲࡛ࡣᮌᮦᡂ㛗㔞ࡢୡ⏺ᖹᆒࢆ⏝
࠸࡚⟬ฟࢆ⾜ࡗࡓ㸬
(4) ᯘᆅ㠃✚㟂せ㔞๐ῶ࣏ࢸࣥࢩࣕࣝࡢ᥎ィ
ୖグ᪉ἲ࡛ồࡵࡓ᥎ィ⤖ᯝࢆࡶ㸪ᑗ᮶๐ῶࡀᮇᚅ
࡛ࡁࡿᯘᆅ㠃✚㟂せ㔞㸪ࡍ࡞ࢃࡕ๐ῶ࣏ࢸࣥࢩࣕࣝࡢ᥎ ィࢆ⾜࠺㸬ᯘᆅ㠃✚㟂せ㔞ࡢ๐ῶ᪉ἲࡣࡁࡃศࡅ࡚
2ࡘࡢ᪉ἲࡀ⪃࠼ࡽࢀࡿ㸬୍ࡘ┠ࡣ㸪㎰ᆅ㠃✚㟂せ㔞ࢆ
๐ῶࡍࡿࡇࡼࡾ㸪ᑗ᮶ࡢ㎰ᆅ㟂せᣑక࠺ᯘᆅࡢ ᅵᆅኚࢆ๐ῶࡍࡿ᪉ἲ࡛࠶ࡿ㸬ࡘ┠ࡣ㸪ᑗ᮶ࡢᮌᮦ
㟂せ㔞ࢆ๐ῶࡍࡿࡇࡾ㸪⏝ࡍࡿᯘᆅ㠃✚ࢆῶࡽ
ࡍ᪉ἲ࡛࠶ࡿ㸬ᮏ◊✲࡛ࡣ㸪୍ࡘ┠ࡢ๐ῶ᪉ἲᑐࡋ࡚㸪
⫗㣗㟂せࡢኚ㸪㣗ရᗫᲠ≀ࡢ๐ῶࡼࡿ㎰ᆅࡢ๐ῶ࣏
ᅗ-2⪔సᆅ㟂せ㔞
ᅗ-3∾ⲡᆅ㟂せ㔞
ࢸࣥࢩࣕࣝ㸪ࡘ┠ࡢ๐ῶ᪉ἲᑐࡋ࡚⣬࣭ᯈ⣬ࡢᮌ
ᮦ㟂せ㔞ࢆ๐ῶࡋࡓ㝿ࡢᯘᆅ⏝㠃✚ࡢ๐ῶ࣏ࢸࣥࢩࣕ
ࣝࡘ࠸᳨࡚ウࢆ⾜࠺㸬
3. ⤖ᯝ⪃ᐹ
(1) ㎰ᆅ㠃✚㟂せ㔞 a) ⪔సᆅ㠃✚㟂せ
ᅗ-2⪔సᆅ㠃✚㟂せ㔞ࡢ᥎ィ⤖ᯝࢆ♧ࡍ㸬⪔సᆅ㠃
✚ࡣ࡛᭱1.74 Gha㸦SSP5㸪2045ᖺ㸧࡞ࡾFAOSTAT
࠾ࡅࡿ2010ᖺࡢᐇ㝿ࡢ✭㠃✚㸦1.16 Gha㸧ࡽ⣙1.4ಸ
࡞ࡿ⤖ᯝ࡞ࡗࡓ㸬ࡍ࡚ࡢࢩࢼࣜ࢜࠾࠸࡚㸪2030 ᖺࡈࢁࡲ࡛ቑຍࡋ㸪ࡑࡢᚋSSP3࡛ࡣࡰᶓࡤ࠸ࡑࡢ
ࡢࢩࢼ࡛ࣜ࢜ࡣ㸪ேཱྀࡢῶᑡ㸪స≀ࡢ༢㠃✚ᙜࡓ
ࡾࡢ✭㔞㸦⋡㸧ࡢୖ᪼ࡼࡾ㸪⪔సᆅ㠃✚㟂せ㔞ࡣ ῶᑡࡍࡿ⤖ᯝ࡞ࡗࡓ㸬ᮏ◊✲࠾࠸࡚㸪㔞㛵ࡋ࡚
ࡣ㸪ᑗ᮶࠾࠸࡚ࡶࡁࡃᨵၿࡉࢀࡿࢩࢼ࡛ࣜ࢜᥎ィࢆ
⾜ࡗ࡚࠸ࡿࡓࡵ㸪ᅗ-2ࡢ᥎ィ⤖ᯝࡼࡾࡶࡉࡽከࡃࡢ⪔
సᆅ㠃✚ࡀᚲせ࡞ࡿྍ⬟ᛶࡀ⪃࠼ࡽࢀࡿ㸬 b) ∾ⲡᆅ㠃✚㟂せ㔞
ᅗ-3∾ⲡᆅ㠃✚㟂せ㔞ࡢ᥎ィ⤖ᯝࢆ♧ࡍ㸬∾ⲡᆅ㠃
✚㟂せ㔞ࡣ࡛᭱2.82 Gha㸦SSP3㸪2100ᖺ㸧᥎ィࡉࢀ㸪 ᥎ィࡋࡓ2010ᖺࡢ1.12 Ghaࡽ㸪⣙2.4ಸቑຍࡍࡿ᥎
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
2010 2015 2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 2070 2075 2080 2085 2090 2095 2100
⪔ స స ᆅ 㠃 㠃
✚
SSP1 SSP2 SSP3 SSP4 SSP5 2010(FAO) Gha
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
