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The objective of this study is to investigate the long-term effects of climate change on olive crops in Andalusia, one of the most important olive growing areas worldwide, using tailored climate indices and return period analysis. Both the climatic indices and the occurrence probabilities of bad years in terms of olive yield and olive fly risk are being calculated for the reference period 1971–2000 and for the near (2031–2060) and distant future (2071–2100) under two emission scenarios using an ensemble of five high-resolution, bias-adjusted Regional Climate Models. Three threshold-based temperature related indices (SPR32, SU36, SU40) as well as mean temperature and precipitation related climatic indices (SPRTX, WINRR) have been calculated, revealing increasing changes in the near and distant future and pointing out the challenges faced by the olive sector due to climate change; a robust increase of the threshold-based indices are found in central and northern Andalusia, mainly in the provinces of Seville, Cordoba and Jaen. Although the changes of the precipitation-related index are less pronounced for the near future, robust decreases are projected for the distant future period under a high emission scenario. The identification of the bad years is based on observational data from five monitoring stations in Andalusia (Malaga, Granada, Sevilla, Cordoba and Jaen). The role of certain meteorological parameters (precipitation, temperature, relative humidity) is investigated and the return levels of interest for the calculation of the occurrence probabilities are estimated by the upper tail of the reference distribution. The results indicate an overall tendency for increased occurrence probability of bad years in terms of olive yield due to future decreased precipitation; bad year occurrences with return periods of below 2 years may increase by about 20 % by 2060. Spatial variability is also evident with overall larger changes in western Andalusia. The range of the olive fly is expected to decrease in the northern areas of Andalusia.

To evaluate the role of biomass burning emissions, and in particular of residential wood heating, as a result of the economic recession in Greece, carbon monoxide (CO) atmospheric concentrations from five (5) stations of the National Air Pollution Monitoring Network in Athens, spanning the period 2000-2015, in conjunction with black carbon (BC) concentrations from the NOA (National Observatory of Athens) station at Thissio were analysed. The contribution of the different sources to the diurnal cycle of these two pollutants is clear, resulting to a morning peak, mainly due to traffic, and a late evening peak attributed both to fossil fuel (traffic plus central heating) and biomass combustion. Calculated morning and evening integrals of CO peaks, for the investigated period, show consistent seasonal modulations, characterised by low summer and high winter values. The summer and winter morning CO peak integrals demonstrate an almost constant decreasing trend of CO concentrations over time (by almost 50% since 2000), attributed to the renewal of passenger car fleet and to reduced anthropogenic activities during the last years. On the other hand, an increase of 23%-78% (depending on the monitoring site) in the winter evening integrals since 2012, provides evidence of the significant contribution of biomass combustion, which has prevailed over fossil fuel for domestic heating. CO emitted by wood burning was found to contribute almost 50% to the total CO emissions during night time (16:00-5:00), suggesting that emissions from biomass combustion have gained an increasing role in atmospheric pollution levels in Athens., (Copyright © 2017 Elsevier B.V. All rights reserved.)