Engineering sustainability the need for eco efficiency and eco effectiveness

Transcription

1 Engineering sustainability the need for eco efficiency and eco effectiveness Michael Hauschild Technical University of Denmark 1

2 Outline Sustainability challenge Eco efficiency and Life cycle assessment Eco efficiency and eco effectiveness 2

3 The sustainability challenge I P A T Pop GDP person I GDP I is the environmental impact (Graedel and Allenby, 1995) Pop is the global population GDP is the Affluence, the material standard of living person I is the Technology factor environmental impact per GDP created value 3

4 The sustainability challenge I Pop GDP person I GDP The global population may level off around 10 billion Material standard of living will grow strongly in newly industrialised countries (Asia, South America) The environmental impact already exceeds sustainable levels in many areas So what is the challenge? 4

5 Factor 4, 10 or 20 I GDP The technology factor,, I Pop GDP person I GDP the impact caused by our creation of wealth and economic value must decrease 4 20 times in order to counterbalance the expected growth in population and material standard of living achieve the needed reduction in the environmental impact i.e. be environmentally sustainable 5

6 Eco efficiency Eco efficiency reflects the environmental price of obtaining a service, meeting a need, creating a value Eco-efficiency = Delivered service Environmental impact = 1/T Eco efficiency is the reciprocal of the technology factor in the IPAT equation Improved eco efficiency means creating more with less Life cycle assessment (LCA) is the tool to assess eco efficiency 6

7 The life cycle of a product 7

8 Life cycle assessment Inventory of elementary flows Product life cycle Emission Emission CAS.no. to air to w ater Substance g g 2-hydroxy-ethanacrylate ,0348 4,4-methylenebis cyclohexylamine ,9E-02 Ammonia ,7E-05 4,2E-05 Arsenic ( As ) ,0E-06 Benzene (cur 5,0E-02 Lead ( Pb ) ,5E-06 Butoxyethanol ,6E-01 Carbondioxide ,6E+02 Carbonmonoxide ( CO ) ,9E-01 Cadmium (Cd) ,2E-07 Chlorine ( Cl2 ) ,6E-04 Chromium ( Cr VI ) ,3E-06 Dicyclohexane methane ,1E-02 Nitrous oxide( N2O ) ,7E-02 2,4-Dinitrotoluene ,5E-02 HMDI ,5E-02 Hydro carbons (electricity, stationary combustio - 1,7E+00 Hydrogen ions (H+) - 1,0E-03 i-butanol ,5E-02 i-propanol ,2E-01 copper ( Cu ) ,8E-05 Mercury( Hg ) ,7E-06 Methane ,0E-03 Methyl i-butyl ketone ,7E-02 Monoethyl amine ,9E-06 Nickel ( Ni ) ,1E-05 Nitrogen oxide ( NOx ) ,1E+00 NMVOC, diesel engine (exhaust) - 3,9E-02 NMVOC, pow er plants (stationary combustion) - 3,9E-03 Ozone ( O3 ) ,8E-03 PAH ikke specifik 2,4E-08 Phenol ,3E-05 Phosgene ,4E-01 Polyeter polyol ikke specifik 1,6E-01 1,2-propylenoxide ,2E-02 Nitric acid (c 8,5E-02 Hydrochloric acid (c 1,9E-02 Selenium ( Se ) ,6E-05 Sulphur dioxide( SO2 ) ,3E+00 Toluene ,8E-02 Toluene-2,4-diamine ,9E-02 Toluene diisocyanat ( TDI ) ,6E-01 Total-N - 2,6E-05 Triethylamine ,6E-01 Unspecified aldehydes - 7,5E-04 Uspecified organic compounds - 1,5E-03 Vanadium ,8E-04 VOC, diesel engine (exhaust) - 6,4E-05 VOC, stationary combustion (coal fired) - 4,0E-05 VOC, stationary combustion (natural gas fired) - 2,2E-03 VOC, stationary combustion (oil fired) - 1,4E-04 Xylene ,4E-01 Zinc ( Zn ) ,9E-05 Category indicator results for product Global warming kg CO 2 -eq Ozone depletion 0 kg CFC11-eq Acidification 868 kg SO 2 -eq Photochemical ozone formation 200 kg C 2 H 4 -eq Nutrient enrichment kg NO - 3 -eq Human toxicity 3, m 3 air Ecotoxicity 2, m 3 water Land use 170 ha yr 8

