However, in this report, only values shaded in green have been included in Trucost’s water valuation model. The valuation of water is based on the opportunity cost of water or the value generated by water when it is not abstracted. Consumptive uses (for agriculture or industry) of water have therefore been excluded. Option and non-use values have also been excluded given the difficulty inherent in their valuation. Values for direct non-consumptive uses (including hydro-electric power, recreation, navigation and cultural activities) and indirect uses (including ecosystem services such as flood control, regulation of water flows and supplies, carbon sequestration, nutrient retention and climate regulation) were identified in academic literature in different geographical locations.180,181 A function of water value (in $ per m3) relative to water scarcity (% of internal renewable water resources abstracted) was developed based on the values estimated in the academic literature.179,180,181 This function was then used to estimate the opportunity cost of water in any geographic location where water scarcity is known, by adjusting the function for purchasing power parity at that location.
LAND AND WATER POLLUTANTS STEP 1: QUANTIFICATION OF IMPACTS Life cycle analysis characterization models, such as Recipe, calculate the human, terrestrial, freshwater and marine toxicity of thousands of substances when released in different media. Trucost used a global adaption of Recipe by EUSES-LCA to model land and water pollutants. Human toxicity impacts are expressed in Disability Adjusted Life Years (DALYs) and terrestrial, freshwater and marine toxicity are expressed in Ecosystem Damage Potential (EDP).182,183,184,185,186 While it is hard to state an order of magnitude, toxicity data are among the most uncertain in lifecycle analysis characterization models. Trucost based its analysis on the best available data, but recognizes this weakness in the underlying data. STEP 2: VALUATION OF ENVIRONMENTAL TOXICITY The NEEDS Project approach developed a formula to estimate the monetary cost per kilogram of toxic substances deposited in natural ecosystems.187 Within the NEEDS project, a regression analysis between willingness-to-pay and several variables were performed. The EDP valuation is known to have a positive correlation with population – as more people live close to an area with high biodiversity there will be more people that value biodiversity. The EPD value is known to have a negative correlation with the ecosystem size – if an ecosystem covers a larger area, the value per unit area will be less. Similarly, as biodiversity change increases, the value per unit of biodiversity diminishes. Using these variables, the formula below calculates the value of EDP in different regions.
The value of ecosystem damage is a function of the change in biodiversity due to the emission of the toxic substance and the willingness to pay for biodiversity (adjusted for purchasing power parity). STEP 3: VALUATION OF human TOXICITY In order to put a value on the years of life lost, Trucost used the NEEDS project approach. The results of this approach are based on a contingent valuation questionnaire applied in nine European countries: France, Spain, UK, Denmark, Germany, Switzerland, Czech Republic, Hungary and Poland. The value was adapted to other countries based on country-specific income levels. To avoid ethical criticisms on the value of life and disease incidence in different countries, Trucost applied the global median value to value DALYs in different countries.
MANAGED PLASTIC As explained in appendix 3, plastic can be collected and treated through different routes. Treatment routes considered here are landfill, incineration with and without energy recovery and recycling. One should note that even if impacts are generated by the treatment of waste, treatment is a necessity and its impact is small compared to those of littered plastic. In order to apply natural capital valuations on these treatment routes, Trucost calculated the quantity of greenhouse gas and other air, land and water pollutants emitted, and water used in these processes as per Appendix 3 and Tables 9 and 10, and applied the relevant valuations as described above.
LITTERED PLASTIC When littered in an unregulated manner, Trucost assumed two possible pathways depending on the sector under consideration, namely reaching or not reaching marine environments. The following table summarises the pathway of each product. It is understood that a significant amount will be transported over time by the winds, streams, waterways, and eventually partially end up in the ocean. While there are estimates of the total volume of plastic from land reaching the ocean per year, there
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