P.R. van Oel
A.Y. Hoekstra
July 2010

The green and blue water
footprint of paper products:
Methodological considerations
and quantification

Value of Water

Research Report Series No. 46

THE GREEN AND BLUE WATER FOOTPRINT OF PAPER PRODUCTS:
METHODOLOGICAL CONSIDERATIONS AND QUANTIFICATION

P.R. VAN OEL1
A.Y. HOEKSTRA2JULY 2010

VALUE OF WATER RESEARCH REPORT SERIES NO. 46

1
2

ITC, University of Twente, Enschede, The Netherlands, Pieter van Oel, oel@itc.nl

Water Engineering and Management Department, University of Twente, Enschede, The Netherlands,
a.y.hoekstra@utwente.nl© 2010 P.R. van Oel and A.Y. Hoekstra.

Published by:
UNESCO-IHE Institute for Water Education
P.O. Box 3015
2601 DA Delft
The Netherlands

The Value of Water Research Report Series is published by UNESCO-IHE Institute for Water Education, in
collaboration with University of Twente, Enschede, and Delft University of Technology, Delft.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in
any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the priorpermission of the authors. Printing the electronic version for personal use is allowed.

Please cite this publication as follows:
Van Oel, P.R. and Hoekstra, A.Y. (2010) The green and blue water footprint of paper products: methodologicalconsiderations and quantification, Value of Water Research Report Series No. 46, UNESCO-IHE, Delft, theNetherlands.

Contents
Summary................................................................................................................................................................. 5

1. Introduction ........................................................................................................................................................ 7
2. Method................................................................................................................................................................ 9
2.1 Estimating the water footprint of paper products......................................................................................... 9
2.2 Estimating the water footprint of paper consumption in a country ............................................................ 15
3. Results .............................................................................................................................................................. 17
3.1 The water footprint of paper products........................................................................................................ 17
3.2 The water footprint of paper consumption in the Netherlands................................................................... 20
4. Discussion......................................................................................................................................................... 23
5. Conclusion........................................................................................................................................................ 27

References ............................................................................................................................................................ 28

Summary
For a hardcopy of this report, printed in the Netherlands, an estimated 200 litres of water have been used. Water
is required during different stages in the production process, from growing wood to processing pulp into thefinal consumer product. Most of the water is consumed in the forestry stage, where water consumption refers to
the forest evapotranspiration. The water footprint during the manufacturing processes in the industrial stage
consists of evaporation and contamination of ground- and surface water. In this report we assess waterrequirements for producing paper products using different types of wood and in different parts of the world. We
quantify the combined green and blue water footprint of paper by considering the full supply chain; we do notinclude the grey water footprint in this study.
The water footprint of printing and writing paper is estimated to be between 300 and 2600 m3/ton (2-13 litres for
an A4 sheet). These figures account for the paper recovery rates as they currently are. The exact amount
depends on the sort and origin of the paper used for printing. Without recovery, the global average water
footprint of paper would be much larger; by using recovered paper an estimated 40% is saved globally. Further
saving can be achieved by increasing the recovery percentages worldwide. For countries with a low recovered
paper utilization rate a lot of room for reduction still remains. Some countries such as the Netherlands, Spainand Germany already use a lot of recovered paper. In addition, the global water footprint of paper can be
reduced by choosing production sites and wood types that are more water-efficient.

The findings presented in this report can be helpful in identifying the opportunities to reduce water footprints ofpaper consumption. This report also shows that the use of recovered paper may be very helpful in reducing
water footprints.

1. Introduction
Forests are renewable resources that are key to the production of paper, since the main ingredient of paper iswood pulp (cellulose). Next to their importance for paper, forests are important for the production of othergoods, such as timber and firewood, the conservation of biodiversity, the provision of socio-cultural services
and carbon storage. Forests also play a vital role in catchment hydrology. Deforestation and afforestation affecthydrological processes in a way that may directly influence water availability. It is for instance well establishedthat a reduction in runoff is expected with afforestation on grasslands and shrublands (e.g. Fahey and Jackson,
1997; Farley et al., 2005; Jackson et al., 2005; Wilk and Hughes, 2002).

Large amounts of freshwater are required throughout the supply chain of a product until the moment ofconsumption. For quantifying this amount, the water footprint concept can be used (Hoekstra and Chapagain,
2007b; 2008). The water footprint of a product is defined as the total amount of freshwater that is needed to
produce it. The water footprint can contain green, blue and grey components. The green component is thevolume of water evaporated from rainwater stored in or on the vegetation or stored in the soil as soil moisture.
The blue component refers to evaporated surface and ground water. The grey component is the volume ofpolluted ground- and surface water. An increasing number of publications on virtual-water trade and water
footprint of consumer products has emerged in recent years (Chapagain and Hoekstra, 2007; 2008; Chapagain etal., 2006a; 2006b; Gerbens-Leenes et al., 2009; Hoekstra and Chapagain, 2007a; 2007b; 2008; Hoekstra andHung, 2005; Liu and Savenije, 2008; Liu et al., 2008; 2007; Ma et al., 2006; Van Oel et al., 2009). So far, thewater footprint of paper products has not been studied in enough detail to reflect on its claims on water
resources. There are several product-specific issues that have to be addressed in order to come to a fairassessment of the water footprint of paper products. In this report the main issues are addressed and some ways
to deal with them are proposed and discussed.

In this report, a method for determining the water footprint of paper products at the national level is proposedthat takes into account both the forestry and the industrial stage of the production process. The scope is limited
to a study of consumptive water use – considering both the green and blue water footprint. We do not consider
the grey water footprint in this report. First, we estimate the water footprint of paper products produced using
pulp from the main pulp producing countries in the world. We take into account the use of recovered paper.
Second, a method for the quantification of the water footprint of paper products that are consumed in a specificcountry is presented and applied for the Netherlands.