2010 2015 2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 2070 2075 2080 2085 2090 2095 2100
∾ ⲡ ⲡ ᆅ 㠃 㠃
✚ SSP1
SSP2 SSP3 SSP4 SSP5 2010(FAO) Gha
ᅗ-4㎰ᆅ㟂せ㔞
ᅗ-5ᮌᮦ㟂せ㔞㸦SSP5㸧
ィࡉࢀࡓ㸬ᮏ◊✲࡛ࡣ㸪∾ⲡ㟂せ㔞ࢆ㠃✚ኚࡍࡿ㝿
㸪∾ⲡᆅ1ha࠶ࡓࡾࡢ∾ⲡࡢ౪⤥࣏ࢸࣥࢩࣕࣝ㸦᭱
್㸧ࢆ⏝࠸࡚࠸ࡿࡓࡵ᭱ࡢ∾ⲡᆅ㠃✚㟂せ㔞࠾࠸࡚
ࡶ㸪2100ᖺࡲ࡛ࡢᮇ㛫࡛㸪⌧ᅾࡢ㠃✚ࢆᣑࡍࡿᚲせࡣ
࡞࠸࠸࠺⤖ᯝ࡞ࡗࡓ㸬ࡋࡋ࡞ࡀࡽ㸪౪⤥࣏ࢸࣥࢩ
ࣕࣝ᭱㝈ࡲ࡛∾ⲡࢆ⏝ࡋࡓሙྜࡢ◁₍ࡸᅵᆅࡢຎ
➼ࡢ⎔ቃᙳ㡪ࡣ࡛᫂࠶ࡿࡓࡵ㸪ᚋ㸪ࡑࡢ⪃៖ࡣᚲ せ࡛࠶ࡿ㸬
c) ㎰ᆅ㠃✚㟂せ㔞
ᅗ-4⪔సᆅ㠃✚㟂せ㔞∾ⲡᆅ㠃✚㟂せ㔞ࡢ⤖ᯝࢆ
ྜࢃࡏࡓ㎰ᆅ㠃✚㟂せ㔞ࡢ⤖ᯝࢆ♧ࡍ㸬2100ᖺࡲ࡛ࡢ᥎ ィᮇ㛫࠾࠸࡚᭱ࡶ㎰ᆅ㠃✚㟂せ㔞ࡀࡁࡃ࡞ࡿࡢࡣ SSP3࡛࠶ࡿ࠸࠺⤖ᯝ࡞ࡗࡓ㸬SSP3ࡣ㸪⦆⟇㸪ᑐ ᛂ⟇ࡶᑟධࡣࡁ࡞ᅔ㞴ࢆక࠺♫ࡢࢩࢼ࡛ࣜ࢜
࠶ࡾ㸪㏵ୖᅜ࡛ࡣேཱྀቑຍࡣṆࡲࡽࡎ㸪ᡤᚓࡶቑຍࡋ࡞
࠸11)ࡉࢀ࡚࠸ࡿ㸬ඛ㐍ᅜ㸪㏵ୖᅜࡶ⤒῭Ⓨᒎࡀ㐍
ࡴSSP5ẚ࡚SSP3ࡢ㎰ᆅ㠃✚㟂せ㔞ࡀࡁࡃ࡞ࡗ࡚
࠸ࡿࡇࡽ㸪㎰ᆅ㠃✚㟂せ㔞㛵ࡋ࡚ࡣேཱྀቑຍࡀ
࡞ᅉᏊ࡞ࡗ࡚࠸ࡿ⪃࠼ࡽࢀࡿ㸬
(2) ᯘᆅ㠃✚㟂せ㔞 a) ᮌᮦ㟂せ㔞
ᑗ᮶ࡢᮌᮦ㟂せ㔞ࡀ᭱࡞ࡗࡓSSP5ࡢ⤖ᯝࢆᅗ-5
♧ࡍ㸬SSP5࠾ࡅࡿᮌᮦ㟂せ㔞ࡣ࡛᭱㸪17.1 Gm3࡞
ᅗ-6ᯘᆅ㠃✚㟂せ㔞
ࡾ㸪2010ᖺࡽ⣙4.1ಸ࡞ࡗࡓ㸬
⏝㏵ูࡳࡿ㸪〇ᮦࡀ༙ศ⛬ᗘࢆ༨ࡵ㸪2010ᖺࡢ 1.28 Gm3ࡽ㸪࠾ࡼࡑ3.7ಸࡢ4.80 Gm3ࡲ࡛ቑຍࡍࡿ᥎ ィࡉࢀࡓ㸬⣬࣭ᯈ⣬㸪ᮌ㉁࣮࣎ࢻ㸪ྜᯈ㛵ࡋ࡚ࡣ㸪 2010ᖺ௨㝆୍ᗘቑຍࡍࡿࡶࡢࡢ㸪SSP5࠾࠸࡚ࡣ㸪2050 ᖺ㏆࡛ࣆ࣮ࢡࢆ㏄࠼㸪ࡑࡢᚋ㸪ῶᑡࡍࡿ⤖ᯝ࡞ࡗࡓ㸬 ࡑࡢࡢࢩࢼ࡛ࣜ࢜ࡶ㸪SSP1࡛2060ᖺ㸪SSP2࡛2070ᖺ࡛
ࣆ࣮ࢡࢆ㏄࠼㸪ࡑࡢᚋῶᑡࡍࡿ⤖ᯝ࡞ࡾ㸪SSP4࡛ࡣ 2050ᖺࡲ࡛ቑຍࢆࡋ㸪ࡑࡢᚋᶓࡤ࠸ഴྥ㸪SSP3ࡣ2100ᖺ
ࡲ࡛ࡢᮇ㛫࠾࠸࡚㸪ቑຍࡋ⥆ࡅࡿ⤖ᯝ࡞ࡗࡓ㸬ࡲࡓ㸪 SSP5࠾࠸࡚ࡣ㸪⤒῭ᡂ㛗ඹᮌ㉁⇞ᩱࡢ㟂せࡀ
ᖜቑຍࡋ㸪ኴ⟬ࡢ㟂せ㔞ࡣ㸪2010ᖺࡢ0.72 Gm3
