COACCH produced a “more accurate and downscaled economic valuation of climate-induced impacts and risks in Europe” (Call impact 1) assessing with high spatial resolution consequences for/from agriculture, forestry, fishery, sea-level rise, river flooding, transportation, energy demand, energy supply, labour productivity, ecosystems, health. Impacts were also compounded into unifying macro-economic assessments.
COACCH indicated that climate change impacts may entail for the EU a median GDP loss of 2.2% by 2070 (Fig.1). These results are higher compared to previous estimates. COACCH results also highlighted important regional differences, with one quarter of EU regions estimated to experience a loss that is larger than 5% of gross regional product. The main drivers of GDP losses were from sea-level rise (although they drop dramatically under the adaptation scenario), river floods and crop yield changes (Fig.2). There were also important impacts from labour productivity, energy supply and energy demand, more pronounced in southern Europe (Fig.2). While ambitious mitigation policy had major benefits, these arise mostly after mid-century. This also means that the impacts in the next two decades can only be reduced with adaptation.
COACCH developed a throughout analysis on climate and social economic tipping points. It examined 3 of the former and 9 of the latter, co-selected with stakeholders for their relevance for the EU economic system. The major conclusion is that local, but highly socially and economically damaging “tipping points” can emerge in many EU areas by mid-century. An example is the case of potential collapses in flood insurance markets because of rising premiums due to climate change. High increases in unaffordability were projected in Eastern European countries, as well as regions in Sweden, Portugal and Italy (Fig.3).
The COACCH project devoted a particular attention to “Decrease uncertainties on the economic value of climate action in the EU, over the longer term (2050 and beyond) call impact 2). This has been done a) defining, with stakeholders a multi climate change and social economic scenario space to capture scenario uncertainty, b) specifying for each impact type ranges capturing climate and impact model uncertainty and finally c) specifying different assumptions on economic adjustments.
Uncertainty analysis showed a clear dominance of model uncertainty (related to the choice of climate models, or to the assumptions on the functioning of the economic systems) over scenario uncertainty. Within scenario uncertainty, that stemming from the climate futures dominates that from the economic futures (Fig.4).
New damage functions (Fig.5) for major geo-political macro regions (also available at the NUTS2 resolution for the EU) were then estimated and implemented in three Integrated Assessment Models. A full cost-benefit policy analysis showed that with medium damages, the optimal temperature is in line with the 2°C target from the Paris Agreement. When assuming the high end of the damage function, optimal temperatures were in line with a 1.5°C goal. These outcomes are obtained without including catastrophic events.
COACCH also fostered greater transparency of models, methods and tools (Call impact 3) by co-designing research and co-delivering its outcomes with the reference stakeholders guaranteeing easier interpretation and use of recommendations. It also developed an open-access interactive web tool (www.scenarioxplorer.coacch.eu/) enabling easy and intuitive exploration of COACCH results and methods, granted on-line open access to all data produced by the project (
https://iiasa.github.io/COACCH/en/master/index.html#coacch-data-repository(s’ouvre dans une nouvelle fenêtre)) so that information can be evaluated, reused and progressed by other research groups, produced easy reading syntheses specifically tailored to non-academic users.
COACCH supported EU policy action and international scientific assessments (Call Impact 4). The COACCH outcomes were used to support the background papers for the new RTD Mission area on Adaptation, the Glasgow City Region Adaptation Strategy, the UK Climate Change Risk Assessment, the Catalonia Climate Change Office, the macroeconomic assessment of climate change impacts of the Italian Ministry of Infrastructures and Sustainable Mobility. On the more scientific ground, COACCH promoted: direct data and information exchange with the SOCLIMPACT and the CASCADES H2020 research projects, supported the DG CLIMA funded SAM-PS study on adaptation modelling. Its findings were included in the UNEP Adaptation Gap Report and the Global Centre on Adaptation Report on the State of Adaptation in Africa. COACCH project is acknowledged in the CLIMATEADAPT portal.