2. Method
2.1 Estimating the water footprint of paper products

The water footprint during the forestry stage contains both a green and blue component. These two components
cannot easily be determined separately as trees use rainfall water and tap from groundwater resources
simultaneously. Therefore, in the scope of this study, we estimate the green and blue water footprint of paper
products as a total sum. During the industrial stage there is only a blue water footprint. The water footprint of apaper product p (expressed in m3/ton) is estimated as follows:
WF [ p ] = WF forestry [ p ] + WFindustry [ p ]The water footprint of a paper product for the forestry stage is estimated as follows:⎛ ET + (Ywood × f water ) ⎞WF forestry [ p ] = ⎜ a⎟ ⋅ f paper × f value × (1 − f recycling )
Ywood
⎝
⎠

in which ETa is the actual evapotranspiration from a forest/woodland (m3/ha/year), Ywood the wood yield from aforest/woodland (m3/ha/year), fwater the volumetric fraction of water in freshly harvested wood (m3/m3), fpaper thewood-to-paper conversion factor (i.e. the harvested volume needed to produce a metric ton of paper product(m3/ton), fvalue the fraction of total value of the forest which is associated with paper production (dimensionless)and frecycling the fraction of pulp derived from recycled paper (dimensionless). Note that the wood-to-paper
conversion factor relates to the so-called product fraction (fp, mass/mass) that is used in the standard calculationof a product water footprint (Hoekstra et al., 2009). The two parameters relate as follows:f paper =1
fp × ρ

with ρ being the density of harvested wood (ton/m3).

The water footprint of a paper product for the industrial stage is estimated as follows:
WFindustry [ p ] = E + R + P

in which E is the evaporation in the production process (m3/ton), R the water contained in solid residuals(m3/ton) and P the water contained in products (m3/ton).

10 / The green and blue water footprint of paper products

Step 1: Estimating evapotranspiration (ETa) by forest type and by country
There are several factors that influence evapotranspiration from forest biomes, including meteorologicalconditions, tree type and forest management. To get an overview of evapotranspiration from forests at the global
level, use is made of two data sources that are both obtained from FAO GeoNetwork (Figure 1):-

The World's Forests 2000 (FAO, 2001): this dataset is based on 1992-93 and 1995-96 AVHRR data andgives global distribution of forest biomes at a resolution of 1 km. Five different forest types are
distinguished: boreal (typical trees include pine, fir, and spruce), tropical (typical trees include eucalyptus),
sub-tropical, temperate (typical trees include oak, beech and maple) and polar forest. Different forest types
can be present in one country. For its low relevance, polar forests have been ignored.

-

Annual actual evapotranspiration (FAO, 2009b): this dataset contains annual average values for the period
1961-1990 at a resolution of 5 arc minutes.

Figure 1. Top: annual actual evapotranspiration (FAO, 2009b). The dataset contains yearly values for global land
areas for the period 1961-1990. Bottom: The World's Forests 2000 (FAO, 2001) This database is based on 199293 and 1995-96 AVHRR data.

The green and blue water footprint of paper products / 11

With these data it is possible to obtain a rough estimate of annual evapotranspiration values for forests in mostcountries of the world. Country averages are determined by averaging all values of actual evapotranspiration ina country for all locations that are covered with closed forest. For calculating the water footprint of paper
products, evapotranspiration values for the 22 main global producers of pulp (FAO, 2009a) are determined.
Together, these countries produced 95% of globally produced pulp for the period 1998-2007. The locations fromwhich wood is actually obtained remain unclear from statistics on pulp production. Therefore it is difficult torelate the right amount of evapotranspiration to the production of pulp. Due to a lack of detailed spatial
information, in this study ranges of possible evapotranspiration values are presented, rather than estimates for
actual forestry locations. Besides uncertainties on locations of origin within a producing country, also importfrom other countries may be important. Paper mills in Sweden, for example, use 75% of wood that originatesfrom Sweden itself; the other 25% is imported from Latvia, Estonia and Lithuania (Gonzalez-Garcia et al.,2009). These pre-processing international trade flows are not taken into account in this study.

Table 1 shows the average annual evapotranspiration for the main pulp producing countries by forest type. If
only one forest type exists in a country, only one value will be considered. If more than one forest type exists,
the values of all forest types are given. For large countries covering several climatic zones, such as the USA,values of evapotranspiration may vary considerably.

Table 1. Contribution to annual pulp production and estimates for average actual annual evapotranspiration by
forest type in the main pulp-producing countries.
Average actual annual evapotranspiration by forest type(mm/year)**BorealTemperate
SubtropicalTropicalContribution to
global pulp
production*

Share ofchemical pulp*

USA

29.5%

85%

278

516

Canada

13.5%

52%

358

360

-

-

China

9.2%

11%

370

416

608

547

Finland

6.5%

60%

355

293

-

-

Sweden

6.3%

69%

345

318

-

-

Japan

5.9%

87%

-

637

725

1048

Pulp producing
country

635

1730

Brazil

4.8%

93%

-

-

965

Russia

3.3%

74%

310

362

-

-

Indonesia

2.4%

93%

-

-

-

1071

India

1.7%

37%

-

-

455

551

Chile

1.6%

86%

-

567

578

-

France

1.3%

67%

-

401

386

-

Germany

1.3%

44%

-

363

-

-

Norway

1.2%

26%

328

303

-

-

Portugal

1.0%

100%

-

512

502

-

Spain

1.0%

93%

-

547

527

-

South Africa

1.0%

72%

-

-

819

762

Austria

0.9%

76%

-

344

-

-

New Zealand

0.8%

45%

-

491

630

-

Australia

0.6%

50%

-

768

775

818

Poland

0.6%

76%

-

377

-

-

Thailand

0.5%

86%

-

-

-

636

Total

94.8%

* Data source: annual averages for the period 1996-2005 based on FAOSTAT data (FAO, 2009a).
** Data sources: national averages estimates based on grid data from FAO (2001; 2009b).

12 / The green and blue water footprint of paper products

Step 2: Estimating wood yield (Ywood)
For this study it has been assumed that the wood used for the production of wood pulp is harvested at a rate
corresponding to the maximum sustainable annual yield from productive forests with wood production as its
primary function. We will reflect upon this approach in the discussion section. Data on wood products are
obtained from the Global Forest Resources Assessment 2005 (FAO, 2006). The estimates used in this study arepresented in Table 2. Tree types are categorized into pine, eucalyptus and broadleaves. In this study thefollowing assumptions are made for tree types in different forest biomes:-

Boreal forests yield pine-

Temperate forests yield broadleaves and pine-

Subtropical and tropical forests yield eucalyptus

Table 2. Wood yield estimates for the main pulp-producing countries.
3

Pulp producing country

Wood yield estimates (m /ha/year)*
Broadleaves

Eucalyptus

Pine

USA

7***

16***

6

Canada

7***

China

6

Finland7

6

Sweden

7**

8**

Japan

11

14

Brazil20

45

Russia7***

Indonesia

6**
6

4

7**
8***

19

India

10

Chile

22

26

19

France

7**

16**

9

Germany

7**8**Norway7**

8**Portugal

7**

16**

8**

Spain

7**

16**

8**

South Africa

1123

Austria7**

New Zealand

14

19**

15

Australia

14**

19

12

Poland8

Thailand

8**

7
14**

* Data source: FAO (2006).
** Continental averages from available data are assumed.
*** European continental averages are used. In the case of Canada and the United States this is due to a lack of available data.
For Russia, a European average is assumed to be more representative than the Asian continental average.

