Concerns about climate change

Transcription

1 3 Lrge-sle forests for ioenergy: ln-use, eonomi n environmentl implitions An nlysis of ntionl-level impts of plnttion forestry for energy proution in New Zeln useful tool for strtegi eision-mking. M. Jk n P. Hll Conerns out limte hnge n energy seurity hve riven mny ountries to reonsier their renewle energy options n strtegies. Energy from iomss is hs reeive signifint ttention in reent yers. While its potentil positive ontriutions re well reognize, evelopment of iofuels my lso hve negtive impts. Assessment of ountry s ioenergy options shoul thus inlue nlysis of: potentil iomss resoures; onsumer energy emn (given other potentil renewle energy options); ville tehnologies for onverting iomss into onsumer energy; eonomi ost; potentil reution in greenhouse gses; impts of ln-use hnge; ompetition with foo proution. An ssessment of this type hs een rrie out in New Zeln. It highlighte the ountry s potentil for prouing ioenergy from lrge-sle forestry n woul hve for ln use, the eonomy n the environment. This rtile summrizes the results of the stuy. A longer more etile isussion of the methoology n ssumptions ehin the work. Although the stuy ws speifi to New Zeln, it rises pertinent questions tht other ountries my onsier in nlysing their ioenergy options. While soio-politil spets re lso key omponents to suh eisionmking, they were outsie the sope of this stuy n not resse in etil. The evelopment of lrgesle forestry resoure on mrginl ln represents New Zeln s gretest opportunity for ioenergy Mihel Jk is Senior Sientist n Tem Leer (Green Proessing) n Peter Hll is Senior Sientist n Projet Leer (Renewle Energy), Sion, Rotoru, New Zeln. SCION Unsylv 34/35, Vol. 61, 010

2 4 ANALYSIS OF BIOENERGY OPTIONS The ove prmeters were ssesse through: rent iomss resiul resoures, the potentil of purpose-grown options, onsumer energy tehnologies (Hll eonomi osts n environmentl impts (through life-yle ssessment) of ntionlly relevnt iomss-to-onsumer energy onversion pthwys (Hll n Jk, The stuy etermine tht the min role of ioenergy in New Zeln is likely to e for het n liqui trnsport fuels, euse of the signifint potentil of other renewle resoures for eletriity genertion. The ssessment lso ientifie the evelopment of lrge-sle forestry resoure utilizing mrginl ln s the most signifint opportunity for ioenergy in New Zeln from the following perspetives. Potentil sle of energy supply. New Zeln hs suffiient low- to meium-proutivity grzing ln over 60 perent (9.3 million hetres) of ville proutive ln to estlish plnttion forest re- suffiient sle to supply ll of the ountry s emn for liqui fuels. ln in New Zeln is suitle for griulturl rops; using ll this re for rops for first-genertion liqui iofuel woul provie insuffiient liqui fuels to meet the ntionl emn n woul e etrimentl to foo rop proution n griul- Greenhouse gs reutions. Lifeyle ssessment of the full proution hin showe tht prouing lignoellulosi iofuel from plnttion forestry feestok woul hve muh lower environmentl impt thn prouing first-genertion iofuel from oil n strh rops, minly euse of the less intensive frming prties per unit of iomss. Tehnologil mturity n ost. Tehnology for onverting lignoellulosi iomss to liqui trnsport fuels is progressing rpily towrs ommeril viility (Sims et l., ASSESSMENT OF LARGE-SCALE FORESTRY FOR BIOMASS PRODUCTION The uthors ssesse the impts of ispling griulture (minly lowproutivity grzing) with forestry on hilly ln for four lrge-sle fforesttion senrios (Tle 1). In these senrios, potentil ln for fforesttion ws selete from Geogrphi Informtion Systems ln-use lss tse. The senrios iffer in ln-use lss, slope, ltitue n urrent ln use. It ws ssume tht lowest-vlue ln woul e use first (Senrio 1) n tht susequent senrios woul emre ln of progressively inresing vlue. The senrios presume the use of sru, ile, mrginl n low-to-moerte proutivity grzing ln s the resoure re rle ln. The potentil iomss proutivity for the senrios ws lulte se eonomi ost of iomss proution etween energy proution n other en uses (e.g. timer or ron reits), whih mitigtes risk for the forest owner. Potentil environmentl impts All senrios were ssoite with sig- tions (estimte using Intergovernmentl Pnel on Climte Chnge [IPCC] methoologies), oth from isplement of fossil fuel n from the hnge in ln use from griulture (whih ounts for out hlf of New Zeln s emissions) to forestry (Tle 4). The senrios were ssoite with inrese ron stoks, yer rottion forest, only 4 perent is hrveste per yer (Tle 4). Emission euse of the lower-intensity ln use tht is isple in these senrios. Beuse of reue levels of pstorl proution (Tle 5), the senrios lso showe enefits in numer of res of environmentl onern in New Zeln inluing erosion, seimenttion n nutrient lehing into wterwys (estimte using nutrient moel n sptil erosion moel) (Tle 4). Lrgely positive ioiversity impts were lso foun, in improve speies rihness of insets, plnts n ntive irs in omprison with psture n fition of these enefits requires further reserh. Afforesttion of ln tht ws not historilly foreste my not e esirle from ioiversity perspetive s it reues ntive grssln hitts. The nlysis showe tht in some res ing wter llotions lrge-sle fforesttion oul hve negtive impts on wter vilility n its suitility woul thus e questionle. Potentil for ompetition from lterntive ln uses The urrent return for the ln uner the senrios ws ssesse to etermine the eonomi viility of forestry for iomss for energy proution (To, greenhouse gs emissions ssoite with griulture, the return from the ln epens on the prie of ron (Tle 6) n the ompetitiveness of iomss for fuel ompre with urrent ln use epens on the prie of oil. Bse on the iofuel proution osts ssume in the stuy (Tle 7), ioenergy from forestry is more profitle option; it n provie Unsylv 34/35, Vol. 61, 010

