Soy-milk-an-attributional-Life-Cycle-Assessment-examining-the-potential-environmental-impact-of-soy-milk.pdf

Soy Milk - an attributional Life Cycle Assessment examining the potential environmental impact of soy milk.

Project report Life Cycle Assessment AG200 Super#isors: $sa %o&erg' Anna Bj(r)lund Stoc)holm' %ay 200*

Group: LCA04 Authors: Sandra Birgersson Britta!Stina "arlsson Leif S(derlund

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Contents 1. Background ..................... ............................................ .............................................. .............................................. .......................................................... ................................... 3 2. Goal and scope definition .................... ........................................... .............................................. ....................................................... ..................................... ..... 3 2.1. Goal of the study ............................................................ ................................................................................... .................................................. ........................... 3 2.2. Functional unit ....................... .............................................. .............................................. ............................................................... ........................................ ....4 2.3. System boundaries .................... ........................................... ............................................... .......................................................... .................................. ...... 4 Geographical boundaries .................... ........................................... .............................................. .............................................. ................................... ............ 4 4 Loopback ..................... ............................................ .............................................. .............................................. ............................................. ................................. ........... 4 !ime boundaries .................... ........................................... .............................................. .............................................. ................................................ ......................... 4 4 "#uipment boundaries .................... ........................................... .............................................. .............................................. ....................................... ................ 4 4 2.4. $ssumptions and limitations limitatio ns ........................................................... ............................................................................................ ................................. 4 4 $ssumptions ...................... ............................................. .............................................. ............................................... .................................................... ............................ 4 Limitations ..................... ............................................ .............................................. .............................................. .................................................. ................................ ..... % 2.%. &mpact categories and impact assessment as sessment methods ................................................ ......... ' 3. Life cycle in(entory analysis .................... ........................................... .............................................. .................................................... ................................ ...) 3.1. *rocess flo+ chart .................... ........................................... .............................................. .............................................. ................................... ................... ....... ) 3.2. *roduction of soy so y milk ................................................................ ....................................................................................... ..................................... .............. , -anufacturing process of soy milk ...................................................... ............................................................................. ............................... ........ , , 3.3. ata collection ..................... ............................................ .............................................. ................................................................... ............................................ ... / 4. Life cycle interpretations ..................... ............................................ .............................................. .................................................. ................................... ........ 11 4.1. 0esults ........................ ............................................... .............................................. .............................................. ...................................................... ...............................11 Land use ...................... ............................................. .............................................. .............................................. ........................................................ .................................11 $cidificatio $cidif ication n ......... ................. ................ ................ ................ ................ ................ ................ ................. ................. ................ ................ ................ ................ ............ .... 12 "utrophication ...................... ............................................. .............................................. .............................................. ............................................... ........................ 13 Fossil "nergy se ..................... ............................................ .............................................. ............................................................ ..................................... .....14 limate change ...................... ............................................. .............................................. .............................................. ............................................. ...................... 1% Stratospheric oone depletion .................... ........................................... .............................................. .......................................... ......................... ......1) Summaried results ..................... ............................................ .............................................. .............................................. .................................... ................. .... 1, 4.2. iscussion and reflections .................... ........................................... .............................................. ............................................. ............................... ......... 1/ General discussion ..................... ............................................ .............................................. .......................................................... ................................... ...... 1/ iscussion of specific impact results ...................... ............................................. .......................................................... ................................... 1/ %. onclusions ....................... .............................................. .............................................. .............................................. .............................................. ............................... ........ 21 '. 0eferences ..................... ............................................ .............................................. .............................................. .............................................. ................................... ............ 22 $ppendices ..................... ............................................ .............................................. .............................................. .............................................. ...................................... ............... 23 $ppendi $ppen di 1 5 nutri nutritiona tionall (alue (aluess....... ................ ................. ................ ................ ................ ................ ................ ................ ............... ........... ........ ........ ...... ..23

