Early emissions peak more relevant than emissions reduction rate: study
Sea and land. Coastal flooding is one of the climate change impacts examined in the new study. Photo: Thinkstock
“There is considerable variability in the impacts avoided between the sectors”, the international team of authors points out, led by Nigel Arnell of the University of Reading and including two scientists affiliated with the Potsdam Institute for Climate Impact Research. “An emissions pathway peaking in 2016 and declining at 5 percent per year, for example, avoids between 58 and 66 percent of the adverse impacts of climate change on coastal flood risk, when assuming no upgrades in coastal protection measures – but only 30‐40 percent of the adverse impacts on crop suitability,” says Jochen Hinkel, guest scientist at PIK and senior researcher at the Global Climate Forum.
The authors put a strong focus on the remaining uncertainties. “The proportion of impacts avoided at the global scale is relatively robust for most indicators across different climate model patterns, but the absolute magnitude of avoided impacts varies considerably,” the study says. Also, only one impact computer simulation – a so-called model – is used in each sector. Furthermore, the indirect consequences of changes in one sector for another are not calculated.
The Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), a community-driven effort coordinated by PIK, aims at advancing this strand of research. Based on common background scenarios (climate and socio-economic), a quantitative estimate of impacts and uncertainties for different sectors and from multiple impact models will be derived. Fast-track outcomes will be presented and discussed at the first Impacts World Conference in Potsdam this May and get published in special issues of the Proceedings of the National Academy of Sciences and of Earth System Dynamics.
Article: Arnell, N.W., Lowe, J.A., Brown, S., Gosling, S.N., Gottschalk, P., Hinkel, J., Lloyd-Hughes, B., Nicholls, R.J., Osborn, T.J., Osborne, T.M., Rose, G.A., Smith, P., Warren, R.F. (2013): A global assessment of the effects of climate policy on the impacts of climate change. Nature Climate Change (online)
Weblink to the article: http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1793.html
Weblink to more information on the study: http://www.reading.ac.uk/news-and-events/releases/PR482917.aspx
Weblink to ISI-MIP and Impacts World Conference 2013: http://www.pik-potsdam.de/research/climate-impacts-and-vulnerabilities/research/rd2-cross-cutting-activities/isi-mip