HELIX-RD2

With the target of limiting global warming to 2°C increasingly difficult to achieve, policymakers, businesses and other decision-makers need to plan to adapt to changes in climate under higher levels of global warming. This requires coherent information on the future climate conditions, and the consequences of different adaptation actions. International negotiations on limiting global warming also require clear information on the consequences of different levels of climate change. While a vast array of projections, scenarios and estimates of future climate change and its impacts already exists, much is conflicting, unclear, of unknown levels of certainty and difficult to use to inform decisions. HELIX addresses this by providing a clear, coherent, internally-consistent view of a manageable number of "future worlds" under higher levels of global warming reached under a range of circumstances, supported by advice on which aspects are more certain and which less certain. This will be delivered through groundbreaking scientific research across a range of physical, natural and social science disciplines, in close engagement with experienced users of climate change information in order to ensure appropriate focus, clarity and utility. Since international climate policy often frames climate change in terms of levels of global warming relative to pre-industrial state, our research will focus on addressing the questions "What do 4°C and 6°C worlds look like compared to 2°C?" and "What are the consequences of different adaptation choices?" Our core product will a set of eight coherent global scenarios of the natural and human world at these levels of warming achieved at different rates and with different pathways of adaptation by society. A second product will provide more detailed information in three focus regions; Europe, East Africa and the north-eastern Indian sub-continent. This will all be supported by a comprehensive analysis of confidence and uncertainty.

PIK lead WP4 on biophysical impacts, synthesis of impacts of climate change at different levels of global warming, development of impact emulators providing a simplified description of the relationship allowing for highly efficient impact projections for arbitrary global temperature pathways. PIK are also participants in WP5, global socio-economic impacts, providing a crosssectoral integration of "cascading" climate impacts within the global economic supply network, and in the analysis of tipping points.