Integration of the Climate Impact Assessments with Future Projections

Climate projections are essential in order to extend the case-study impacts and vulnerability assessments to encompass future climate change. Thus climate-model based indicators for the future (to 2050 and for the A1B emissions scenario) are presented for the climate and atmosphere theme (including indices of temperature and precipitation extreme events), together with biogeophysical and socioeconomic indicators encompassing the other case-study themes. For the latter, the specific examples presented here include peri-urban fires, air pollution, human health risks, energy demand, alien marine species and tourism (attractiveness and socio-economic consequences). The primary source of information about future climate is the set of global and regional model simulations performed as part of CIRCE. These have the main novel characteristic of incorporating a realistic representation of the Mediterranean Sea including coupling between sea and atmosphere. These projections are inevitably subject to uncertainties relating to unpredictability, model structural uncertainty and value uncertainty. These uncertainties are addressed by taking a multi-model approach, but problems remain, for example, due to a systematic cold bias in the CIRCE models. In the context of the case-study integrated assessments, there are also uncertainties ‘downstream’ of climate modeling and the construction of climate change projections – largely relating to the modeling of impacts. In addition, there are uncertainties associated with all socio-economic projections used in the case studies – such as population projections. Thus there are uncertainties inherent to all stages of the integrated assessments and it is important to consider all these aspects in the context of adaptation decision making.