The Water Footprint: An appropriate tool for environmental communication in the forest

sector ?

M. Futter Stockholm Water Conference

August 25, 2011 martyn.futter@slu.se

Acknowledgements

• METLA, the Finnish Forest Research Institute

• Nordic Forestry Centre of Advanced Research – Ecosystem Services

• Kevin Bishop, Stefan Löfgren, Hjalmar Laudon

• Andis Bardulis, Nicholas Clarke, David Ellison, Leena Finer, Lars Högbom, Ari Lauren, Samuli Launianinen, Eva Ring

Sweden – a forest country

http://www.physorg.com/news188731079.html

Forests cover 2/3 of Sweden. The forest industry is an important part of the Swedish economy, providing ~90 000 jobs and > SEK 120 billion each year in export earnings. Sweden is the world’s 2nd largest exporter of sawn timber and the 4th largest exporter of pulp and paper; forest bioenergy is increasingly important. 65% of the Swedish forest is certified under FSC or PEFC or both.

”Footprints” and Environmental Certification

More and more metrics are being developed to measure environmental performance. Most forest products in Sweden are now environmentally certified, many organizations have achieved ISO 14001 certification and carbon footprint accounting is becoming commonplace. Increasingly, consumers are basing their purchasing decisions on the real or perceived environmental impact of goods and services.

Water Footprint (WF) The WF of a product is an empirical indicator of how much water is consumed … over the whole supply chain of the product. It is a multidimensional indicator, showing volumes but also making explicit the type of water use (evaporation of rainwater, surface water or groundwater, or pollution of water) and the location and timing of water use. The WF shows human appropriation of the world’s limited freshwater resources and thus provides a basis for assessing the impacts of goods and services on freshwater systems and formulating strategies to reduce those impacts.

www.waterfootprint.org

Components of a Water Footprint

Blue water footprint: consumption of surface and groundwater along the supply chain of a product. ‘Consumption’ refers to loss of water from the available ground-surface water body in a catchment area. These occur when water evaporates, returns to another catchment area or the sea or is incorporated into a product. Green water footprint: consumption of rainwater insofar as it does not become run-off (i.e. interception and evapotranspiration). Grey water footprint: the volume of freshwater that is required to assimilate the load of pollutants given natural background concentrations and existing ambient water quality standards.

Problems with the Water Footprint

• Global indexes are not appropriate for communicating about water

• Growing forests are not always human ”appropriation” of water

• WF needs to be interpreted in light of local water scarcity or other measures of water availability

• WF green water calculations must include precipitation recycling

• WF of managed forests should be referenced to that of natural vegetation

Carbon ≠ Water

A footprint measures the total resource appropriation (i.e. greenhouse gas emissions, water use, etc.) caused directly and indirectly by a person, organization, event or product.1

One tonne of CO2 has approximately the same effect on the atmospheric energy balance regardless of where it is emitted.

The consequences of using one tonne of H2O are inextricably linked to where and when it is used.

Increased water efficiency in Sweden will not obviously help water shortages in sub-Saharan Africa.

A reduced carbon footprint in Fennoscandia will have global benefits.

1adapted from Carbon Footprint, www.carbonfootprint.com

Water Footprint of Wood Production ?

Van Oel and Hoekstra 2010

Country Pine Broadleaf Eucaluptus

Bo

real

Tem

per

ate

Tem

per

ate

Sub

tro

pic

al

Tro

pic

al

Sweden 413 381 463 Finland 592 488 451 China 891 1001 693 1105 995 Brazil 214 233 Max 891 1001 797 1105 1081 Min 373 298 262 214 233

WF m3 / m3 wood produced

What is the human appropriation of water in wood production?