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1. Background 0egular milk contains significant amounts of saturated fat6 protein and calcium. For millennia the milk from co+s has been processed into other products and milk in all different shapes is (ery popular. S+eden is the second largest consumer of milk measured per capita. Soy milk is a high protein6 ironrich milklike product produced from soybeans. &t resembles regular milk in appearance but is higher in protein and iron content and is cholesterolfree6 lo+ fat and lo+ sodium 718. Soy milk is a popular alternati(e to regular milk among lacto intolerant6 milkallergic and (egans. &t is6 ho+e(er6 also associated +ith the deforestation of the +orld9s rainforests. !he hinese ha(e been culti(ating soybeans for thousands of years and many belie(e that they also ha(e been making soy milk for centuries. By the sith century soybeans made their +ay to :apan and by the se(enteenth century they came to "urope. uring the $merican i(il ;ar6 soldiers used soybeans as a substitute for coffee beans and +ere thus making their o+n soy be(erage. &n the nineteenth century soy be(erages also became a(ailable in "urope. &n the 1/)reference? producer for this study.

2. Goal and scope definition &n this section6 the goal and definition of the study6 its functional unit and system boundaries are defined. $dditionally6 the assumptions and limitations of the study6 as +ell as the impact categories and use of impact assessment methods are eplained.

2.1. Goal of the study Soy milk has been a popular drink for a long time6 but has in S+eden been an increasingly popular substitute for regular milk in later years. $t the same time one can see a dropping consumption of regular milk. !herefore6 this attributional study has been conducted to analye the potential en(ironmental impact of soy milk and to pinpoint where in the life cycle of soy milk there is room for impro(ements6 seen from an en(ironmental point of (ie+. !he study is intended for the public as a source of information on ho+ soy milk may affect natural resources. $dditionally6 the study roughly compares the results found in this study +ith results from eternal L$ studies on regular milk to pro(ide some perspecti(e on the impact results.

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2.2. Functional unit !he functional unit is a #uantified measure of the performance of the functional outputs of the product system. !he functional unit for this study is one liter of drink6 +hich is the regular amount of one package of regular milk or soy milk. !he reason for the choice of one liter of drink6 instead of one package is due to the differences in the packaging re#uirements of the t+o drinks.

2.3. System boundaries Geographical boundaries !he study is based on regular milk consumption and daily shopping habits in Stockholm6 S+eden. !his has a huge impact on ho+ hea(ily the transportation of the soybeans to the production plants affects the o(erall flo+s of the analysis and should be considered +hen re(ie+ing the results. !he production of the soy milk is said to be in Belgium @+here $lpro produce their milkA6 +hich also affects the transportation issues.

Loop-back Some percentage of +aste bean fiber from the soy milk production6 called okara6 is used for production of animal food. !his is not included in the calculations.

Time boundaries Because of the short lifespan of the product6 and because the proect group assumes that no difference in drinking habits +ould come of a longer durability @>use?A6 no boundaries in time are set. Co+e(er6 there might be a boundary in the (alidity of the facts and data ac#uired for the calculations. Dne eample is the yield of today9s soybean crops6 +hich6 due to constantly impro(ing technology is estimated to increase massi(ely in the coming years 738. ;ith increasing yield (alues6 the data might become too uncertain o(er time and the proect group estimates the (alidity of the data to be no more than a maimum of % years.

Equipment boundaries &n order for the study not to become too etensi(e6 production of e#uipment needed for ra+ material etraction and production of the soy milk +as not taken into consideration.

