報告書番号

Y95006

タイトル（和文）

土地利用競合を考慮した世界のプランテーションバイオマスエネルギー供給可能量の評価

タイトル（英文）

GLOBAL POTENTIAL SUPPLY OF BIOMASS ENERGY FROM PLANTATIONS IN LAND-USE COMPETIION

概要 （図表や脚注は「報告書全文」に掲載しております）

バイオマス（生物体）エネルギーは，持続可能な農業で生産すればＣＯ２を排出しないクリーンな再生可能エネルギーであり，一見すると植物の存在しうる土地が世界全体に広大にあることから，その将来のエネルギー供給可能性には一部で大きな期待がかけられている。しかし近代的エネルギーとして利用可能な量の評価にはばらつきがあり，あまりよく分かってはいない。本報告では，食料供給などの他の土地利用用途との競合を考慮した場合に，プランテーションによる近代的なバイオマスエネルギー生産にどの程度の供給可能量があるか見積もった結果，今後２０から３０年以内については余剰耕地あるいは潜在耕地が多く存在することから年間３５ＥＪ程度が可能と見込まれるが，５０から１００年といった長期的な視野では，最大で年間３５３ＥＪ程度が見込まれる一方で，食料需給と土地需給状況次第では，全く供給量が見込めない可能性もあることが分かった。

概要 （英文）

WE ESTIMATED GLOBAL POTENTIAL SUPPLY OF BIOMASS ENERGY FROM PLANTATIONS,TAKING COMPETITION WITH OTHER LAND-USE FACTORS SUCH AS FOODS AND WOOD PRODUCTION INTO ACCOUNT. THE MAJOR FINDINGS ARE SUMMARIZED AS FOLLOWS: (1)TWO METHODS WERE USED FOR ESTIMATION: (A)LAND AREA OF OPEN FOREST AND EXPLOITABLE FOREST. (B)AREA OF SURPLUS CROPLAND AND WITH CROP PRODUCTION POTENTIAL,TAKING LAND-USE COMPETITION WITH FOOD PRODUCTION INTO ACCOUNT. (2)FROM METHOD (A), THE LAND AREA AVAILABLE FOR BIOMASS PLANTATIONS IS ABOUT 173 MHA,ROUGHLY 35EJ/Y. SINCE THIS METHOD ASSUMES PRIMARY LAND-USE PATTERNS WILL BE UNCHANGED,THE ESTIMATE HOLDS FOR NO MORE THAN TWO DECADES. (3)FOR METHOD (B),ROUGHLY 33.5 EJ/Y FROM ABOUT 95 MHA OF PLANTATION IN 2010 IS AVAILABLE. SUCH A WIDE AREA IS AVAILABLE BECAUSE OF SURPLUS CROPLAND IN DEVELOPED COUNTRIES AND VAST AREAS WITH CROP PRODUCTION POTENTIAL IN LATIN AMERICA,ALTHOUGH THIS SCENARIO IMPLIES CONTINUED IMBALANCE OF THE NORTH-SOUTH FOOD SUPPLY. (4)IN 50 TO 100 YEARS,THE GLOBAL SUPPLY DEMAND BALANCE FOR LAND WILL BE TIGHT MAINLY DUE TO POPULATION AND ECONOMIC GROWTH IN DEVELOPING COUNTRIES. IN THIS CASE,THERE WILL BE NO LAND FOR BIOMASS PLANTATIONS. TAKING THE MOST OPTIMISTIC ASSUMPTION ON FOOD SUPPLY DEMMAND,ROUGHLY 350 EJ/Y COULD BE PRODUCED FROM PLANTATIONS. (5)ESTIMATED ENERGY PRODUCTION FROM BIOMASS PLANTATIONS OF 77 TO 208 EJ/Y FROM OTHER STUDIES SUGGESTS A RANGE OF 0 TO 353 EJ/Y. THIS WIDE RANGE REFLECTS THE MARGINAL CHARACTER OF BIOMASS PLANTATIONS BECAUSE THE AVAILABLE LAND AREA COMES FROM THE BALANCE OF POTENTIAL FOOD SUPPLY AND DEMAND. BIOMASS ENERGY FROM PLANTATIONS MIGHT PLAY A LIMITED ROLE,BUT WILL NOT BE A MAJOR PRIMARY ENERGY SOURCE UNTIL THE FOOD SUPPLY DEMAND BALANCE AS WELL AS LAND-USE COMPETITION BECOME EASIER.

報告者

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