Decisions made when updating national climate projections for Norway

<p>The Norwegian Centre for Climate Services (NCCS), a national collaboration on the natural scientific knowledge for climate adaptation, has published the national climate assessment reports for Norway (Hanssen-Bauer et al., 2009; Hanssen-Bauer et al., 2015, Hanssen-Bauer et al., 2019). The work on national climate projections and associated products are described in Nilsen et al., 2022. In the wake of IPCC AR6 (CMIP6), the Norwegian Environment Agency has commissioned an update of the report &#8220;Climate in Norway 2100&#8221;, including new fine-scale climate projections for Norway. The report will present changes in past climate of the last 2000 years, current climate and hydrological normals and projected future changes in climate, hydrology and effects on natural hazards.</p><p>A literature review of climate change in the Arctic islands of Svalbard will be included (mainly based on &#8220;Climate in Svalbard 2100&#8221; (Hanssen-Bauer et al., 2019)). However, Svalbard will not be included in the modeling work due to the large difference in data availability, both measurements and model simulations, between mainland Norway and the Arctic.</p><p>Due to limited resources, delays in the international collaboration on climate projections (CMIP and EURO-CORDEX) and expectations from society of updated recommendations in the light of the already launched IPCC report, strict priorities in the modeling group are necessary. Early model selection and ensemble size is particularly urged by hydrological modeling. In this presentation we will share decisions made so far in the project. We anticipate our priorities and considerations as working with the newest generation of climate model simulations to be of interest to the international community and other national climate services.&#160;</p><p>The presentation will include considerations around emission scenarios and the GCM-RCM ensemble, where a combination of CMIP5 and CMIP6 simulations will be used. We also present results from the historical climate development, the use of empirical statistical downscaling, convective-permitting simulations for improved understanding of changes in heavy rainfall, bias adjustment methods, improvements in the hydrological model and some early ideas on data distribution and outreach.&#160;</p><p>References:&#160;</p><p>Hanssen-Bauer et al., 2009: Klima i Norge 2100. Bakgrunnsmateriale til NOU Klimatilpasning (in Norwegian).</p><p>Hanssen-Bauer et al., 2015: Klima i Norge 2100. Kunnskapsgrunnlaget for klimatilpasning oppdatert i 2015 (in Norwegian). NCCS report 02/2015.</p><p>Hanssen-Bauer et al., 2019: Climate in Svalbard. A knowledge base for climate adaptation. NCCS report 02/2019.</p><p>Nilsen et al., 2022: From climate model output to actionable climate information in Norway. Frontiers in Climate, accepted.</p>