ࡽ㸪2100ᖺࡢ6.80Gm3ࡲ࡛⣙9.5ಸࡢ㟂せ㔞࡞ࡾ㸪2010 ᖺⅬ࡛ᮌᮦ㟂せయࡢ2⛬ᗘࢆ༨ࡵ࡚࠸ࡓࡀ㸪2100 ᖺࡣ࠾ࡼࡑ4ࡲ࡛㟂せࡀࡢࡧࡿ⤖ᯝ࡞ࡗࡓ㸬ࡇࢀ
ࡣ㸪1ே࠶ࡓࡾ㉎㈙ຊᖹ౯GDPᮌ㉁⇞ᩱ㟂せ㔞ࡢ㛵ಀ
࠾࠸୍࡚ḟ᭤⥺ࡀ᭱ࡶࣇࢵࢺࡋࡓࡓࡵ࡛࠶ࡿࡀ㸪⤒
῭ᡂ㛗కࡗ࡚ᮌ㉁⇞ᩱࡢ㟂せࡀ㧗ࡲࡾ⥆ࡅࡿ࠺
ࡘ࠸࡚ࡣ㸪᳨ウࡢవᆅࡀ࠶ࡿ㸬 b) ᯘᆅ㠃✚㟂せ㔞
ᮌᮦ㟂せ㔞ࢆࡶ⟬ฟࡋࡓᯘᆅ㠃✚㟂せ㔞ࢆᅗ-6
♧ࡍ㸬ᅇ⟬ฟࡋࡓᯘᆅ㠃✚㟂せ㔞ࡣኴ⟬ࡢᮌᮦ㟂 せࡽࡢ⟬ࡢ㝿㸪ᶞᮌࡢᡂ㛗㔞ࢆ⏝࠸࡚࠸ࡿࡓࡵ㸪ᮌ
ᮦࡢ㟂せࡼࡾ㸪ఆ᥇ࡉࢀ࡚㸪Ⲩᆅ࡞ࡿ㠃✚࡛ࡣ࡞ࡃ㸪 ࡑࡢⅬ࡛ࡢ㟂せࢆࡑࢀ௨㝆ࡶ㈥࠺ࡓࡵேⅭⓗ࡞ᖸ΅
ࡀຍࢃࡿ㠃✚ࢆ⾲ࡋ࡚࠸ࡿ㸬ᮏ◊✲࠾࠸࡚ࡣ㸪SSP5
࠾ࡅࡿ㸪ᯘᆅࡢ㟂せ㔞ࡀ᭱ࡶࡁࡃ4.63 Gha࡞ࡾ㸪 FAOSTAT࠾ࡅࡿ2010ᖺࡢᯘᆅ㠃✚࡛࠶ࡿ㸪4.03 Ghaࢆ
2080ᖺ㏆㉸࠼ࡿ⤖ᯝ࡞ࡗࡓ㸬SSP5ḟ࠸࡛ࡁࡃ
࡞ࡿண ࡉࢀࡓSSP2࠾࠸࡚ࡣ㸪⌧ᅾࡢᯘᆅ㠃✚ࢆ
ୖᅇࡿࡇࡣ࡞࠸ࡶࡢࡢ㸪IUCN࠾ࡅࡿಖㆤࡉࢀ࡚࠸
ࡿᯘᆅࡢ㠃✚㸦Protected land㸧ࢆ㝖࠸ࡓᯘᆅࡢ⏝ྍ⬟
㔞ࢆୖᅇࡿ⤖ᯝ࡞ࡗࡓ㸬ࡑࡢࡢࢩࢼ࡛ࣜ࢜ࡶᑗ᮶
ࢃࡓࡗ࡚ᯘᆅ㠃✚㟂せ㔞ࡣቑຍࡋ㸪᭱ࡶ㟂せ㔞ࡢᑡ࡞࠸
SSP4࡛ࡶ㸪2100ᖺࡣ2010ᖺࡢ⣙2.2ಸࡲ࡛㟂せ㔞ࡀቑຍ ࡍࡿ⤖ᯝ࡞ࡗࡓ㸬ேཱྀቑຍࡢࡁ࠸ࢩࢼ࡛ࣜ࢜࠶ࡿ
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
2010 2015 2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 2070 2075 2080 2085 2090 2095 2100
㎰ ᆅ ᆅ 㟂 せ せ 㔞
SSP1 SSP2 SSP3 SSP4 SSP5 Gha
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0
2010 2015 2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 2070 2075 2080 2085 2090 2095 2100
ᮌ
ᮦ
ᮦ 㟂 せ せ
ᮌ㉁⇞ᩱ
⣬࣭ᯈ⣬
ᮌ㉁࣮࣎ࢻ
ྜᯈ
〇ᮦ
Gm3
