Local decadal prediction according to statistical/dynamical approaches.

Dynamical climate models present an initialization problem due to the poor availability of deep oceanic data, which is required for the model assimilation process. In this sense, teleconnection indices, defined from spatial and temporal patterns of climatic variables, are conceived as useful tools to complement them. In this work, the near-term climate predictability of 35 temperature and 36 precipitation time series of three cities (Barcelona, Bristol and Lisbon) was analysed using two approaches: (a) a statistical-dynamical combination of self-predictable teleconnection indices and long-term climate projections on a local scale and (b) dynamical model outputs obtained from drift-corrected decadal experiments. Fourier and wavelet analyses were used to assess the predictability of seven teleconnection indices thanks to a cross-validation process (with differentiated training and validation periods). The standardized absolute error of teleconnection-based prediction was compared with that obtained from a (9) multi-model ensemble based on the Coupled Model Intercomparison Project Phase 5. Results showed that decadal predictions at horizons between 20 and 30 years are adequate for temperature and precipitation if a teleconnection-based approach is used, while temperature is better predicted from a 5-year horizon using drift-corrected dynamical outputs.

Impact of climate change on drought in Aragon (NE Spain).

Droughts are one of the extreme climatic phenomena with the greatest and most persistent impact on health, economic activities and ecosystems and are poorly understood due to their complexity. The exacerbation of global warming throughout this century probably will cause an increase in droughts, so accurate studies of future projections at a local level, not done so far, are essential. Climate change scenarios of drought indexes for the region of Aragon (Spain) based on nine Earth System Models (ESMs) and two Representative Concentration Pathways (RCPs) corresponding to the fifth phase of the Coupled Model Intercomparison Project (CMIP5) have been generated for the first time. Meteorological Drought episodes were analysed from three main aspects: magnitude (index values), duration and spatial extent. The evolution of drought is also represented in a novel way, allowing identification, simultaneously, of the intensity of the episodes as well as their duration in different periods of accumulation and, for the first time, at the observatory level. Future meteorological drought scenarios based on the Standardized Precipitation Index (SPI) hardly show variations in water balance with respect to normal values. However, the Standardized Precipitation Evapotranspiration Index (SPEI) which, in addition to precipitation, considers evapotranspiration, shows a clear trend towards increasingly intense periods of drought, especially when considering cumulative periods and those at the end of the century. Representation of the territory of the drought indexes reflects that the most populated areas (Ebro Valley and SW of the region), will suffer the longest and most intense drought episodes. These results are key in the development of specific measures for adapting to climate change.

Incorporating exposure to pitch canker disease to support management decisions of Pinus pinaster Ait. in the face of climate change.

Climate change is gravely affecting forest ecosystems, resulting in large distribution shifts as well as in increasing infection diseases and biological invasions. Accordingly, forest management requires an evaluation of exposure to climate change that should integrate both its abiotic and biotic components. Here we address the implications of climate change in an emerging disease by analysing both the host species (Pinus pinaster, Maritime pine) and the pathogen's (Fusarium circinatum, pitch canker) environmental suitability i.e. estimating the host's risk of habitat loss and the disease`s future environmental range. We constrained our study area to the Spanish Iberian Peninsula, where accurate climate and pitch canker occurrence databases were available. While P. pinaster is widely distributed across the study area, the disease has only been detected in its north-central and north-western edges. We fitted species distribution models for the current distribution of the conifer and the disease. Then, these models were projected into nine Global Climate Models and two different climatic scenarios which totalled to 18 different future climate predictions representative of 2050. Based on the level of agreement among them, we created future suitability maps for the pine and for the disease independently, which were then used to assess exposure of current populations of P. pinaster to abiotic and biotic effects of climate change. Almost the entire distribution of P. pinaster in the Spanish Iberian Peninsula will be subjected to abiotic exposure likely to be driven by the predicted increase in drought events in the future. Furthermore, we detected a reduction in exposure to pitch canker that will be concentrated along the north-western edge of the study area. Setting up breeding programs is recommended in highly exposed and productive populations, while silvicultural methods and monitoring should be applied in those less productive, but still exposed, populations.

Climate change scenarios for temperature and precipitation in Aragón (Spain).

By applying a two-step statistical downscaling technique to four climate models under different future emission scenarios, we produced future projections of the daily precipitation and the maximum and minimum temperatures over the Spanish region of Aragón. The reliability of the downscaling technique was assessed by a verification process involving the comparison of the downscaled reanalysis data with the observed data--the results were very good for the temperature and acceptable for the precipitation. To determine the ability of the climate models to simulate the real climate, their simulations of the past (the 20C3M output) were downscaled and then compared with the observed climate. The results are quite robust for temperature and less conclusive for the precipitation. The downscaled future projections exhibit a significant increase during the entire 21st century of the maximum and minimum temperatures for all the considered IPCC future emission scenarios (A2, A1B, B1), both for mid-century (increases relative to the 1971-2000 averages between 1.5°C and 2.5°C, depending on the scenario) and for the end of the century (for the maximum temperature of approximately 3.75°C, 3.3°C, and 2.1°C for A2, A1B, and B1 scenarios respectively, and for the minimum temperature of 3.1°C, 2.75°C, and 1.75°C). The precipitation does not follow such a clear tendency (and exhibits greater uncertainties), but all the scenarios suggest a moderate decrease in rainfall for the mid-century (2-4%) and for the end of the century (4.5-5.5%). Due to the clear spatial differences in climate characteristics, we divided the studied area into five sub-regions to analyse the different changes on these areas; we determined that the high mountains (Pyrenees, Mediterranean-Oceanic transitional climate) and the lands of the Ebro River Basin (Continental sub-Mediterranean climate) will probably be the most affected.