2.4. Assumptions and limitations $ number of assumptions ha(e been made6 and some limitations eist in the study. !hese are presented in the follo+ing section.

ssumptions Transportation $ll transportation has been idealied into three maor partsE from farm to coast in Brail6 from the Brailian coast to the production site in Belgium and from production site to retailers in Stockholm6 S+eden. !hese distances +ere (ery roughly measured using online distance calculation tools6 and are therefore not accurate 748. $ccording to the nited States epartment of $griculture6 long distance transports of soybeans in Brail are made both using large lorries as +ell as trains 7%8. ;ithin Brail6

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transport +as therefore simplified to %<= by lorry and %<= by train @see section 3.2. for details on type of lorry and trainA. For transportation across the $tlantic Dcean6 a transoceanic freight ship +ith a load capacity of approimately 1331< 3 tons of soybeans +as used. Finally6 transportation from Belgium to S+eden +as made using a smaller lorry than in Brail @for details on type se section 3.2.A. $ll different (essels for transportation +ere assumed to be loaded +ith their respecti(e maimum capacities. ue to the etremely small distances compared to the interoceanic freights6 transports bet+een coast and production site +ere omitted and shopping of milk in Stockholm +as assumed to be made on foot.

Cultivation and production $ll soybeans used in this study are assumed to ha(e come from Brail6 e(en though many soy milk manufacturers sometimes choose to mi beans from different countries. ;hile Brail is the second largest producer of soybeans today6 there eists production in other countries6 such as the S$6 Belgium and hina. !he reason for the choice of Brail in this study is6 as earlier mentioned6 the fact that the producer of the reference product @one liter of $lpro soy milk +ithout any additionsA for the study states that they use soybeans coming only from Brail. $s described in section 3.26 there are a number of different processes included in the production of soy milk from soybeans. Co+e(er6 due to the difficulties in finding ra+ data for different processes6 one single energy (alue +as assigned to all processes combined. !his (alue is based on data from one single producer of soy milk in &ndia1. !he energy is declared to ha(e been produced from L.*.G @Li#uefied *etroleum GasA. !he (alue +as then directly con(erted in the Life ycle $ssessment soft+are Sima*ro to a mi of electricity from different sources in Belgium  import6 since no data +as a(ailable from the producer regarding the type of energy used in the Belgian production facility 7'8. !he fact that only one total (alue +as gi(en results in difficulties in finding indi(idual hotspots in the production process.

Limitations aste mana!ement !he +aste management process for the life cycle of the soy milk is not completeE it contains only the +aste process for the packaging of the soy milk. $ll milk is assumed to be consumed and no consideration has been made for potential energy costs due to lefto(er li#uid @se+age loadA.

"ata for comparison !o compare the impact category data ac#uired for the soy milk +ith data for regular milk6 se(eral eternal L$s +ere eamined. Co+e(er6 none of the studies matched impact categories +ith the different categories a(ailable in Sima*ro. $dditionally6 data gi(en in the eternal L$s of regular milk +ere not (ery detailed @do not include eplanations of processesA +hich means that some comparisons are difficult to make.

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!he producer +ishes to remain anonymous

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2.#. $mpact cate!ories and impact assessment methods !o ha(e the possibility to compare the potential en(ironmental impacts of both drinks an L$ on soy milk has been made and then compared to eisting data from different L$Hs of regular milk. !o be able to fairly compare the t+o drinks6 the same impact categories +hich ha(e been used in the study of regular milk ha(e been used for the study of soy milk. !he follo+ing si impact categories +ere used in both studiesH Land use Fossil energy use @or energy useA "utrophication $cidification limate change Done layer depletion &mpact assessment methods from Sima*ro "* 2<<).

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!. Life c"cle in#entor" anal"sis &n the follo+ing section6 flo+charts for the life cycle process as +ell as the production process are presented. Figure 1 displays the process flo+ chart. $dditionally6 the data collection is eplained.

3.1. %rocess flo& chart

Figure 1. Process flow chart of soy milk.

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3.2. %roduction of soy mil' &n this section6 the manufacturing process for soy milk is eplained and (isualied in Figure 2.

Figure 2. Production flow chart of soy milk.