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
2010 2015 2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 2070 2075 2080 2085 2090 2095 2100
ᯘ ᆅ ᆅ 㠃
✚
✚ SSP1
SSP2SSP3 SSP4SSP5 2010(FAO) available forest(IUCN) Gha
ᅗ-7⏝㏵ู㎰ᆅ㟂せ㔞㸦SSP3㸧
SSP3ࡼࡾࡶ㸪⤒῭ᡂ㛗ࡢࡁ࠸ࢩࢼ࡛ࣜ࢜࠶ࡿ㸪SSP5
ࡸSSP2ࡢ᪉ࡀᑗ᮶ࡢᯘᆅ㠃✚㟂せ㔞ࡀࡁࡃ࡞ࡗࡓࡇ
ࡽ㸪ᯘᆅ㠃✚㟂せቑຍࡢ࡞せᅉࡣ⤒῭ᡂ㛗࡛࠶ࡿ
⪃࠼ࡽࢀࡿ㸬
(3) ᯘᆅ㠃✚㟂せ㔞ᢚไ࣏ࢸࣥࢩࣕࣝ
a) ㎰ᆅ㠃✚㟂せ㔞๐ῶ࣏ࢸࣥࢩࣕࣝ
ᑗ᮶ࡢ㎰ᆅ㠃✚㟂せ㔞ࡀ᭱ࡶࡁ࠸᥎ィࡉࢀࡓ SSP3ࢩࢼࣜ࢜ࡢ⏝㏵ู㎰ᆅ㠃✚㟂せ㔞ࢆᅗ-7♧ࡍ㸬ࣂ
࢜⇞ᩱ⏝ࡢ㎰ᆅࡣࡈࡃ୍㒊࡛㣗ᩱ㛵ಀࡍࡿ㎰ᆅࡀ㟂 せࡢ㒊ศࢆ༨ࡵࡓ㸬㣫ᩱ⏝ࡢస≀⏝ࡢ⪔సᆅ∾ⲡᆅ
ࢆྜࢃࡏࡓ㸪㣫ᩱ㛵ࡍࡿ㎰ᆅࡣయࡢ⣙7ࢆ༨ࡵ㸪
⫗㣗ࢆ๐ῶࡍࡿࡇ࡛ከࡃࡢ㎰ᆅࢆ๐ῶࡍࡿࡇࡀྍ⬟
࡛࠶ࡿࡇࡀࢃࡿ㸬௬㸪⌧ᅾࡢඛ㐍ᅜࡢ㣗ᩱᾘ㈝ࣃ
ࢱ࣮ࣥࡽ㸪10%ࡢ⫗㣗ࢆ๐ῶࡋࡓሙྜ㸪᭱࠾ࡼࡑ 320 Mhaࡢ㎰ᆅࡀ๐ῶ࡛ࡁࡿ᥎ィࡉࢀࡓ㸬せᣑ㎰ᆅ 㠃✚ࡀ࡛᭱࠶ࡿ㸪SSP5ࡢ2045ᖺ࠾ࡅࡿ576 Mhaࢆ⫗
㣗ࡢ๐ῶࡔࡅ࡛๐ῶࡍࡿሙྜ㸪ࡑࡢᮇ㛫࠾࠸࡚㸪⌧ᅾ ࡢඛ㐍ᅜࡢᦤྲྀࣞ࣋ࣝࡽ㸪27%ࡢ⫗㣗ࡢ๐ῶࡀᚲせ࡛
࠶ ࡿ 㸬 ḟ 㸪 㣗 ရ ᗫ Რ ≀ 㛵 ࡍ ࡿ ⪃ ᐹ ࢆ ⾜ ࠺ 㸬
FAOSTAT3)ࡼࡿ㸪2010ᖺ࠾࠸࡚㸪ୡ⏺య࡛࠾ࡼ
ࡑ4.52 Gtࡢ 㣗 ရ ᗫ Რ ≀ ࡀ Ⓨ ⏕ ࡋ ࡚ ࠾ ࡾ 㸪 ࡇ ࢀ ࡣ
FAOSTAT3)࠾ࡅࡿ㣗ᩱ㟂せ㔞ࡢ8.6%ࢆ༨ࡵࡿ㸬௬ࡍ
࡚ࡢ㣗ᩱᗫᲠ≀ࢆ๐ῶࡋࡓሙྜ㸪᭱500 Mhaࡢ㎰ᆅ ࡀ๐ῶ࡛ࡁࡿ᥎ィࡉࢀࡓ㸬ࡋࡋ࡞ࡀࡽ㸪ᢏ⾡㠃࣭⤒
῭㠃ࡽ㸪ࡍ࡚ࡢ㣗ᩱᗫᲠ≀ࢆ๐ῶࡍࡿࡇࡣ㸪ྍ
⬟࡛࠶ࡿ㸬Foresight13)ࡼࡿ㸪ࢠࣜࢫᨻᗓࡣ㸪2050ᖺ
ࡲ࡛㣗ရᗫᲠ≀ࢆ༙ῶࡍࡿࡇࢆ┠ᶆࡋ࡚࠾ࡾ㸪ࡇ ࡢ್ࡣ⌧ᐇⓗ࡛ᐇ⌧ྍ⬟࡞್ࡔࡉࢀ࡚࠸ࡿ㸬௬ࡇࡢ
┠ᶆࢆୡ⏺࠶࡚ࡣࡵ࡚⪃࠼ࡿ㸪ᑗ᮶㸪᭱250 Mhaࡢ㎰ᆅࢆ๐ῶࡍࡿࡇࡀ࡛ࡁࡿ㸬ࡇࢀࡼࡾ㸪せᣑ