Step 3: Fraction of water in harvested wood (fwater)
Generally this fraction is around 0.4 m3 of water per m3 of freshly harvested wood (Gonzalez-Garcia et al.,2009; NCASI, 2009). A large part of the water may be returned to surface or ground water during the industrial
manufacturing process. It is however removed from the forest area and should therefore be accounted for in thewater footprint in the forestry stage.

The green and blue water footprint of paper products / 13

Step 4: Wood-to-paper conversion factors (fpaper)This is the amount of wood needed to produce a certain mass of paper product (m3/ton). Estimates for important
products are obtained from the UNECE conversion factors report (UNECE/FAO, 2010). The main conversion
factors are summarized in Table 3. The product categories used in this study are based on the categories as usedin the ForestSTAT database (FAO, 2009a). For different kinds (and qualities) of paper different types of pulp
are used. The pulp differs according to the type of pulping technique that is applied. In this study no differences
are made for different tree types.

Table 3. Wood-to-paper conversion factors.
Product
Mechanical Wood Pulp

FAO product code
(FAO, 2009a)
1654

ITC product group codes used
(ITC, 2006)
2512

Conversion factors based on
3
UNECE/FAO (2010) (m /ton)
2.50
2.67

Semi-Chemical Wood Pulp

1655

25191

Chemical Wood Pulp

1656

2514, 2515, 2516

4.49

Dissolving Wood Pulp

1667

2513

5.65

Recovered Paper

1669

2511

Newsprint

1671

6411

2.87

Printing & Writing Paper

1674

6412, 6413

3.51

Other Paper & Paperboard

1675

6414, 6415, 6416, 6417, 6419, 642

3.29

Step 5: Estimating the fraction of total value of the forest associated with paper production (fvalue)
Forests generally serve multiple functions, one of which may be the production of paper products. Others may
be the production of timber, biodiversity conservation and carbon storage. Therefore, not all evapotranspirationfrom a forest should necessarily be attributed to the production of paper products. A value fraction (Hoekstra etal., 2009) could be determined to allocate the amount of water to be allocated to the production of wood pulp for
a forest with n functions, including the production of wood pulp:

f value [ pulp ] =value [ pulp ]n∑ value [i ]i =1

In this study it is assumed that paper is produced from forests that have wood production as the primary function
and for which annual growth is equal to annual harvest, so we assume the value fraction to be equal to 1. We
will come back to this issue in the discussion section.

Step 6: Estimating the fraction of pulp derived from recovered paper (frecycling)
Recycling is an important factor for the water footprint, because fully recycled paper avoids the use of freshwood and thus nullifies the water footprint in the forestry stage. When more recovered paper is used, the overallwater footprint will decrease. On average an estimated 41% of al produced pulp is obtained from recycled paper(FAO/CEPI, 2007; UNECE/FAO, 2010), with large differences between producers using no recycled paper at
all to producers that achieve relatively high percentages. We obtained the ‘recovered paper utilization rates’ forthe main pulp producing countries from FAO/CEPI (2007). The ‘recovered paper utilization rate’ is the amountof recovered paper used for paper and paperboard as a percentage of paper and paperboard production. Losses in
repulping of recovered paper are estimated to be between 10 and 20 percent (FAO/CEPI, 2007). In this study, 15

14 / The green and blue water footprint of paper products

percent is used for all countries. The values used in this study are summarized in Table 4. The productcategories for which recycling is taken into account are only the consumer product categories (i.e. newsprint,‘printing & writing paper’ and ‘other paper & paperboard’), since these are the only categories for which it isactually used.

Table 4. Recovered paper utilization rates and frecycling for the main pulp-producing countries.
Country

Recovered paper utilization rate*

USA

0.37

Fraction of pulp derived fromrecycled paper (frecycling)**
0.31

Canada

0.24

0.20

China

0.42*

0.36

Finland

0.05

0.04

Sweden

0.17

0.14

Japan

0.61

0.52

Brazil0.40

0.34

Russia0.42***

0.36

Indonesia

0.42***

0.36

India

0.42***

0.36

Chile

0.42

0.36

France0.60

0.51

Germany

0.67

0.57

Norway0.22

0.19

Portugal

0.21

0.18

Spain

0.85

0.72

South Africa

0.42***

0.36

Austria

0.46

0.39

New Zealand

0.25

0.21

Australia

0.64

0.54

Poland0.36

0.31

Thailand

0.59

0.50

Average of main pulp producing countries

0.42

0.36

Netherlands* Data source: FAO/CEPI (2007).

0.70

0.60

** 85% of recovered paper utilization rate assumed due to loss in processing.
*** When no data are available for the individual country, the average of the other countries is used.

Step 7: Estimating the water footprint of paper products in the forestry stage
For a quantification of the water footprint of paper products in the forestry stage, estimates for the main pulp
producing countries are made, as listed in Table 1.

Step 8: Estimating the water footprint of paper products in the industrial stage
The water footprint of paper products in the industrial stage of production is estimated based on the case of theUSA, considering the country’s paper and pulp production sector as a whole (NCASI, 2009). The USA is thelargest producer of paper pulp and is assumed to be representative for the global paper industry. In this study nocomparison is made between different techniques and processes that may be used in producing pulp.

The green and blue water footprint of paper products / 15

2.2 Estimating the water footprint of paper consumption in a country

Many countries strongly depend on imports of pulp and paper. For those countries it is relevant to know thewater footprints of the imported products and where these water footprints are located. This will be shown in acase study for the Netherlands. As a basis, we use data on the annual production, import, export andconsumption of paper for the Netherlands as shown in Table 5.

Table 5. Annual production, import, export and consumption for the Netherlands for the period 1996-2005.
Product

Printing & writing
paper
1674

Other paper &paperboard
1675

3877008954001987200

47654012678901498200

3223402594801143450

1417900

93587060476010198402067500

Pulp

Newsprint

1654-56, 1667

1671

Production (ton/year)*

125350

Import quantity (ton/year)*1132860

Export quantity (ton/year)*
Consumed (ton/year)* Source: ForestStat (FAO, 2009a).