$anufacturing process of so" milk !o create soy milk6 the only ingredients necessary are soybeans and +ater. !he +hole manufacturing process for soy milk is sho+n in Figure 3. ;hen the soybeans are har(ested they are cleaned in a grain ele(ator or bin. !he manufacturing process starts +ith de-hulling the beans. !his is done by steaming the soybeans +hich makes them split in half. !hen the hulls are remo(ed +ith a (acuum pump. $ specific enyme must be in(alidated by cooking in high pressure6 +ater and high temperature6 in order for the beans to be digestible for humans. Io+ the soybeans are ready for the first grinder. !he beans are roughly grinded and +ater is added. !hen the beans are put trough a fine grinder the further pul(erie the beans. !he product no+ consists of a hot slurry and to etract the tiny bits of beans that is still left in the slurry a centrifuge separate the soy milk from the bean fibers. !he +aste bean fiber6 okara6 is used for production of animal food. !he soy milk is then placed in large tanks and fla(ors6 (itamins and sugars may be added in this step. !he soy milk in this comparati(e L$ is being conducted on natural soy milk +ithout any accessory food factor. !he net step is to sterilize the soy milk. !his is done +ith pressure and (ery hot temperatures +ithin a (acuum. &t is (ery important that this is done in an aseptic en(ironment to make sure the soy milk is not introduced to any bacteria. $ll the follo+ing steps must be aseptic until packaging. !o pre(ent fat particles from separating the li#uid is homogenized . $fter this the soy milk is cooled do+n to room temperature by passing close by cold plates. Io+ the soy milk is stored in aseptic tanks until packaged in cardboard packages 7'8.

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Figure 3. Manufacturing process for soy milk

3.3. "ata collection ata collection has been a maor difficulty for this study6 as most manufacturers of soy milk ha(e not been able to share their production data +ith the proect group. -any manufacturers from se(eral different countries ha(e been contacted but only one manufacturer @from &ndiaA replied6 gi(ing the proect group the total energy consumption for the manufacturing process seen in Figure 3. !he data has been con(erted from energy from combustion of L.*.G @Li#uefied *etroleum GasA into the corresponding amount of -: of electricity mi @Belgium  importA. From this data6 assumptions ha(e been made concerning the energy data for the manufacturing in Belgium6 +here $lpro declare that they ha(e their soy milk production. !he data taken from Sima*ro ) is sho+n in !able 1. Some data from Sima*ro has been modified to fit the data from the manufacturer from &ndia. !he modified processes are sho+n as italic in !able 1.

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Table 1. 'ata and databases used in this study. Modified processes are in italic.