㎰ᆅ㠃✚ࢆࣉࣛࢿࢱ࣮ࣜࣂ࢘ࣥࢲ࣮ࣜ㸦400Mha㸧ࡢ
⠊ᅖෆࡵࡿࡇࡀ࡛ࡁࡿࡀ㸪⌧≧ࡢ㎰ᆅ㠃✚ࢆᣑ
ࡏࡎ㣗ᩱࡢ⏕⏘ࢆ⾜࠺ࡓࡵࡣ㸪ࡢᑐ⟇⤌ࡳྜࢃ
ࡏ࡚ᐇࡍࡿᚲせࡀ࠶ࡿࠋ
b) ᯘᆅ㠃✚㟂せ㔞๐ῶ࣏ࢸࣥࢩࣕࣝ
ᮏ◊✲࠾࠸࡚ࡣ㸪ᮌᮦ5⏝㏵ࡢ࠺ࡕ㸪᭱ࡶ๐ῶࡀᐜ
࡛᫆࠶ࡿ⣬࣭ᯈ⣬⏝ࡢᮌᮦࡢ๐ῶࡘ࠸᳨࡚ウࢆ⾜ࡗࡓ㸬
⣬࣭ᯈ⣬ࡢ๐ῶ᪉ἲࡋ࡚ࡣ㸪⣬࣭ᯈ⣬ࡢ㟂せ㔞ࢆῶࡽ
ࡍ᪉ἲ㸪ᮌᮦ௨እࡢཎᩱࢆ⏝ࡋ࡚〇㐀ࡍࡿ᪉ἲ㸪⏕
⣬ࢆ⏝ࡍࡿ᪉ἲ➼ࡀ⪃࠼ࡽࢀࡿࡀ㸪ᮏ◊✲࡛ࡣ㸪᪉ἲ ࡣၥࢃࡎ㸪⣬࣭ᯈ⣬〇㐀⏝ࡢᮌᮦ㟂せ㔞ࢆ༙ῶࡉࡏࡓሙ
ྜࡢ๐ῶ࣏ࢸࣥࢩࣕࣝࡘ࠸᳨࡚ウࡋࡓ㸬ࡑࡢ⤖ᯝ㸪ᯘ ᆅ㠃✚ࡢ๐ῶ࣏ࢸࣥࢩࣕࣝࡣ࡛᭱ࡶ㸪90 Mha᥎ィࡉ
ࢀࡓ㸬ࡇࢀࡣ㸪᭱ࡶᯘᆅ㠃✚㟂せ㔞ࡀࡍࡃ࡞࠸SSP4ࡢ 㟂せቑຍ㔞1120 Mhaࡢ⣙6.7%ࡋ‶ࡓ࡞࠸㸬ࡲࡓ㸪 SSP5ࡢᯘᆅ㠃✚㟂せ㔞ࡣ⏝ྍ⬟࡞ᯘᆅࢆ᭱1140 Mha, SSP2࡛ࡣ270Mhaୖᅇࡗ࡚࠸ࡿࡓࡵ㸪ᯘᆅࡢಖㆤࢆ☜ᐇ
ࡍࡿࡓࡵࡣ㸪᭦࡞ࡿᮌᮦ㟂せࡢ๐ῶࡀᚲせ࡛࠶ࡿ㸬
4. ࠾ࢃࡾ
ᮏ◊✲࡛ࡣ㸪2100ᖺࡲ࡛ࡢ㛗ᮇࡢᮇ㛫ࢃࡓࡗ࡚㸪 IPCCࡢసᡂࡋࡓ♫⤒῭ࢩࢼࣜ࢜ࡶ࡙ࡁ㸪ࣂ࢜
⇞ᩱ࣭㣗ᩱ࣭㣫ᩱ㛵ࢃࡿస≀∾ⲡ㸪5⏝㏵࠾ࡅࡿ
ᮌᮦ㟂せࡢ᥎ィࢆ⾜࠸㸪ࡑࢀࡽࡢ⏕⏘ᚲせ࡞㎰ᆅ࣭ᯘ ᆅ㠃✚㟂せ㔞ࡢ᥎ィࢆ⟬ฟࡋࡓ㸬ࡲࡓ㸪ࡑࢀࡽࡢ㟂せࡢ ๐ῶ࣏ࢸࣥࢩࣕࣝࡘ࠸࡚㸪࠸ࡃࡘࡢ᮲௳ࢆࡶ᥎ ィࢆ⾜ࡗࡓ㸬ࡑࡢ⤖ᯝ㸪ᑗ᮶㸪⪔సᆅ㠃✚ࡣ࡛᭱1.74 Gha㸪∾ⲡᆅ㠃✚ࡣ᭱2.82 Ghaᚲせ࡛࠶ࡿ᥎ィࡉࢀ㸪 せᣑ㎰ᆅ㠃✚ࡣ㸪᭱576 Mha࡛࠶ࡗࡓ㸬ࡲࡓ㸪ᑗ᮶ ࡢᯘᆅ㠃✚㟂せ㔞ࡣ4.63 Gha࡛㸪2010ᖺࡢᐇ㝿ࡢᯘᆅ㠃
✚ࢆୖᅇࡿ⤖ᯝ࡞ࡗࡓ㸬
㎰ᆅ࣭ᯘᆅ㠃✚㟂せࡢ๐ῶ࣏ࢸࣥࢩࣕࣝࡋ࡚ࡣ㸪⫗
㣗ࡢ10%ࡢ๐ῶࡼࡾ320 Mha㸪㣗ရᗫᲠ≀ࡢ༙ῶࡼ
ࡾ250 Mhaࡢ㎰ᆅࡀ๐ῶ࡛ࡁࡿ᥎ィࡉࢀࡓ㸬᥎ィࡉࢀ
ࡓせᣑ㎰ᆅ㠃✚㸪᭱576 Mhaࢆ๐ῶࡍࡿࡓࡵ
ࡣ27%ࡢ⫗㣗ࡢ๐ῶࡀᚲせ࡞ࡿ㸬ࡲࡓ㸪㣗ရᗫᲠ≀
ࡢ༙ῶࡼࡾ㸪せᣑ㎰ᆅ㠃✚ࢆࣉࣛࢿࢱ࣮ࣜࣂ࢘ࣥࢲ
࣮ࣜࡢ⠊ᅖෆࡵࡿࡇࡣ࡛ࡁࡿࡀ㸪ࡇࢀࡔࡅ࡛ࡣ㎰
ᆅᣑࢆᢚ࠼ࡿࡇࡣ࡛ࡁ࡞࠸ࡓࡵ㸪ࡑࡢࡢᑐ⟇ࡢ
⤌ࡳྜࢃࡏࡀᚲせ࡞ࡿ⤖ᯝ࡞ࡗࡓ㸬ࡲࡓ㸪⣬࣭ᯈ⣬
⏝ࡍࡿᮌᮦࢆ༙ῶࡍࡿࡇ࡛㸪᭱90 Mhaࡢᯘᆅ㠃
✚㟂せࡀ๐ῶ࡛ࡁࡿ࠸࠺⤖ᯝ࡞ࡗࡓ㸬ࡇࡢ್ࡣ㸪ᯘ ᆅ㠃✚㟂せ㔞ࡢࡈࡃ୍㒊࡛࠶ࡿࡓࡵ㸪ᯘᆅࡢಖㆤࢆ☜ᐇ