FAO code

A weighted average for all import partners is made for a few different paper products, similar to the way it isdone by van Oel et al. (2009) and Hoekstra et al. (2009). Data on imports specified by trade partner are usedfrom the International Trade Centre (ITC, 2006). Table 3 shows the product categories used for estimating thewater footprints of imported paper products. The average water footprint WF* of a paper product p consumed in
the Netherlands (NL) is estimated by assuming that:m

WF *[ NL, p ] =P[ NL] × WF [ NL, p ] + ∑ ( I [c] × WF [c, p ])c =1
m

P[ NL] + ∑ I [c ]c =1

in which WF[NL,p] is the water footprint of paper product p produced in the Netherlands using Dutch pulp;
WF[c,p] the water footprint of paper product p produced in the Netherlands using pulp from country c; P[NL]
the production of wood equivalents in the Netherlands, and I[c] the import of wood equivalents into theNetherlands from country c. The various sorts of pulp produced in and imported into the Netherlands are
expressed in wood equivalents using the conversion factors as shown in Table 3. The assumption here is that
paper products are based on domestic and imported pulp according to the ratio of domestic pulp production topulp import. On the Dutch market, in the period 1996-2005, 6% of the available pulp (expressed in terms ofwood equivalents) had domestic origin; the remaining 94% was imported.

3. Results
3.1 The water footprint of paper products

The evapotranspiration per volume of harvested wood for the main pulp producing countries is shown in Table
6. The water footprint of paper products is shown in Tables 7-9. Country-specific recycling percentages areincorporated in these values. The lowest estimate for printing & writing paper is 321 m3/ton (eucalyptus fromsubtropical biome in Spain) and the highest value is 2602 m3/ton (eucalyptus from tropical biome in the USA),corresponding to 2 and 13 litres per sheet of standard A4 copy paper respectively. If no recovered paper would
have been used, these values would become 753 m3/ton (eucalyptus from subtropical biome in Brazil) for the
lower estimate and the higher estimate would be 3880 m3/ton (eucalyptus from subtropical biome in China). For
one sheet of A4 copy paper this means 4 and 19 litres respectively.
Table 6. Water footprint of harvested wood for the main pulp-producing countries.
33

Eucalyptus from
Subtropical biome

Eucalyptus from
Tropical biome

397

1081

1105

995

USA

463

860

Canada

597

600

525

China

891

1001

693

Finland

592

488

451

Sweden

413

381

463

859

571

434

528

Pulp producing
country

Pines from
Temperate biome

752

Pines from Boreal
biome

Broadleaves from
Temperate biome

Water footprint for different trees and places of origin (m /m )Japan
BrazilRussia

527
214

371

Indonesia

564

India

455

Chile

298

262

222

France

446

584

241

Germany435

529

Norway363

442

Portugal

613

746

314

Spain

655

797

329

393

Austria

412

501

New Zealand

335

351

338

Australia

662

549

415

Poland539

459

South Africa

Thailand

233

356

551

331

438
463

18 / The green and blue water footprint of paper products
Table 7. Water footprint of newsprint (m3/ton), taking into account country-specific recovered paper utilization
rates.
Country
USA

Pine from boreal
biome
912

Pine fromtemperate biome
1692

Broadleaf fromtemperate biome
1479

Canada

1363

1371

1199

China

1648

1852

1282

Finland

1626

1342

1239

Sweden

1015

935

1138

1187

789

802

976

Japan
BrazilRussia

Eucalyptus fromsubtropical biome
781

Eucalyptus fromtropical biome
2127

2045

1840

729
406

687

Indonesia

1043

India

842

Chile

551

483

410

France

627

822

339

Germany

537

654

Norway

441

847

1030

Portugal

917

1446

1759

740

Spain

522

635

262

720

876

South Africa

659

Austria
New Zealand

757

793

763

Australia

866

718

543

Poland1073

914

Thailand

1019

613

573
662

Table 8. Water footprint of ‘printing & writing paper’ (m3/ton), taking into account country-specific recovered paper
utilization rates.
Country
USA

Pine from boreal
biome
1115

Pine fromtemperate biome
2069

Broadleaf fromtemperate biome
1809

Canada

1667

1676

1466

China

2015

2266

1568

Finland

1988

1641

1515

Sweden

1241

Japan

1144

1392

1452

965

981

1193

BrazilRussia

Eucalyptus fromsubtropical biome
955

Eucalyptus fromtropical biome
2602

2501

2250

891
497

840

Indonesia

1275

India

1029

Chile

674

591

502

France

766

1005

415

Germany

657

799

Norway1036

1260

Portugal

1769

2151

Spain

1121

638

776

South Africa
Austria

321
806

881

1246

905
749

1072

New Zealand

925

969

933

Australia

1060

878

665

Poland1312

1118

Thailand

540

701
809

The green and blue water footprint of paper products / 19
Table 9. Water footprint of ‘other paper & paperboard’ (m3/ton), taking into account country-specific recovered
paper utilization rates.
Country
USA

Pine from boreal
biome
1045

Pine fromtemperate biome
1940

Broadleaf fromtemperate biome
1696

Canada

1563

1571

1374

China

1889

2124

1470

Finland

1864

1538

1420

Sweden

1163

1072

1304

1361

904

920

1119

Japan

Eucalyptus fromsubtropical biome
895

Eucalyptus fromtropical biome
2439

2344

2109

835

BrazilRussia466
787

Indonesia

1195

India

965

Chile

631

554

470

France

718

942

389

Germany616

749

Norway971

1181

Portugal

1658

2017

848

Spain

598

728

301

1051

826

1004

South Africa
Austria

506

755

New Zealand

867

909

874

Australia

993

823

623

Poland1230

1048

Thailand

1168

702

657
759

Water footprint of paper products in industrial stage – example USA
In the USA, annual industrial production of paper products is around 97×106 ton/year. The total water use for themain water consumption categories is: E = 507×106 m3, R = 19×106 m3, P = 10×106 m3 (Figure 2). A roughestimate then gives an average value of 5.5 m3/ton for a paper product.

Return flow to surface water
6
35144×10 m
Return flow to groundwater
30m

Surface water
6
34736×10 m
Groundwater
6
3
787×10 m
Water in wood
6
3
145×10 m
Other water inputs
63
8×10 mIncluded in WFIndustry

Industrial processes
Production of pulp and paper products
6
97×10 ton

Recycling 5×10 m
63

Evaporation
63
507×10 m
Water in solid residuals
63
19×10 mWater in products
63
10×10 mFigure 2. Water flows in the paper and pulp industry in the USA (NCASI, 2009).