3 5 TABLE 1. Afforesttion senrios erive using riteri se on ln-use lss, slope, ltitue n urrent ln use (re from minor ontriuting ln uses, suh s eer frming, not inlue) Senrio Totl re ( 000 h) Are from sruln ( 000 h) Are of sheep n eef psture ( 000 h) Note: TABLE. Totl sustinly extrtle iomss n orresponing energy potentil of eh fforesttion senrio to meet onsumer energy emn Senrio Totl extrtle iomss (million m 3 /yer) % of urrent onsumer energy emn % of het, or 0% of liqui trnsport fuel % of het n 4% of liqui trnsport fuel, or 7% of liqui trnsport fuel, or 73% of eletriity % of het n 100% of liqui trnsport fuel % of het n 100% of liqui trnsport fuel n 85% of eletriity In this tle het refers to ll inustril n omesti het, n eletriity is lrge-sle entrlize eletriity genertion. TABLE 3. Rnge of iomss yiels n proution osts Senrio Biomss Costs per ui metre yiel (m 3 /h) Growing Ros Hrvest Trnsport Totl NZ$ US$ NZ$ US$ NZ$ US$ NZ$ US$ NZ$ US$ Inlues ln rentl, ln preprtion, plnting, wee ontrol n forest mintenne (isount rte, 6%). 75 km. TABLE 4. Perentge hnge in key environmentl prmeters relevnt to New Zeln Senrio Reution in greenhouse gs emissions Cron stoks (million tonnes CO equivlent) Reution in nitrogen lehing Reution in erosion Reution in ville wter Reltive to urrent levels. Note tht lehing rtes n remin high for severl yers if the soil lrey ontins lrge mount of surplus nitrogen. Reltive to urrent levels. As perentge of nnul wter lne. TABLE 5. Reution in livestok numers Senrio Beef ttle Diry ttle Deer Sheep efore interest n txes) on ln selete for ioenergy Senrio Without ron prie With ron prie NZ$/h US$/h NZ$/h US$/h All pries were etermine uner lol onitions n onverte to US$ ssuming equivlent. TABLE 7. Assume osts of iofuel proution (per litre) Proess Bioethnol Fisher-Tropsh ioiesel NZ$ US$ NZ$ US$ Feestok proution Conversion e Totl All osts were etermine uner lol onitions n onverte to US$ ssuming Assumes yiel of 140 litres/m 3. Energy ontent of litre of ethnol is 0.67 litres of equivlent. Assumes yiel of 95 litres/m 3. Energy ontent of Fisher-Tropsh ioiesel is ssume to e the sme s fossil iesel. This vlue represents the upper oun of the vlues shown in Tle 3. e Unsylv 34/35, Vol. 61, 010