$ssembly

-aterialKprocess

$mount

atabase

"lectricity mi B  &mport S

<634 -: @1A

"!C"S /' System process

Soybeans6 at farmKB0  L$ <4

<61%4 kg @2A

"coin(ent system process

!ruck 4
<61/' tkm @3A


&nfra freight train S

16/%' tkm @4A


!ransport6 transoceanic freight shipKD" S

1623< tkm @%A


Soy milk manufacturing 5 ;ater for milk

!ap +ater6 at userKC S

<6/2, kg @'A


*ackaging

Production of liquid packaging board containers, at plant/RR ! "#$%&

2) g @)A


>sephase? 5 ooling for storage at home

0efrigerator6 small6 B

<62,, lday @,A

L$ Food 

0efrigerator6 big6 B

<6,'3 lday @/A

L$ Food 

>sephase? 5 ooling for storage at retail

0etail @cooling counter6 large storeA

<6% kg @1
L$ Food 

>sephase? 5 !ransport to retail

!ruck 2,t "!C S

<62<% tkm @11A

Soy milk manufacturing Soy milk manufacturing 5 Soybeans


@1A "nergy use for 1 liter of milk6 according to production in &ndia. on(erted from energy from combustion of L.*.G @Li#uefied *etroleum GasA into the corresponding amount of -: of electricity mi. @2A !he amount of soybeans needed for one liter of soy milk6 according to the &ndian production plant. @3A !ransportation from farm to coast in Brail6 for the e#ui(alent amount of beans for a half liter of soy milk. $pproimated that %<= of the beans6 for one liter of soy milk6 is con(eyed by rail and %<= by truck. @4A !ransportation from farm to coast in Brail6 for the e#ui(alent amount of beans for a half liter of soy milk. $pproimated that %<= of the beans6 for one liter of soy milk6 is con(eyed by rail and %<= by truck. @%A !ransportation from coast in Brail to production in Belgium6 for the e#ui(alent amount of beans for one liter of soy milk. @'A !he amount of +ater to produce 1kg milk. 1 liter of soy milk is approimately the same as 1 kg soy milk. @)A For one package6 according to data from !etra *ak. !otal +eight of package and indi(idual material percentages modified. @,A Based on the daily consumption for household +ith 1 person. 7)8 @/A Based on the daily consumption for a family household +ith 3 persons. 7)8 @1
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Table 2. 'ata and databases used in this study .

isposal scenario *ackaging  ontainer

*rocessK+aste scenario

$mount

atabase

!ransport6 lorry 3.%1't6 fleet a(erageK0"0 

<6<<13% tkm @1A


isposal6 aluminum6 <= +ater6 to municipal incinerationKC S

163% g @2A


isposal6 polyethylen6 <64= +ater6 to municipal incinerationKC S

'6)% g @3A


isposal6 packaging cardboard6 1/6'= +ater6 to municipal incinerationKC S

%6') g @4A


0ecycling6 cardboardK0"0 S

13623 g @%A


!ransport6 lorry 36%1't6 fleet a(erageK0"0 

<6<<<1% tkm @'A


0ecycling *"K0"0 S

3 g @)A


*ackaging 5 Lid

@1A !ransportation from recycling station to municipal incineration or recycling. @2A !he amount of aluminium in one package6 according to data from !etra *ak. $pproimated that 1<<= of the aluminium is incinerated. @3A !he amount of polyethylen in one package6 according to data from !etra *ak. $pproimated that 1<<= of the polyethylen is incinerated. @4A !he amount of cardboard in one package6 according to data from !etra *ak. $pproimated that 3<= of the cardboard is incinerated. !he ratio 3<= incineration of cardboard comes from information on !etra*ak9s homepage. @%A !he amount of cardboard in one package6 according to data from !etra *ak. $pproimated that )<= of the cardboard is recycled. !he ratio )<= recycling of cardboard comes from information on !etra*ak9s homepage. @'A !ransportation from recycling station to municipal incineration or recycling. @)A !he approimated amount of polyethylen in one lid. $pproimated that 1<<= of the polyethylen is recycled 5 this is because the lid is assumed to be taken off and recycled separately.  $ll transportation amounts +ere calculated by multiplying the +eight for the package and lid +ith the transport distance in km

%. Life c"cle interpretations !his section presents the results as +ell as a discussion and the conclusions dra+n from the study.

4.1. (esults Belo+6 the results of the different impact assessments6 as +ell as the summaried results are presented.

Land use !he culti(ation of soybeans in Brail +as found in the "coin(ent database. !he land used for the amount soybeans needed @<61% kgA for one liter of soy milk is <.%/ m . !his is based upon a 2

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land yielding 2 %44 kgKha. $ccording to the S$ the state of -aranhao is culti(ating soybeans on an area of 3<< <<< ha 7,8. &t produced )<< <<< tons in 2<<2K<3. !his land yields 2 3<< kgKha +hich means that <6'% m is needed to gro+ soybeans for one package of soy milk. $s technology de(elops the management of soybean is impro(ing. !he $maon region is estimated to ha(e potential to crop 3 '<< kgKha. !his indicates the efficiency +ill rise and less area +ill be needed to produce the same amount of soybeans. But as this efficiency is not yet reached6 the land use according to "coin(ent is considered to be a good estimation for this study. 2

$ccording to ederberg et al 2<<4 con(entional milk needs 16% m Kkg 7/8. !he area from the farm is the biggest contributor to the land usage6 but land usage for co+ feeds are taken into consideration. 2