20 / The green and blue water footprint of paper products

3.2 The water footprint of paper consumption in the Netherlands

The Dutch water footprint related to the consumption of paper products is significant if compared to thefootprint related to the consumption of other products. The water footprint of paper products is estimated toconstitute 8-11% of the total water footprint of Dutch consumption (Van Oel et al., 2009). Figure 3 gives asummary of the water footprint accounts for the Netherlands insofar related to paper consumption, production
and trade. Minimum and maximum estimates are given to account for the fact that paper products in the
countries of origin can have a low or high water footprint depending on the biome from which the wood isderived (Tables 7-9).

Table 10 shows the water footprint of paper products in the Netherlands, whereby a distinction is made between:(i) paper produced from trees grown in the Netherlands, (ii) imported paper to the Netherlands or paper
produced from imported pulp, and (iii) the weighed average. The water footprint of paper products produced
from trees grown in the Netherlands is substantially lower (two to three times) than that of imported paper or
paper produced from imported pulp. Most of the imported pulp originates from other European countries (85%),
followed by North America (12%) (Figure 4).

If countries from which the Netherlands import pulp and paper would not recover paper as they currently do(Table 4) and if also the Netherlands itself would not recover paper, the water footprint of paper products
consumed in the Netherlands would be 4.9-7.1 Gm3/yr. Using recovered paper according to current rates has
thus resulted in a water saving of 36%. For the Netherlands, the water footprint of a standard A4 copy paper (80gram/m2) is between 5 and 7 litres (7-10 litres if no recovered paper is used).

Ve, r
Ve, d
Ve
3
3
3
Min 1.8Gm + Min 0.0Gm = Min 1.8Gm
3
3
3
Max 2.9Gm
Max 0.0Gm
Max 2.9Gm
+

+

Ve,r

+
WFcons,nat,ext
WFcons,nat,int

WFcons,nat==

WFcons,nat,ext
WFcons,nat,int
WFcons,nat3
3
3
Min 3.1Gm + Min 0.1Gm = Min 3.2Gm
3
3
3
Max 4.5Gm
Max 0.1Gm
Max 4.6Gm
=

Ve

Ve,d

Vi
Vb
WFarea,nat
3
Min 4.9Gm + Min 0.1Gm3 = Min 5.0Gm3
3
3
3
Max 7.4Gm
Max7.5Gm
Max 0.1Gm

ViWFarea,nat

Vb

Figure 3. Summary of the water footprint accounts for the Netherlands insofar related to paper consumption,
production and trade: virtual-water import (Vi), virtual-water export (Ve), the water footprint within the area of thenation (WFarea,nat) the water footprint related to national consumption (WFcons,nat), the external water footprint(WFcons,nat,ext), the internal water footprint (WFcons,nat.int), the virtual-water re-export (Ve,r) and the virtual-water
export from domestic production (Ve,d). The numbers in the boxes are minimum and maximum estimates for theperiod 1996–2005.

The green and blue water footprint of paper products / 21

Table 10. Water footprint of paper products in the Netherlands.
3

Water footprint (m /ton)

OriginPaper produced from trees grown in the Netherlands

Lower estimate
369

410

Printing & writing paper

451

501

Other paper & paper board

423

470

Newsprint

829

1144

994

1402

848

1267

Imported paper to the Netherlands or paper produced fromPrinting & writing paper
imported pulp
Other paper & paper board
Average paper as on the Dutch market*

Higher estimate

Newsprint

Newsprint

802

1101

Printing & writing paper

962

1349

Other paper & paper board

823

1221

* For the production of these products in the Netherlands it is assumed that pulp is used from imported and domestic sourcesin the same ratio as they are available (imported + produced). Around 94% of the available pulp in the Netherlands is imported.

Figure 4. Virtual-water imports to the Netherlands by continent related to the import of pulp and paper.

4. Discussion
Allocation of forestry evapotranspiration to harvested wood. The water footprint is an indicator that takes into
account the total use of freshwater for the production of a product. In the case of paper production from woodfrom a forest, it is not immediately clear what approach can best be chosen. Wood is harvested only after anumber of years of growth. One could thus consider the evapotranspiration over the whole period from planting
a forest until cutting it down and attribute that total evapotranspiration to the harvested wood. In practice,
however, at a bit larger spatial scale, one can consider harvesting as an annual activity. Assuming a more or lessstable demand for forestry products and a reasonable extent of sustainable forestry management practices, arational approach is to relate the average annual evapotranspiration from the forest to the maximum sustainableannual yield. The maximum sustainable annual yield is the maximum annual yield that can be obtained for an
infinite period of time. When actual yields from a forest are lower than the maximum sustainable annual yield(e.g. incidental wood harvesting in a non-production forest), it would be fair to attribute only a fraction of theannual evapotranspiration from the forest to the harvested wood, since the primary function of the forest isapparently other than for wood production. The fraction could be taken equal to Yact/Ymax. In the case of a forest
harvested according to the maximum sustainable annual yield (Ymax), we would take forest-ET over Ymax. In thecase of a forest with an actual yield Yact, we would take the fraction Yact/Ymax times the forest-ET over Yact,
which results in the same water footprint estimate as in the case of the forest harvested at maximum sustainableannual yield. This illustrates the fact that the actual yield does not really influence the water footprint of theharvested wood. The two key factors are forest-ET and the rate of wood growth (Ymax).
Allocation of forestry evapotranspiration to harvested wood (2). There is another issue of allocation. Woodlands
like semi-natural forests and plantations often serve purposes of considerable importance next to that ofdelivering wood for the production of paper. Next to the production of timber, important examples are
biodiversity conservation and carbon storage. The appropriate way of accounting is to allocate the forest-ET
over the various forest functions according to their economic value (Hoekstra et al., 2009). One would needestimates of the various values of forests, as for instance reported in Costanza et al. (1997). In this report wehave not included the other values of a production forest. We have attributed the full forest-ET to the primary
output of a production forest: wood.

Wood yields. Per biome we have estimated the maximum sustainable annual yield by assuming one typical tree
type. In reality, many forest biomes are mixed with regard to tree types. For a boreal forest biome, pine trees
have been assumed when taking data for the maximum sustainable annual yield, which is not precisely the casefor all areas that are classified as boreal biome. For temperate, subtropical and tropical biomes, tree diversity
may be even more diverse. Since actual evapotranspiration estimates are used for biomes rather than for specifictree types, this may cause inaccuracies.