4 6 Privte onsumption (% hnge) Oil prie (US$/l) Eonomi impt of hnges in oil pries in New Zeln, with n without iofuels n other mesures to mitigte limte hnge 0.8 million hetres (ethnol) No iofuels 3.5 million hetres (ethnol n ioiesel) + inrese effiieny + high ron prie per hetre when the oil prie rehes oil prie ws US$147 per rrel in July my not e suffiient to le to lnuse hnge, s historilly frmers hve tene to sty with sheep n ttle frming even when its profitility is low. More reserh is require to unerstn the soil rivers, whih were not onsiere in this stuy. usiness-s-usul piture of the eonomy Currently, New Zeln otins hlf its onsumer energy n 93 perent of its trnsport fuels from importe oil, n its oil onsumption per unit of gross omesti prout (GDP) is the thir high- purhse this oil omes from griulturl proution. Therefore, rise in oil pries reltive to griulturl goos woul hve etrimentl effets on terms of tre n onsequently the eonomy s whole. This tre lso hs mjor impt on omesti greenhouse gs emissions, s it inlues oth the iret ron emissions from oil onsumption n the iniret greenhouse gs emissions from griulturl tivities use to py for importe oil. If ron priing in New Zeln inlues ll setors of the eonomy in the future (whih is likely uner the New Zeln Emissions Tring Sheme), then this tre will mgnify the potentil impt of emission ontrols on the eonomy. Thus, omesti proution of low-ron iofuels oul reue the eonomi impt of oth rising oil pries n striter emission ontrols in the future. The Figure emonstrtes how iofuels oul reue the eonomi impt of higher oil pries in the future. The points show the impt of hnges in oil pries n iofuel proution on pri- Resiues from timer proution for use in ioenergy: multipurpose forests prouing rnge of prouts inluing timer n iomss for fuel re likely to e the most eonomilly vile option Mroeonomi impt A generl equilirium moel ws use to estimte the onsequenes of using the ntion s ln resoures to proue iomss for fuel inste of other Severl eonomi senrios se on ssume proution osts, oil pries n ron stoks were ompre with SCION Unsylv 34/35, Vol. 61, 010

5 7 vte onsumption ( mesure of eonomi welfre) ompre with seline n n eonomy similr in struture to toy s. With no iofuels, n inrese in oil prie to US$300 per rrel woul reue privte onsumption y out 0.7 perent (ompre with the seline) euse of million hetres use for ethnol proution, oil imports woul e 15 perent less n the sme oil prie inrese woul result in smller eline in privte onsumption (of out 0.45 perent). fuels (3.5 million hetres use, reuing oil imports y 63 perent), plus effiieny gins n high ron prie, the mroeonomi impt of n inrese in oil prie to US$300 per rrel woul e more thn ompletely mitigte. Multipurpose forests prouing rnge of prouts inluing timer n iomss for fuel re likely to e the most eonomilly vile soure of iofuels, n the eonomi enefits of iofuels re gretest when they re ompetitive ple shows, long-term energy poliies shoul tke into ount tht iofuels my result in mroeonomi enefits in the future even though their urrent proution osts re higher thn the osts of importe fossil fuels. CONCLUSIONS A key fining of this ssessment is tht in New Zeln, growing lrge-sle forest plnttions for ioenergy on lowproutivity griulturl ln n hve signifint impt on greenhouse gs emissions through oth ln-use hnge from griulture to forestry n isplement of fossil fuels. It n lso hve other environmentl enefits in terms of improve wter qulity n erosion ontrol in omprison with griulture. This is se where ln-use hnge woul thus hve positive environmentl impts. These results woul most likely hol for other ountries where forests n e grown with low inputs on lowproutivity griulturl ln. This type of ssessment of ln-use, environmentl n eonomi impts of ioenergy t the ntionl level n help governments mke strtegi eisions out lrge-sle ioenergy opportunities s prt of ntionl energy supply. The pproh n lso help to ientify ntionl n regionl issues tht nee to e resse to relize the enefits of these opportunities. Biliogrphy Delruk, F. Zeln eonomy. Reserve Bnk of New Zeln Bulletin, Hll, P. & Giffor, J. Bioenergy options for New Zeln: sitution nlysis. Rotoru, New Zeln, Sion. Aville t: situtionanlysis.pf Hll, P. & Jk, M. Bioenergy options for New Zeln: pthwys nlysis. Rotoru, New Zeln, Sion. Aville t: t/ssets/ Options_Pthwys-Anlysis.pf Hll, P. & Jk, M. Bioenergy options for New Zeln: nlysis of lrge-sle ioenergy from forestry. Rotoru, New Zeln, Sion. Aville t: www. sionreserh.om/ t/ssets/pf_ from-forestry.pf Sims, R., Tylor, M., Sler, J. & Mee, W. From 1st- to n-genertion iofuel tehnologies. Pris, Frne, Interntionl Energy Ageny (IEA). Stroomergen, A. Generl equilirium nlysis of ioenergy options. Contriuting To, M., Zhng, W. & Kerr, S. Competition for ln etween iofuels, pstorl griulturl n sru lns. Contriuting report to Hll & Jk, Unsylv 34/35, Vol. 61, 010