Relevant, reliable and robust local-scale climate projections for Norway

R3 represents an innovative endeavor to provide climate services on local to regional scales in Norway. Norway is characterized by large regional differences in geography and climate. Obtaining credible projections of climate change on local scales has been, and remains, extremely challenging. R3 took an integrated approach that encompasses a range of outcomes involving changes in precipitation, temperature and flooding. In addition, R3 addressed the so-called "usability gap" between climate change research and decision-making. The need for robust and credible estimates of local-scale climate change in decision-relevant contexts was, and still is, pressing both within Norway and abroad. R3 has implemented innovative modeling techniques to provide robust high-resolution climate projections for Norway. The hybrid approach consists of a coupling of state-of-the-art approaches and results in an ensemble of climate projections to address and estimate uncertainty for future climate. The knowledge gained was further used in hydrology modeling systems for impact assessment. The developed framework is important for producing reliable climate change projections on local to regional scales provided by the Norwegian Climate Service Centre in the future. During the project we had interactive dialogues with a multitude of stakeholders, for example during climate seminars with young people and politicians, and outreach events during Arendalsuka. R3?s largest events were the Klimathons in January 2018 and March 2019. In 2019 about 80 persons in interdisciplinary and intersectoral groups collaborated intensively over two days, discussing and designing practical and strategic solutions to the challenges of climate adaptation at the local level. The Klimathons provided a concrete arena for meeting and understanding each other?s daily realities through collaboration and dialogue across research environments and levels of public administration and will be continued after the project period.

R3 has generated important experience with knowledge application, co-production of knowledge, and issues that scientists and practitioners encounter in climate change adaptation. Two klimathons have expanded dialogue between academic and stakeholder communities through interdisciplinary and intersectoral networks. Moreover, R3 has advanced the use of a hybrid downscaling approach which enables local-scale information through high resolution and provides uncertainty estimates through ensembles of climate projections for Norway. All achievable within todays limited computational resources because the method combines dynamical and statistical downscaling. The use of weather generators has improved the projection of catchment-scale hydrological simulations. These methodological innovations and scientific advances are highly relevant for future climate projections for Norway and the Norwegian Centre for Climate Services, and are transferable to other regions of the world.

R3 represents a new and innovative approach to provide climate services at local scales in Norway. It will accomplish this through implementation of an integrated approach that aims to account for a range of possible outcomes and extensive interaction with stakeholders. Norway is characterized by large regional differences in geography and climate. An integrated modelling approach - one that can encompass a range of outcomes and represents detailed spatial structure and dynamics - is required to produce reliable climate change projections. Our approach addresses these requirements and also addresses the "usability gap" between climate information and decision-making. The need for improved, robust and credible estimates of local-scale climate change in decision-relevant contexts is pressing. We identify four challenges that currently hinder production of relevant, reliable and robust climate projections on local scales: a) Insufficient resolution in existing multi-model ensembles; b) Persistent biases in driving general circulation models; c) Dynamical approaches sample a small range of outcomes and under-represent uncertainty; and d) Lack of effective two-way communication between scientists and user communities often results in outputs/products do not match users' need for decision-relevant climate information. R3 will make use of existing capabilities of the Norwegian Centre for Climate Services (NCCS) to develop a new framework for producing reliable climate change projections on local scales. We address the challenges described above through a number of actions, which culminate in an integrated modelling strategy for local scale climate projections. The added value of this approach will be evaluated, both from the stakeholders' perspective and in terms of scientific outcomes. The project's methodological innovations and scientific advances will benefit Norway and will provide a framework that will be generally transferable to other regions of the world.