Distinction between green and blue water. The green and blue water footprint requirements have been
determined jointly. The difference between the use of green and the use of blue water is not as straightforward
for forestry products as it is for other (agricultural) products. This difficulty is related to the process of water24 / The green and blue water footprint of paper products

uptake by trees. The extent of the root zone of a full grown tree is generally well beyond the rainwater that iscontained in the soil. Trees obtain water from the soil as well as from aquifers. More detailed studies are
required to make a reliable estimate of the ratio green/blue in the water footprint of forestry products.

Why measure green water footprint? Traditional measurements of water use focus on blue water and exclude
green water, so one may ask why include green water? Blue water scarcity is known because in several placeson earth groundwater tables decline and rivers run dry. Both forestry and agriculture, however, strongly dependon green water. Also rainwater is scarce, although in a less obvious way. The water footprint indicator isdesigned to feed the debate on how limited freshwater resources are allocated over different purposes, similar to
how the ‘ecological footprint’ is used to feed the debate on how we use the Earth’s scarce productive lands(Rees, 1992; Hoekstra, 2009). The purpose of the green water footprint is to measure human’s appropriation of
the evaporative flow, just like the blue water footprint aims to measure human’s appropriation of the runoff
flow. The green water footprint measures the part of the evaporated rainwater that has been appropriated forcertain human purposes and is therefore not available for other human purposes or nature. Green water used for
production forest is not available for crop production or natural forest in the same place. The water footprint of a
product thus shows the ‘water allocated’ to that product.

Why measure consumptive water use instead of water withdrawal? Industries are used to measure blue water
withdrawals (Gleick, 1993; Van der Leeden, 1990), not consumptive blue water use as we do in the current
study. Consumption refers to the part of the water withdrawal that really gets lost through evaporation, i.e. thepart of the water withdrawal that does not return to the system from which it was withdrawn. If one is interested
in the effect of water use at catchment scale, consumptive water use is a more meaningful indicator than water
withdrawal, since generally the largest fraction of the water abstracted returns to the system and can be reused.
The choice to look at consumptive water use explains why the ‘blue water footprint’ in the industrial stage of
paper production found in this study is much lower than the figures on ‘water use’ generally reported by paperindustries.

Grey water. The grey water footprint is not accounted for in this study. It is possible to produce paper without
polluting water resources, which is achieved when effluents have a quality that is equal to or better than theintake water quality. Such a clean production process requires advanced purification techniques and is not yet
applied in many production regions. Lack of worldwide data on both the quality of effluents and water bodies
affected made it impossible to give reliable estimates for the grey water footprint of paper products.

Variability in time. In estimating the water footprints of paper products, we have not considered annual
variations or changes over a longer period of time. For evapotranspiration, climate averages have been used (forthe period 1961-1990). Including annual variations would raise practical difficulties, since it can take many
years from the period of wood growth to the moment of consumption of the final paper product.

Allocation in the case of recovered paper. When recovered paper is used, a question is: how much of the water
footprint in the forestry stage of the original wood should be allocated to the paper made in first instance, howThe green and blue water footprint of paper products / 25

much to the paper made in the second round, how much to the paper in the third round, etc.? This issue becomes
more complex due to the fact that paper products are often a mixture of wood pulp and pulp from recycled
paper. The most simple solution is to fully allocate the water footprint in the forestry stage to the paper made in
first instance. Then, pulp from recycled paper has no forestry-related water footprint. The water footprint of
paper produced partly from wood pulp and partly from recycled paper-pulp can be calculated by weighing thewater footprints of the two different sorts of pulp according to their relative input. An argument for such asimple calculation scheme is that beforehand it is not known how many times (if at all) a paper product will berecycled, so that there is little other choice than fully allocating the water footprint of wood pulp to the paper
product that is directly made from it. If, however, one would be able to precisely trace recycling flows, one
could also allocate the water footprint in the first stage of wood production to the final paper products producedin the different recycling stages, so that (decreasing) fractions of the forestry-related water footprint areallocated to the paper products in the subsequent recycling stages. The current study is a macro study, where we
allocated the total annual water footprint in the forestry stage of paper production to the total annual paper
production, whereby the latter is partly based on recycled paper. This method calculates an average water
footprint of paper, which is good as an average and insensitive to the above-discussed allocation problem. If one
would be interested, however, in the water footprint of a specific piece of paper, coming from a specific paper
mill using a specific mixture of wood pulp and recycled paper-pulp, one would need to be explicit about thewater footprint of the wood pulp versus the water footprint of the recycled paper-pulp. We would argue fortaking the simple solution as proposed above.

Scope of study. Several processes that potentially contribute to the water footprint of paper products have been
ignored. We have only included the water footprint of wood growth and paper processing; we have excluded thewater footprint of other inputs (machineries, materials and energy) used in the process of making the final paper
product and getting it to the consumer. One important process that may contribute substantially is related totransportation. For transportation a variety of alternative sources of energy may be used, including fossil fuelsand bioenergy. Particularly when bioenergy is involved, the water footprint in transportation may be substantial(Gerbens-Leenes et al., 2009).

5. Conclusion
The water footprint of printing and writing paper is estimated to be between 300 and 2600 m3/ton (2-13 litres for
an A4 sheet). In these figures we have already accounted for the paper recovery rates as they currently are(Table 5). Without recovery, the global average water footprint of paper would be much larger; by using
recovered paper an estimated 40% is saved globally. Further saving can be achieved by increasing the recovery
percentages worldwide. For countries with a low recovered paper utilization rate a lot of room for reduction still
remains. Some countries such as the Netherlands, Spain and Germany already use a lot of recovered paper. In
addition, the global water footprint of paper can be reduced by choosing production sites and wood types thatare more water-efficient.

For the Netherlands, the water footprint related to the consumption of paper products is significant. The water
footprint of paper products is estimated to constitute 8-11% of the total water footprint of Dutch consumption.