1 m3solid pine wood, freshly harvested contains ~400 kg H20, or 0.4 m3 / m3 wood produced. Photosynthesis: 6 CO2 + 6 H2O -> C6 H12O6 + 6 O2

6 CO2 : 264 g C6 H12O6 : 180 g 6 H2O : 108 g 6 O2 : 192 g 1 m3 dry pine contains ~400 kg C6 H12O6 ; 400 * (108/180) = 240 kg H20, or or 0.24 m3 / m3 wood produced

Forests and Water – a question of scale

Malin Falkenmark and colleagues have developed a conceptual model of water, primarily for assessing sustainability of food production. Blue water has dominated the water perceptions in the past but represents 1/3 of the real freshwater resource. Green water or the moisture in the soil, flows back to the atmosphere as a vapor flow, dominated by consumptive water use by the vegetation. Falkenmark (2009)

Forests and Water – scale issues

Demand Side (small scale) Trees and forests are consumers of available water; competitors for other downstream water uses (agriculture, energy, industry, households). Removing trees will increase blue (surface water ) flows. Afforestation will increase water consumption and reduce blue water flows.

Supply Side (large scale) Forest cover has a positive effect on water supply at regional and global scales through the intensification of the water cycle. Green (evapotranspiration) water can be returned as recycled precipitation (P). P recycling raises the likelihood of local P events and favors cross-continental transport of moisture vapor and thus increased P in locations more distant from the ocean-based hydrologic cycle.

Upstream Green Water Consumption Evapotranspiration (ET)

Downstream Blue Water Consumption

Cropland Green and Blue Water ConsumptionRainfed + Irrigated

Pre

cip

itat

ion

100%

65%

35%

The WF treats all evapotranspiration (ET) as a loss; it does not account for precipitation derived from ET. By one estimate, ~1/2 the ET from Sweden is recycled as precipitation elsewhere.

Green water calculations must include precipitation recycling

From van der Ent et al. 2010

Is there any evidence of increased evapotranspiration (ET) in Sweden ?

0

500

1000

1500

2000

2500

3000

3500

1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Milj

. m

³sk

Year

Döda träd Dead or windthrown trees

Lövträd Broad-leaved

Gran Norway spruce

Tall Scots pine

Virkesförrådets utveckling sedan 1920-talet. Alla ägoslag 1

Trend for total standing volume since 1920, all land-use 1bThe volume of standing timber in Sweden has increased substantially since the 1920’s. Has there been any consequent change in ET? If there has been a chage in ET, there should be a change in runoff (R) P = ET + R

Has the increase in standing timber volume had any impact on runoff in large Swedish catchments?

From Lindström and Bergström, 2004

If more intensive forest production in Sweden is consuming more water, all other things being equal, runoff should decrease; there is no evidence of such a decrease in long term Swedish runoff records. The hypothesis of increased human appropriation of forest waters for increased forest production in the 20th century cannot be supported with long term runoff data. In Sweden, green water footprints of managed forests may not differ from ”reference” conditions-

WF needs to be interpreted in light of water scarcity or other measures of water availability

http://maps.grida.no/go/graphic/water-poverty-index-by-country-in-2002 Water stress(withdrawal-to-availability)

< 0.3

0.3 - 0.4

0.4 - 0.5

0.5 - 0.6

0.6 - 0.7

0.7 - 0.8

0.8 - 0.9

0.9 - 1.0

> 1.0

Water Poverty Index (WPI, right) measures water resources, access, capacity, use and environmental impact. A high WPI is better. Water sustainability (below) can be measured as the ratio of water withdrawn to availability.

By several measures, Sweden and other parts of Fennoscandia have much more water than other parts of the world.

Problems with the Water Footprint

• Global indexes are not appropriate for communicating about water

• WF needs to be interpreted in light of local water scarcity or other measures of water availability

• WF green water calculations must include precipitation recycling

• Growing forests are not always human ”appropriation” of water

• WF of managed forests should be referenced to that of natural vegetation

Conclusions and Next Steps

• The Water Footprint, as it currently exists, is not an appropriate tool for environmental communication in the Fennoscandic forest sector

• Focusing too much on inappropriate green water indicators may deflect attention from areas in which water efficiency could be improved

• We, the scientific community and forestry sector, have to develop appropriate tools for environmental communication