9 Relative and absolute sustainability Eco efficiency supports relative sustainability ( more sustainable than )? Same or higher functionality with less environmental impact Lower impact Absolute sustainability ( sustain able )? Where is the boundary beyond which the activity becomes unsustainable? What is sustainable in absolute terms? Sustainable Unsustainable Higher impact 9

10 Efficiency and effectiveness Doing the things right or doing the right things? (eco)efficiency: reaching the goal causing minimal environmental impact but is it the right goal? what about rebound effects where increased efficiency may lead to increased consumption? where are the boundaries for sustainability? 10

11 A sustainable level of impact Sustainability: Fulfilment of needs Today and in the future Which needs? How to fulfil them? For how many? Carrying capacity: The maximum impact that an ecosystem can sustain without experiencing permanent changes in its structure or central functionalities No effect For all categories of environmental impact 11

12 Absolute sustainability boundaries Safe operating space 1950 now Pre industrial level Rockström et al.,

13 Impact category Sustainability person equivalents Sustainable impact (person.year) Carrying capacity approach (indicator based on) Climate change 0.98 ton CO 2 eq Resilience (2 target) Climate change, alternative 0.52 ton CO 2 eq Resilience (350 ppm CO 2 ) Ozone depletion 7.8*10 2 Resilience (7.5% decrease in average ozone kg CFC 11 eq conc.) Protection of sensitive species Photochemical ozone formation 47 kg NMVOC eq (3 ppm h AOT40) Terrestrial acidification 1.4*10 3 mole H+ eq Buffer flow (1080 mole H + eq/ha/year) Terrestrial eutrophication 1.8*10 3 mole N eq Buffer flow (1270 mole N eq/ha/year) Freshwater eutrophication 0.46 kg P eq Resilience (0.3 mg/l P) Marine eutrophication 31 kg N eq Resilience (1.75 mg/l N) Freshwater ecotoxicity 1.0*10 3 [PAF]*m 3 *day Protection of sensitive species (HC5(NOEC)) Land use, soil quality 1.2 tons eroded soil Buffer flow (0.85 tons/(ha*year)) Land use, biodiversity loss 9.5*10 3 m 2 *year Resilience (31% un conserved land are) Water depletion 490 m 3 Buffer flow (2100 km 3 /year) Bjørn & Hauschild,

14 Case study: LCA of 4 windows Function: allow daylight into a building equivalent to light being transmitted through an area of 1.23x1.48 m 2 with visible light transmittance of at least 0.7 for 20 years Owsianiak et al. (2014) 14

15 Results normalised against current levels of impact 1,4 Current impact Person Equivalents 1,2 1 Person years 0,8 0,6 0,4 0,2 0 Wood Wood/aluminum PVC Wood/composite 15

16 Results normalised against sustainable levels of impact 1,4 Sustainable impact Person Equivalents 1,2 1 Person years 0,8 0,6 0,4 0,2 0 Wood Wood/aluminum PVC Wood/composite 16

17 Interpretation of sustainability normalised scores Consumer perspective: How large a part of my space is occupied by this product or activity? Is it worth that much to me if my consumption must stay within the sustainability boundaries? 17

18 Engineering sustainability We need to combine eco efficiency and eco effectiveness Target solutions that are sustainable also in absolute terms All technologies and products have a life cycle analyse it to avoid problem shifting, and include all relevant environmental impacts Benchmark the solutions on their eco efficiency Relate improvement to absolute boundaries, considering rebound effects Do the right things right Employ the highest eco efficiency towards achieving a sustainable solution Remember that sustainability also has a social and an economic dimension 18

19 Sustainability calls for many skills Sciences: Define sustainability and create the basis for making it operational Engineering: Make sustainability operational by creating sustainable technologies Business: Develop sustainability management, business models, communication addressing all three dimensions of sustainability Together: Educate and train professionals that will support sustainable transitions at all levels in society 19