References
Chapagain, A.K. and Hoekstra, A.Y. 2007. The water footprint of coffee and tea consumption in the
Netherlands. Ecological Economics, 64(1): 109-118.
Chapagain, A.K. and Hoekstra, A.Y. 2008. The global component of freshwater demand and supply: anassessment of virtual water flows between nations as a result of trade in agricultural and industrial
products. Water International, 33(1): 19-32.
Chapagain, A.K., Hoekstra, A.Y. and Savenije, H.H.G. 2006a. Water saving through international trade of
agricultural products. Hydrology and Earth System Sciences, 10(3): 455-468.
Chapagain, A.K., Hoekstra, A.Y., Savenije, H.H.G. and Gautam, R. 2006b. The water footprint of cotton
consumption: An assessment of the impact of worldwide consumption of cotton products on the water
resources in the cotton producing countries. Ecological Economics, 60(1): 186-203.
Costanza, R., dArge, R., de Groot, R., Farber, S., Grasso, M., Hannon, B., Limburg, K., Naeem, S., Oneill, R.V.,
Paruelo, J., Raskin, R.G., Sutton, P. and Van den Belt, M. 1997. The value of the world's ecosystemservices and natural capital. Nature, 387(6630): 253-260.
Fahey, B. and Jackson, R. 1997. Hydrological impacts of converting native forests and grasslands to pine
plantations, South Island, New Zealand. Agricultural and Forest Meteorology, 84(1-2): 69-82.
FAO. 2001. The World's Forests 2000: resolution of 1 km, based on 1992-93 and 1995-96 AVHRR data. Foodand Agricultural Organization, Rome, Italy.
FAO. 2006. Global Forest Resources Assessment: progress towards sustainable forest management 2005, Foodand Agriculture Organization, Rome, Italy.
FAO. 2009a. ForestSTAT. Food and Agriculture Organization, Rome, Italy.
FAO. 2009b. Global map of yearly actual evapotranspiration: resolution 5 arc minutes, for the period 19611990. Food and Agriculture Organization, Rome, Italy.
FAO/CEPI. 2007. Recovered paper data 2006. K1846/E, Food and Agriculture Organization, Rome, Italy.
Farley, K.A., Jobbagy, E.G. and Jackson, R.B. 2005. Effects of afforestation on water yield: a global synthesis
with implications for policy. Global Change Biology, 11(10): 1565-1576.
Gerbens-Leenes, W., Hoekstra, A.Y. and van der Meer, T.H. 2009. The water footprint of bioenergy.
Proceedings of the National Academy of Sciences, 106(25): 10219-10223.
Gleick, P.H. (ed.) 1993. Water in crisis: A guide to the world’s fresh water resources, Oxford University Press,
Oxford, UK.
Gonzalez-Garcia, S., Berg, S., Feijoo, G. and Moreira, M.T. 2009. Environmental impacts of forest production
and supply of pulpwood: Spanish and Swedish case studies. International Journal of Life Cycle
Assessment, 14(4): 340-353.
Hoekstra, A.Y. 2009. Human appropriation of natural capital: A comparison of ecological footprint and water
footprint analysis. Ecological Economics, 68(7): 1963-1974.
Hoekstra, A.Y. and Chapagain, A.K. 2007a. The water footprints of Morocco and the Netherlands: Global water
use as a result of domestic consumption of agricultural commodities. Ecological Economics, 64(1): 143-151.
Hoekstra, A.Y. and Chapagain, A.K. 2007b. Water footprints of nations: Water use by people as a function of
their consumption pattern. Water Resources Management, 21(1): 35-48.

30 / The green and blue water footprint of paper products
Hoekstra, A.Y. and Chapagain, A.K. 2008. Globalization of water, sharing the planet's freshwater resources.
Blackwell Publishing, Malden, USA.
Hoekstra, A.Y., Chapagain, A.K., Aldaya, M.M. and Mekonnen, M.M. 2009. Water footprint Manual: state of
the art 2009, Water Footprint Network, Enschede, the Netherlands.
Hoekstra, A.Y. and Hung, P.Q. 2005. Globalisation of water resources: international virtual water flows in
relation to crop trade. Global Environmental Change Part A, 15(1): 45.
ITC. 2006. Statistics International Trade Centre, SITA - Statistics for International Trade Analysis. International
Trade Centre. www.intracen.org/mas/sita.htm.
Jackson, R.B., Jobbagy, E.G., Avissar, R., Roy, S.B., Barrett, D.J., Cook, C.W., Farley, K.A., le Maitre, D.C.,
McCarl, B.A. and Murray, B.C. 2005. Trading water for carbon with biological sequestration. Science,
310(5756): 1944-1947.
Liu, J. and Savenije, H.H.G. 2008. Food consumption patterns and their effect on water requirement in China.
Hydrology and Earth System Sciences, 12(3): 887-898.
Liu, J.G., Yang, H. and Savenije, H.H.G. 2008. China's move to higher-meat diet hits water security. Nature,454(7203): 397-397.
Liu, J.G., Zehnder, A.J.B. and Yang, H. 2007. Historical trends in China's virtual water trade. Water
International, 32(1): 78-90.
Ma, J., Hoekstra, A.Y., Wang, H., Chapagain, A.K. and Wang, D. 2006. Virtual versus real water transfers
within China. Philosophical Transactions of the Royal Society B-Biological Sciences, 361(1469): 835-842.
NCASI. 2009. Water profile of the United States forest products industry (NCASI), National Council for Air
and Stream Improvement, National Triangle Park, NC: National Council for Air and Stream Improvement.
Rees, W.E. 1992. Ecological footprints and appropriated carrying capacity: what urban economics leaves out.
Environment & Urbanization, 4(2): 121.
UNECE/FAO. 2010. Forest product conversion factors for the UNECE region. Geneva Timber and Forest
Discussion Paper 49, United Nations Economic Commission for Europe, Food and Agriculture
Organization of the United Nations, Geneva, Switzerland.
Van der Leeden, F., Troise, F.L. and Todd, D.K. 1990. The water encyclopedia, Second edition, CRC Press,
Boca Raton, Florida, USA.
Van Oel, P.R., Mekonnen, M.M. and Hoekstra, A.Y. 2009. The external water footprint of the Netherlands:
Geographically-explicit quantification and impact assessment. Ecological Economics, 69(1): 82.
Wilk, J. and Hughes, D.A. 2002. Simulating the impacts of land-use and climate change on water resource
availability for a large south Indian catchment. Hydrological Sciences Journal, 47(1): 19-30.

Value of Water Research Report Series
Editorial board:
Arjen Y. Hoekstra – University of Twente, a.y.hoekstra@utwente.nl
Hubert H.G. Savenije – Delft University of Technology, h.h.g.savenije@tudelft.nl
Pieter van der Zaag – UNESCO-IHE Institute for Water Education, p.vanderzaag@unesco-ihe.org
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.

