PRESENTATION

This method, named IMPACT World+, is the update of the IMPACT 2002+, LUCAS, and EDIP methods. With IMPACT World+ we propose a midpoint-damage framework with three distinct complementary viewpoints: 1) midpoint impacts, 2) damages on human health, ecosystem quality, and resources & ecosystem services, and 3) water and carbon footprints, as area of concerns. Most of the regional impact categories have been spatially resolved and all the long-term impact categories have been temporally resolved: short-term damages (over the 100 years after the emission) have been differentiated from long-term damages. The IMPACT World+ method integrates developments in the following categories, all structured according to fate (or competition/scarcity), exposure, effect, and severity: a) Complementary to GWP100, the IPCC Global Temperature Potentials (GTP100) are used as a proxy for global warming longer-term impacts at midpoint. At damage level, short-term damages (over the first 100 years after emission) are also differentiated from longer-term damages. b) Marine acidification impact is based on the same fate model as global warming, combined with the H+concentration affecting 50% of the exposed species. c) For mineral resources depletion impact, the material competition scarcity index is applied as a midpoint indicator. d) Terrestrial and freshwater acidification impact assessment combines, at are solution of 2°x 2.5° (latitude x longitude), global atmospheric source-deposition relationships with soil and water ecosystems sensitivity. e) Freshwater eutrophication impact is spatially assessed at a resolution grid of 0.5°x0.5°, based on a global hydrological dataset. f) Ecotoxicity and human toxicity impact is based on the parameterized version of USEtox for continents. We consider indoor emissions and differentiate impacts of metal sand persistent organic pollutants for the first 100 years from longer-term impacts. g) Particulate matter formation related impacts on human health are modelled using the USEtox regional archetypes to calculate intake fractions and epidemiologically derived effect factors. h) Water consumption impacts are modelled using the consensus scarcity indicator AWARE as a proxy midpoint, whereas damages account for competition and adaptation capacity. i) Impacts on ecosystem quality from land transformation and occupation are empirically characterized at the biome level.

IMPACT World+ provides consistent characterization factors for all regionalized impacts at four complementary resolutions: global default, continental default, country default, and native (i.e. original and non-aggregated) resolutions. IMPACT World+ enables the practitioner to parsimoniously account for spatial variability and to identify the elementary flows to be regionalized in priority to increase the discriminating power of LCA.