Since soybeans gro+ closely on plants6 one s#uare meter of plants can produce many soybeans. For milk6 one co+ can produce , <<</ <<< liters of milk per year. $ co+ does need a bigger area than a plant does6 and therefore the results are not (ery surprising. $lthough the effects from different pesticides might ha(e an impact on the land #uality6 they +ere not taken into consideration. $ nonL$ discussion regarding the social (alue of farmland (ersus soybean culti(ation could be interesting in this contet.

cidification $ccording to the "* 2<<) database6 the acidification from soy milk production is 16/2 g SD2e#ui(alents6 as sho+n in Figure 4. !his mainly comes from the soy milk manufacturing phase6 +hich stands for almost )3= of the total acidification. !he production of the package stands for 1<= +hile the use phase contributes +ith 1)=. ;ithin the soy milk manufacturing6 the processes connected to the culti(ation of the soybeans and the transports contribute most to the acidification.

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Figure 4. $cidification for soy milk

!he acidification for the regular milk production is 1< g SD2e#ui(alents 71<8. !he largest o(erall contribution comes from emissions from the dairy farm6 and ammonia is the element that accounts for the main part of the total acidification.

Eutrophication !he soy milk contributes to eutrophication +ith 161% g *D4 e#ui(alents +hich can be con(erted into g ID3 e#ui(alents by using the generic "* factors @1 *D4 M <61 ID3A 7118. !he largest contributor of ID3e#ui(alents from soy milk is the soybean manufacturing. -ore than ,%= of the eutrophication impact comes from the manufacturing of soy milk according to Figure %. !he production of the package and the use phase together stand for the remaining 1%=.

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Figure 5. utrophication for soy milk

Drdinary milk contributes to the eutrophication +ith 3/ g ID3 e#ui(alents. $t the dairy farm the eutrophication is affected by emissions and leaching. !he con(entional farm feed production is the largest contributor 7128.

&ossil Energ" 'se For soy milk6 the total energy in the life cycle6 according to Sima*ro6 is 363) -:. !he largest part of this energy6 4/=6 comes from the manufacturing including the transports6 follo+ed by 2'= for the package and 2%= for the use phase. !his is seen in Figure '.

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Figure 6 . (ossil energy use for soy milk

For the total life cycle of one liter of regular milk6 data from t+o different sources +ere usedand a mean (alue +as calculated. !his +as done due to the (ery di(erse results in the sources. S(ensk -Nlk state that the fossil energy use is 36/ -:. ederberg6 on the other hand6 states that it is as lo+ as 26' -:. !he mean (alue6 362% -:6 +as used in the results for this report. Df the total energy use6 the farm production stands for nearly '<=6 the manufacturing of the packaging for 1%=6 the use6 burning6 disposal and recycling of the packaging as +ell as transports in bet+een these instances for the remaining 2% =.

Climate change limate change epressed in global +arming potential for soy milk is 21% g D2e#ui(alents6 see Figure ). !he largest contribution to climate change from soy milk is the energy used in soy milk manufacturing. &t stands for '< = of the total %, = of global +arming potential coming from the soy milk manufacturing processes. !he use phase contributes +ith 24 = and the production of the package stand for the remaining 1, = and nearly 4 = goes back in the system from the recycling of the package6 see Figure ).

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Figure 7 . )lobal warming potential for soy milk

$gricultural acti(ities are kno+n to add to the global +arming. $ccording to the &* agriculture is one of three main causes for the increase of green house gases 7138. !he farm in this study emits /<< g D2e#ui(alents per liter milk it produces. For con(entional milk the contribution to global +arming comes from6 in descending orderH -ethane6 Iitrous oide and arbon dioide. -ethane emissions originate in fermentation and manure management. Iitrous oide comes directly from manure and soil. !he carbon dioide is emitted by production and transports.