Exploring methods to assess the value of water: A case study on the Zambezi basin.
A.K. Chapagain − February 2000
Water value flows: A case study on the Zambezi basin.
A.Y. Hoekstra, H.H.G. Savenije and A.K. Chapagain − March 2000
The water value-flow concept.
I.M. Seyam and A.Y. Hoekstra − December 2000
The value of irrigation water in Nyanyadzi smallholder irrigation scheme, Zimbabwe.
G.T. Pazvakawambwa and P. van der Zaag – January 2001
The economic valuation of water: Principles and methods
J.I. Agudelo – August 2001
The economic valuation of water for agriculture: A simple method applied to the eight Zambezi basin countries
J.I. Agudelo and A.Y. Hoekstra – August 2001
The value of freshwater wetlands in the Zambezi basin
I.M. Seyam, A.Y. Hoekstra, G.S. Ngabirano and H.H.G. Savenije – August 2001
‘Demand management’ and ‘Water as an economic good’: Paradigms with pitfalls
H.H.G. Savenije and P. van der Zaag – October 2001
Why water is not an ordinary economic good
H.H.G. Savenije – October 2001
Calculation methods to assess the value of upstream water flows and storage as a function of downstream benefits
I.M. Seyam, A.Y. Hoekstra and H.H.G. Savenije – October 2001
Virtual water trade: A quantification of virtual water flows between nations in relation to international crop trade
A.Y. Hoekstra and P.Q. Hung – September 2002
Virtual water trade: Proceedings of the international expert meeting on virtual water trade
A.Y. Hoekstra (ed.) – February 2003
Virtual water flows between nations in relation to trade in livestock and livestock products
A.K. Chapagain and A.Y. Hoekstra – July 2003
The water needed to have the Dutch drink coffee
A.K. Chapagain and A.Y. Hoekstra – August 2003
The water needed to have the Dutch drink tea
A.K. Chapagain and A.Y. Hoekstra – August 2003
Water footprints of nations, Volume 1: Main Report, Volume 2: AppendicesA.K. Chapagain and A.Y. Hoekstra – November 2004
Saving water through global trade
A.K. Chapagain, A.Y. Hoekstra and H.H.G. Savenije – September 2005
The water footprint of cotton consumption
A.K. Chapagain, A.Y. Hoekstra, H.H.G. Savenije and R. Gautam – September 2005
Water as an economic good: the value of pricing and the failure of markets
P. van der Zaag and H.H.G. Savenije – July 2006
The global dimension of water governance: Nine reasons for global arrangements in order to cope with local water problems
A.Y. Hoekstra – July 2006
The water footprints of Morocco and the Netherlands
A.Y. Hoekstra and A.K. Chapagain – July 2006
Water’s vulnerable value in Africa
P. van der Zaag – July 2006
Human appropriation of natural capital: Comparing ecological footprint and water footprint analysis
A.Y. Hoekstra – July 2007
A river basin as a common-pool resource: A case study for the Jaguaribe basin in Brazil
P.R. van Oel, M.S. Krol and A.Y. Hoekstra – July 2007
Strategic importance of green water in international crop trade
M.M. Aldaya, A.Y. Hoekstra and J.A. Allan – March 2008

26. Global water governance: Conceptual design of global institutional arrangements
M.P. Verkerk, A.Y. Hoekstra and P.W. Gerbens-Leenes – March 2008
27. Business water footprint accounting: A tool to assess how production of goods and services impact on freshwater
resources worldwide
P.W. Gerbens-Leenes and A.Y. Hoekstra – March 2008
28. Water neutral: reducing and offsetting the impacts of water footprints
A.Y. Hoekstra – March 2008
29. Water footprint of bio-energy and other primary energy carriers
P.W. Gerbens-Leenes, A.Y. Hoekstra and Th.H. van der Meer – March 2008
30. Food consumption patterns and their effect on water requirement in China
J. Liu and H.H.G. Savenije – March 2008
31. Going against the flow: A critical analysis of virtual water trade in the context of India’s National River Linking
Programme
S. Verma, D.A. Kampman, P. van der Zaag and A.Y. Hoekstra – March 2008
32. The water footprint of India
D.A. Kampman, A.Y. Hoekstra and M.S. Krol – May 2008
33. The external water footprint of the Netherlands: Quantification and impact assessment
P.R. van Oel, M.M. Mekonnen and A.Y. Hoekstra – May 2008
34. The water footprint of bio-energy: Global water use for bio-ethanol, bio-diesel, heat and electricity
P.W. Gerbens-Leenes, A.Y. Hoekstra and Th.H. van der Meer – August 2008
35. Water footprint analysis for the Guadiana river basin
M.M. Aldaya and M.R. Llamas – November 2008
36. The water needed to have Italians eat pasta and pizza
M.M. Aldaya and A.Y. Hoekstra – May 2009
37. The water footprint of Indonesian provinces related to the consumption of crop products
F. Bulsink, A.Y. Hoekstra and M.J. Booij – May 2009
38. The water footprint of sweeteners and bio-ethanol from sugar cane, sugar beet and maize
P.W. Gerbens-Leenes and A.Y. Hoekstra – November 2009
39. A pilot in corporate water footprint accounting and impact assessment: The water footprint of a sugar-containing
carbonated beverage
A.E. Ercin, M.M. Aldaya and A.Y. Hoekstra – November 2009
40. The blue, green and grey water footprint of rice from both a production and consumption perspective
A.K. Chapagain and A.Y. Hoekstra – March 2010
41. Water footprint of cotton, wheat and rice production in Central Asia
M.M. Aldaya, G. Muñoz and A.Y. Hoekstra – March 2010
42. A global and high-resolution assessment of the green, blue and grey water footprint of wheat
M.M. Mekonnen and A.Y. Hoekstra – April 2010
43. Biofuel scenarios in a water perspective: The global blue and green water footprint of road transport in 2030
A.R. van Lienden, P.W. Gerbens-Leenes, A.Y. Hoekstra and Th.H. van der Meer – April 2010
44. Burning water: The water footprint of biofuel-based transport
P.W. Gerbens-Leenes and A.Y. Hoekstra – June 2010
45. Mitigating the water footprint of export cut flowers from the Lake Naivasha Basin, Kenya
M.M. Mekonnen and A.Y. Hoekstra – June 2010
46. The green and blue water footprint of paper products: methodological considerations and quantification
P.R. van Oel and A.Y. Hoekstra – July 2010

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