Land use impacts in LCA: a framework from the UNEP/SETAC Life Cycle Initiative*

Transcription

1 Land use impacts in LCA: a framework from the UNEP/SETAC Life Cycle Initiative* Expert Workshop for the Definition of Indicators for Biodiversity and Soil Quality for Life Cycle Assessment (LCA) University of Surrey, th June 2006 Llorenç Milà i Canals, CES, University of Surrey C Bauer, J Depestele, A Dubreuil, R Freiermuth Knuchel, G Gaillard, O Michelsen, R Müller-Wenk, B Rydgren *Based on Milà i Canals L, Bauer C, Depestele J, Dubreuil A, Freiermuth R, Gaillard G, Michelsen O, Müller-Wenk R, Rydgren B. (2006) Key elements in a framework for land use impact assessment in LCA. The International Journal of Life Cycle Assessment Accepted. DOI: /lca

2 Contents Context What is the UNEP/SETAC LC Initiative? Why LCA? Relevance of land use impacts Main impact pathways from land use Biodiversity (intrinsic value) Biotic production potential Ecological soil quality Environmental mechanism Transformation/Occupation: process; intervention; impact Considerations for the application of the framework Reference situation Future impacts and Time frame Bio-geographical differentiation for land use impacts Impact indicators Conclusions and Implementation: situation vs. spatial differentiation

3 The UNEP/SETAC Life Cycle Initiative Mission: to develop and disseminate practical tools for evaluating the opportunities, risks, and trade-offs associated with products and services over their entire life cycle to achieve sustainable development Life Cycle Impact Assessment (LCIA) Programme: to establish and provide guidance on models and characterisation factors for the different impact categories TF2 on resources and land use: Context

4 Context Why Life Cycle Assessment (LCA)? LCA is a systems analysis tool providing information on: Environmental effects of a product/service Over its life cycle, from cradle (acquisition of raw materials) to grave (waste management) Goal and scope definition State study objectives; set system boundaries; decide methodological issues; etc. Inventory Analysis Collect data on inputs and outputs crossing the system boundaries; allocate burdens; model emissions; etc. Impact Assessment Translate inventory results into a meaningful and relevant set of environmental issues affected by the system; etc Interpretation Use the results from the impact assessment and inventory phases to answer the questions set in the goal and scope definition; check that the conclusions are consistent with the assumptions made; etc Enabling organisations to manage their extended environmental impacts within a structured and comprehensive framework: Environmental hotspots? (focusing improvement opportunities) Compare alternative technologies Increase efficiency

5 Relevance of land use impacts Production of raw materials often takes place in ecologically fragile areas: agriculture; forestry; mining Land use by humans exerts considerable damages on land functions the decline of Europe's biodiversity in many regions [...] derives mainly from highly intensive, partially industrial forms of agricultural and silvicultural land use, from an increased fragmentation of remaining natural habitats by infrastructure and urbanisation [ ] (The Dobris Assessment, 1995) soil degradation has been often driven by increasing demand for food production (UNEP s GEO-3, 2002) greenhouse gas emissions caused by land cover changes are of the same order of magnitude as those derived from combustion (IPCC 2001) Context and yet they are not commonly included in LCA!

6 Impact pathways from land use processes LCI Interventions [area; area time] Midpoints [land quality time] Damages to Main impact pathways Land Occupation and Transformation Biodiversity (intrinsic value) Change/maintenance of overall species composition; loss of species Ecological soil quality soil s Life Support Functions not directly used by humans (filter + buffer capacity; C cycle; etc.) Biotic production potential Change in soil s fertility (main Life Support Function directly used by humans) + use value of biodiversity Damage to the Natural Environment Damage to the Natural Resources

7 Transformation: process; intervention; impact Environmental mechanism Transformation process: change of properties in a land area to fit a new type of human use Transf. intervention: when listed in LCI [m 2 ] Transf. impact: amount of [land quality time] not available due to a transformation intervention (shaded) Reference (no transformation) Natural relaxation (land is abandoned after transformation)

8 Occupation: process; intervention; impact Environmental mechanism Occupation process: maintenance of properties in a land area to keep a human use (no intended transf.) Occup. intervention: when listed in LCI [m 2 time] Occup. impact: amount of [land quality time] not available due to an occupation intervention (shaded) Reference (land is abandoned instead of used) Natural relaxation (land is abandoned after occupation)

9 LCI modelling parameters Environmental mechanism Quantitative description of land use process: change in land quality (different parameters for each impact) Time Area

10 Dynamic Reference Situation Default: natural relaxation Consequential LCA: most likely alternative land use Application of the framework

11 Time Frame for impacts after land use intervention Application of the framework Default: model impacts until or new steady state Huge uncertainties on future events! 2 alternative approaches: pulse vs. continued occupation: Pulse Continued

12 Time Frame for impacts after land use intervention Non reversed impacts must be red-flagged! (interpretation) OR consider a large virtual relaxation time (e.g. 10,000 years) Application of the framework

13 Bio-geographical differentiation for land use impacts Application of the framework Land use impacts require bio-geographical differentiation: The same land use intervention has different consequences depending on the sensitivity and inherent land quality of the environment where it occurs Options to contextualise impacts: thresholds; distance to climax ; dose-response functions? A consistent approach needs to be derived with other impact categories (eutrophication; acidification; toxicity) 100% 0% constant slope -ph 100% 0% Dependent on impact pathway! Critical load -ph 100% 0% Critical load -ph

14 Indicators for land use impacts (i.e. how do we assess land quality?) Application of the framework Different indicators for each impact pathway Differences at midpoint / damage level Possibly opposite signs! ( what is good for bioproductivity may be bad for biodiversity ) Still under development (examples in the preworkshop document) Work for these two days!

15 Worked example Case A SOC as indicator of soil quality A1) Intensive arable crop, temperate grassland A2) Organic arable crop, temperate grassland Application of the framework A3) Intensive arable crop, from cleared moist forest Q 1 [t C/ha], 30 top cm Q 2 [t C/ha], 30 top cm Q rel [t C/ha], 30 top cm Relaxation rate [t C/ha/year] A4) Intensive arable crop, moist forest (cleared long ago) Land occupation per functional unit [m 2 year/fu] Carbon deficit of system [t C year ha - 1 ] Carbon deficit per FU [t C year FU -1 ] System A A A A SOC evolution from OM addition, tillage Steady state from maps, literature, etc. Relaxation from literature, maps, expert judgement, etc. Occupation from technical info (productivity) Negative values imply a credit for the system

16 A need and a (possible) way forward Conclusions and Implementation Land use impacts on (at least) biodiversity, biotic production potential and ecological soil quality need to be included in LCA, particularly in: (bio)energy; food; forestry; mining; waste treatment; etc. Bio-geographical differentiation needs to be included in land use impact assessment or the results will be meaningless How? Situation differentiation: definition of land use archetypes with relevant information for user of LCA results (e.g. purchaser of landbased products) Spatial differentiation: provision of relevant parameters with the LCI information for a detailed assessment of the effects of land management practices (e.g. for land manager)

17 THANK YOU! Any questions? Land use impacts in LCA: a framework from the UNEP/SETAC Life Cycle Initiative