Evaluating skills and issues of quantile-based bias adjustment for climate change scenarios

Daily meteorological data such as temperature or precipitation from climate models are needed for many climate impact studies, e.g., in hydrology or agriculture, but direct model output can contain large systematic errors. A large variety of methods exist to adjust the bias of climate model outputs. Here we review existing statistical bias-adjustment methods and their shortcomings, and compare quantile mapping (QM), scaled distribution mapping (SDM), quantile delta mapping (QDM) and an empiric version of PresRAT (PresRATe). We then test these methods using real and artificially created daily temperature and precipitation data for Austria. We compare the performance in terms of the following demands: (1) the model data should match the climatological means of the observational data in the historical period; (2) the long-term climatological trends of means (climate change signal), either defined as difference or as ratio, should not be altered during bias adjustment; and (3) even models with too few wet days (precipitation above 0.1 mm) should be corrected accurately, so that the wet day frequency is conserved. QDM and PresRATe combined fulfill all three demands. For (2) for precipitation, PresRATe already includes an additional correction that assures that the climate change signal is conserved.</p

Zusammenfassung für Entscheidungstragende

Die Zusammenfassung für Entscheidungstragende fasst die Inhalte des APCC Special Report „Landnutzung und Klimawandel in Österreich“ in komprimierter Form zusammen. Im Lichte des Zusammenhanges von Landnutzung, Klimawandel und gesellschaftlichem Wohlergehen werden die gegenwärtige Situation und zukünftige Entwicklungen in Österreich synoptisch beschrieben, wesentliche Optionen der Klimawandelanpassung und des Klimaschutzes dargestellt, deren Trade-offs und Synergien systematisch beleuchtet und zentrale Einsichten zur Umsetzung von Strategien zum Klimaschutz und der Klimawandelanpassung in Österreich zusammengefasst

Technische Zusammenfassung

Die Technische Zusammenfassung des APCC-Sonderberichts ″Landnutzung und Klimawandel in Österreich″ umfasst die Kernbotschaften der Kapitel 1–9. In ihr sind die Hauptaussagen zu den sozioökonomischen und klimatischen Treibern der Landnutzungsänderungen, zu den Auswirkungen von Landnutzung und -bewirtschaftung auf den Klimawandel, zu Minderungs- und Anpassungsoptionen im Kontext nachhaltiger Entwicklungsziele sowie zu Synergien, Zielkonflikten und Umsetzungsbarrieren von Klimamaßnahmen enthalten

Anthropogenic intensification of short-duration rainfall extremes

Short- duration (1-3 h) rainfall extremes can cause serious damage to societies through rapidly developing (flash) flooding and are determined by complex, multifaceted processes that are altering as Earth's climate warms. In this Review, we examine evidence from observational, theoretical and modelling studies for the intensification of these rainfall extremes, the drivers and the impact on flash flooding. Both short- duration and long- duration (\textgreater1 day) rainfall extremes are intensifying with warming at a rate consistent with the increase in atmospheric moisture (~7% K-1), while in some regions, increases in short- duration extreme rainfall intensities are stronger than expected from moisture increases alone. These stronger local increases are related to feedbacks in convective clouds, but their exact role is uncertain because of the very small scales involved. Future extreme rainfall intensification is also modulated by changes to temperature stratification and large- scale atmospheric circulation. The latter remains a major source of uncertainty. Intensification of short- duration extremes has likely increased the incidence of flash flooding at local scales and this can further compound with an increase in storm spatial footprint to considerably increase total event rainfall. These findings call for urgent climate change adaptation measures to manage increasing flood risks

Evidence of trans-generational developmental modifications induced by simulated heat waves in an arthropod

Heat waves are considered to pose a greater risk to arthropods with their limited thermoregulation abilities than the increase of mean temperatures. theoretically, within-and trans-generational modifications may allow populations to keep pace with rapidly occurring heat waves. Here, we evaluated this assumption using individuals of predatory mite Amblydromalus limonicus from the F1 and F2 generation, which were exposed to summer or simulated heat wave conditions during juvenile development. independent of generation, survival and male body size were insensitive to heat waves. Heat stress elongated juvenile development of F1 males and females, and lowered the F1 female size at maturity indicating non-adaptive within-generational effects. Trans-generational modifications speeded up the development of F2 males and females and resulted in larger body size of F2 females deriving from the heat wave-experienced F1 generation. Faster F2 development should be adaptive, because it reduces the exposure time to heat waves and promotes an early beginning of mating activities. Being large at extreme high temperatures maybe a benefit for the F2 females, because large individuals are less vulnerable to dehydration and overheating. Thus, the potential fitness loss from reduced F1 growth should be compensated by increased fitness in the F2 indicating adaptive trans-generational modifications. Climate warming has wide-ranging impact on organisms limited in their internal thermo-regulation such as arthropods, because temperature nearly affects all vital processes such as survival, development and reproduction 1. Arthropods may respond to changing thermal conditions via behavioural thermoregulation reflected in range shifts, genetic adaptation, and phenotypic plasticity 2. Behavioural responses by large-range avoidance and the selection of thermally suitable locations resulting in poleward and upward range shifts are well documented in some taxa 3 , but should be reserved for arthropods with well-developed dispersal abilities such as some butterflies, dragonflies and grasshoppers 4. The opportunities of the majority of arthropods, however, are limited to genetic modifications and/or phenotypic plasticity 5,6 , whereas the former mechanism might be appropriate to adopt to long-term environmental changes such as the annual increase of the mean temperatures 7. Heat waves, however, are fundamentally different from mild warming in the ecological consequences for arthropods and their evolutionary responses 8-10. First, heat waves can exceed the critical thermal maxima of arthropods within few hours. Accordingly, even when the daily mean temperatures are still within a suitable thermal range, a single aberration beyond their critical thermal maxima can be fatal 11. Consequently, these rapid thermal changes are considered to have stronger effects on survival, development and reproduction of arthropods than small shifts in mean temperatures 12,13. Second, the time frame for effective genetic adaptations, however, is significantly shorter for populations exposed to rapidly occurring heat waves than to the slow increase of the mean temperatures, which should make plastic modifications more likely 8,9. Temperature is one of the most prominent agents of developmental plasticity 14 , which may result in adaptive modifications to cope with heat waves. Such adaptations usually occur within a generation (i.e