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(tratospheric o)one depletion !he soymilk has its largest contribution to oone layer depletion in the production of the package phase +ith '< = of the total of 3621< kg F11. Figure , sho+s the net+ork tree for the stratospheric oone depletion caused by soy milk and Figure / displays ho+ much each phase of the life cycle contributes. !here is no hotspot in the package production since this step consists of se(eral processes +ith no large contribution alone. )

Figure 8. )lobal warming potential for soy milk

!he oone depletion caused by con(entional milk is %6121< kg F11 and '4= originates from the dairy +ere transports are the largest contribution. !he transport bet+een farms and dairies is responsible for a third of the total effect. 3'= stratospheric oone affect comes from the farm. $t the farm fodder production is the main cause of the depletion. ,

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(ummari)ed results Table 3. +ummarized results according to impact category .

Results Land use $cidification "utrophication limate change "nergy use Done layer depletion

nit mOKl g SD2 e#Kl g ID3 e#Kl g D2 e#Kl -: kg F11Kl

Soy milk <6%/ 16/2 <611% 21% 363) 362 e)

Drdinary milk 16%a 1
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ederberg6 . FlysN 6 $. 2<<4. Life ycle in(entory of 23 dairy farms in South;estern S+eden. !he S+edish &nstitute for food and biotechnology6 b

-Nlkens milkNpP(erkan  S(ensk mNlk. httpHKK+++.s(enskmolk.seK&mageQaultK&magesKidR4/4KscopeR12,K&mageQaultCandler.asp

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$. Cospido6 -.!. -oreira6 G. Feioo6 2<<26 Simplified life cycle assessment of galician milk production

Figure 9. *ar graph showing the characterization of impact categories

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%.2. *iscussion and reflections General discussion Dne of the most important factors +hen considering the en(ironmental impact of soy milk is the choice of country farming the soybeansE different countries might ha(e (ery different farming routines6 +hich in turn could lead to rather different results in the en(ironmental impact assessment. $s one can see in the characteriation of the results6 the farming and transportation has the largest o(erall en(ironmental impact for nearly all impact categories6 something +hich +as epected. Co+e(er6 no impact assessment has been made +ith data from soy farming countries such as Belgium. !his +ould be an interesting addition to this study6 but has not been done6 due to the limitations in time. Something +hich is a source for discussion is the fact that the characteriations used for the different regular milk L$Hs are unkno+n. !his could make a crucial difference in the results6 and the proect group belie(es that a more complete study of regular milk should be used as a reference for the comparison. Finally6 the issue of nutrition should be discussed. &n this study6 one liter of each drink +as considered side by side. !his is only accurate if the drinks are merely considered as thirst #uenchers. Co+e(er6 if one takes the nutritional (alues of both drinks into account6 one +ould ha(e to drink nearly t+ice the amount of soy milk to get the same energy as from one liter of regular milk. Both drinks ha(e similar fat and protein (alues6 but to obtain the same amount of carbohydrates as one gets from milk6 %< times the amount of soy milk +ould ha(e to be consumed6 as stated in $ppendi 1. Iaturally6 this +ould ha(e a huge impact on data (alues if taken into account and might be interesting from a social point of (ie+. For instance6 +hat +ould happen if soy milk became so popular that it completely replaced regular milk ;ould children get enough calcium and other (ital minerals they need gro+ing up

*iscussion of specific impact results !he proect group argues that another important aspect to consider is the land use and the definition of the term >land use?. For soy milk6 the land use mainly comes from the soy bean culti(ation and the stubbed land that is a result of the culti(ation. !he meaning of stubbed land is deforestation of rainforests being transformed into soy plant fields6 +hich by many people might be seen as a maor en(ironmental impact6 compared to an open pasture +ith graing co+s. For regular milk6 the land use mainly comes from the farming of the animals. $ccording to the >-ilk and the "n(ironment? report from the S+edish airy $ssociation6 graing animals are absolutely necessary for ensuring that the di(ersified landscape in S+eden does not disappear. Furthermore6 the report states that se(eral animals and plant need graed land to sur(i(e. !hus6 the proect group feels that larger area needed for milk production seems reasonable. -oreo(er6 the group reasons that there in the future should be some kind of key factor for measuring the social issues of land use in addition to the ra+ en(ironmental impact. !he fact that the eutrophication is nearly 4<< times bigger for regular milk than that for soy milk @as sho+n in !able 3A seems peculiar. Since both soybean farming and dairy farming are agricultural acti(ities6 these should at least ha(e similar (alues to eutrophication. !he large number could in part be due to the culti(ation and gro+ing of co+ fodder. !hus6 a hypothesis