ࡍࡿࡓࡵࡣ㸪᭦࡞ࡿᮌᮦ㟂せࡢ๐ῶࡢࡓࡵࡢᑐ⟇ࡀ ᚲせ࡛࠶ࡿ㸬
࡞࠾㸪ᮏ◊✲࠾࠸࡚ࡣ㸪ࣂ࢜⇞ᩱ࣭㣗ᩱ࣭㣫ᩱ࣭
ᮌᮦࡢ㍺ฟධࡣ⪃៖ࡋ࡚࠸࡞࠸ࡓࡵ㸪⮬ᅜ࡛ᾘ㈝ࡉࢀࡓ
ࣂ࢜⇞ᩱ࣭㣗ᩱ࣭㣫ᩱ࣭ᮌᮦࡣ㸪ࡍ࡚ᅜෆ࡛⏕⏘ࡉ
ࢀࡓ௬ᐃࡋ࡚࠸ࡿ㸬ᐇ㝿ࡣྛᆅᇦ࡛ᾘ㈝ࡉࢀࡿࣂ࢜
⇞ᩱ࣭㣗ᩱ࣭㣫ᩱ࣭ᮌᮦࡣእᅜ࡛⏕⏘ࡉࢀࡓࡶࡢࡶྵ
ࡲࢀࡿࡓࡵ㸪ᚋࡣ㈠᫆㛵ࡍࡿ⪃ᐹࡶᚲせ࡛࠶ࡿ㸬ࡲ
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
2010 2015 2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 2070 2075 2080 2085 2090 2095 2100
㎰ ᆅ ᆅ 㠃
✚
✚
⪔సᆅ(ࣂ࢜⇞ᩱ⏝) ⪔సᆅ(㣗ᩱ⏝)
⪔సᆅ(㣫ᩱ⏝) ∾ⲡᆅ Gha
ࡓ㸪ᯘᆅ㛵ࡋ࡚ࡣ㸪⣬࣭ᯈ⣬ࡢ๐ῶࡢࡳ࡛ࡣᯘᆅࡢಖ ㆤࡣ༑ศ࡛࠶ࡿࡓࡵ㸪ࡑࡢࡢ⏝㏵ࡢᮌᮦࡢ㟂せ๐ ῶ㛵ࡋ࡚ࡶࡇࢀࡽࡢㄢ㢟࡛࠶ࡿ㸬
ㅰ㎡㸸ᮏ◊✲ࡣ㸪⎔ቃ┬⎔ቃ◊✲⥲ྜ᥎㐍㈝㸦S-11-2㸧
ࡼࡿᡂᯝ࡛࠶ࡿ㸬ࡇࡇグࡋ࡚῝ㅰࡍࡿḟ➨࡛࠶ࡿ㸬 ཧ⪃ᩥ⊩
1) Rockstrom, J. et al.: Planetary boundaries: Exploring the safe operating space for humanity, Ecology and Society, 14(2), art.32, 2009
2) ⏣ᮧࡽ㸸㣗ᩱ࣭ࣂ࢜⇞ᩱ㛵ࢃࡿᑗ᮶ࡢ㎰ᆅ 㟂せࡑࡢᢚไ㸪➨ 42ᅇ⎔ቃࢩࢫࢸ࣒◊✲
ㄽᩥⓎ⾲ㅮ₇㞟㸪pp.33-38㸪2014
3) FAO: FAOSTAT, http://faostat.fao.org/,accessed inJun 2014 4) IISAS: SSP Database, https://secure.iiasa.ac.at/web-
apps/ene/SspDb/dsd?Action=htmlpage&page=about, accessed in Jul 2014.
5) Wirsenius, S: Human Use of Land and Organic Materials:
Modeling the Turnover of Biomass in Global Food System, Chalmers University of Technology and Goteborg University, 2000
6) C, Kayo et al.: Socioeconomic development and wood con- sumption, Journal of Forest Research, 20(3), pp.309-320, 2015.
7) World Bank㸸http://data.worldbank.org/㸪accessed in Jun 2014.
8) FAO: GENEVA TIMBER AND FOREST DISCUSSION 3$3(5 ʊ)25(67 352'8&7 &219(56,21 )$&7256)257+(81(&(5(*,21ʊ 9) RISI: Global Industry Statistics Database, 2009.
10) FAO: BULL, G, MABEE, W, and SCHARPENBERG, R, Global fibre supply model,1998
11) ⸨᳃┿୍㑻㸪ቑᙪ㸸ᑗ᮶ࡢẼೃኚࢆホ౯ࡍࡿ
ࡓࡵࡢ ᐊຠᯝ࢞ࢫฟ⤒㊰♫⤒῭ࢩࢼࣜ࢜㸪
᪥ᮏ࢚ࢿࣝࢠ࣮Ꮫㄅ㸪92㸪196-203㸪2013.
12) IUCN : Guidelines for Protected Area Management Categories.
IUCN and World Conservation Monitoring Centre (WCMC), Gland, Switzerland and Cambridge,UK. , 1994.
13) Foresight : The future of food and farming: challenges and choices for global sustainability. Final project report. United Kingdom Government Office for Science, London, 2011
㻔2015. 8. 28ཷ㻕
GLOBAL DEMAND FOR AGRICULTURAL AND FOREST LAND AND ITS SAVING POTENTIAL
Kento TAMURA, Chihiro KAYO, Tsubasa SATO, and Seiji HASHIMOTO
Increasing global demand for biomass resources will affect on change in land-use and various other planetary boundaries. Quantitative linkage between biomass resource use and planetary boundaries needs to be taken into account in assessments of sustainable biomass resource use. In this study, we developed models for estimating the future demand for crops, grasses and timber and for estimating the demand for agricultural and forest land: and we discussed potential measures to save the demand for land. Results show that the demand for agricultural land could reach 4.5 Gha, and maximum 567 Mha of agricultural land would be required additionally in the future. Also, 4.6 Gha of forestland would be needed at most, which is more than the forestland in 2010. We can reduce a certain amount of agricultural land by reduc- ing meat consumption and food waste. However, we need to examine further the reduction potential of wood demand for sustainable land use.