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is that the fertiliers and pesticides used for this are far greater in number than those used for the soy bean farming. !his +ould ha(e to be (erified for a more accurate result. $nother slightly surprising result is the fact that regular milk produces roughly four times more acidification than soy milk production. !he main contributor to acidification is often SD4 @from the combustion of oil and coalA6 +hich leads the proect group to the hypothesis that there may be far less machines used for soy bean farming than for co+ farming. &n addition to the oil used for the machine fuel6 some dairy farms could also be using oil for heating their facilities. $ more thorough analysis of the procedures for the t+o different drinks might gi(e more insight in the issue6 but could not be conducted6 due to limitations in time and resources. !he limate change factor @global +armingA is roughly three times larger for regular milk6 something +hich the proect group feels is slightly odd. ue to the large amounts of deforestation and the impact this has on the balance of carbon dioides in the atmosphere6 the proect group epected the figure for soy milk to be bigger. on(ersely6 a large number of scientists claim that the emissions of methane @+hich has a high D2e#ui(alent (alueA from the co+s are a large contributing factor to rising carbon dioide le(els. !his +ould be one eplanation +hy the figures are higher for regular milk6 but is not really a fully recognied fact6 and other scientists argue the en(ironmental impact of co+s9 emissions. $nother factor +hich could affect the climate change of regular milk is the culti(ation of the fodder used to feed the co+s. *erhaps the most intriguing result is that of the fossil energy use. Cere6 much larger figures +here epected for the soy milk6 mainly due to the etremely long distance the soybeans tra(el to the production site and the retail stores. !his leads the proect group to belie(e that the assumptions and calculations for the different transportations might not be entirely reliable. Co+e(er6 as pre(iously mentioned6 the dairy farms might use a larger number of machines for the farm +ork as +ell as heating systems for the keeping of the co+s. $lso6 regular milk needs to be cooled in all stages of its life cycle6 something +hich might use a lot of fossil energy. 0egarding the oone layer depletion6 the only main difference in the packaging is the aluminium in the soy milk package. Co+e(er6 this factor is so small that might not e(en be +orth optimiing.

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+. Conclusions !o make any general conclusions regarding the en(ironmental impact of regular milk (ersus soy milk is difficult6 especially due to the scant data a(ailable for soy milk production and not (ery detailed process descriptions in the regular milk studies. Co+e(er6 t+o specific conclusions ha(e been dra+n by the proect groupH •

For both drinks it is true that the actual farming is a maor factor in the en(ironmental impact and could probably be optimied in some areas

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Soy beans ha(e a larger >direct? en(ironmental impact6 due to deforestation and transformation of land. 0egular milk6 in turn6 has more long term impacts6 such as climate change6 acidification and eutrophication

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!ransports is a large contributor in all stages6 but is something +hich could probably be optimied

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ooling of drinks is a significant contributor to en(ironmental impact6 but could be a(oided for soy milk

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,. eferences 718 -ade Co+ @2<<)A. +oy Milk. 7Dnline8. $(ailableH httpHKK+++.madeho+.comKQolume%KSoy -ilk.html 72<
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ppendices Appendi) 1 * nutritional values

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Soy-milk-an-attributional-Life-Cycle-Assessment-examining-the-potential-environmental-impact-of-soy-milk.pdf

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