2014, Stagl, J., Mayr, E., Koch, H., Hattermann, F.F., Huang, S.

For the management of protected areas knowledge about the water regime plays a very important role, in particular in areas with lakes, wetlands, marches or floodplains. The local hydrological conditions depend widely on temporal and spatial variations of the main components of the hydrologic cycle and physiographic conditions on site. To preserve a favourable conservation status under changing climatic conditions park managers require information about potential impacts of climate change in their area. The following chapter provides an overview of how climate change affects the hydrological regimes in Central and Eastern Europe. The hydrological impacts for the protected areas are area-specific and vary from region to region. Generally, an increase in temperature enhances the moisture holding capacity of the atmosphere and thus, leads to an intensification of the hydrological cycle. Key changes in the hydrological system include alterations in the seasonal distribution, magnitude and duration of precipitation and evapotranspiration. This may lead to changes in the water storage, surface runoff, soil moisture and seasonal snow packs as well as to modifications in the mass balance of Central European glaciers. Partly, water resources management can help to counterbalance effects of climate change on stream flow and water availability.

2014, O'Neill, B.C., Kriegler, E., Riahi, K., Ebi, K.L., Hallegatte, S., Carter, T.R., Mathur, R., van Vuuren, D.P.

The new scenario framework for climate change research envisions combining pathways of future radiative forcing and their associated climate changes with alternative pathways of socioeconomic development in order to carry out research on climate change impacts, adaptation, and mitigation. Here we propose a conceptual framework for how to define and develop a set of Shared Socioeconomic Pathways (SSPs) for use within the scenario framework. We define SSPs as reference pathways describing plausible alternative trends in the evolution of society and ecosystems over a century timescale, in the absence of climate change or climate policies. We introduce the concept of a space of challenges to adaptation and to mitigation that should be spanned by the SSPs, and discuss how particular trends in social, economic, and environmental development could be combined to produce such outcomes. A comparison to the narratives from the scenarios developed in the Special Report on Emissions Scenarios (SRES) illustrates how a starting point for developing SSPs can be defined. We suggest initial development of a set of basic SSPs that could then be extended to meet more specific purposes, and envision a process of application of basic and extended SSPs that would be iterative and potentially lead to modification of the original SSPs themselves.

2019, Levermann, A., Feldmann, J.

Recent observations and ice-dynamic modeling suggest that a marine ice-sheet instability (MISI) might have been triggered in West Antarctica. The corresponding outlet glaciers, Pine Island Glacier (PIG) and Thwaites Glacier (TG), showed significant retreat during at least the last 2 decades. While other regions in Antarctica have the topographic predisposition for the same kind of instability, it is so far unclear how fast these instabilities would unfold if they were initiated. Here we employ the concept of similitude to estimate the characteristic timescales of several potentially MISI-prone outlet glaciers around the Antarctic coast. Our results suggest that TG and PIG have the fastest response time of all investigated outlets, with TG responding about 1.25 to 2 times as fast as PIG, while other outlets around Antarctica would be up to 10 times slower if destabilized. These results have to be viewed in light of the strong assumptions made in their derivation. These include the absence of ice-shelf buttressing, the one-dimensionality of the approach and the uncertainty of the available data. We argue however that the current topographic situation and the physical conditions of the MISI-prone outlet glaciers carry the information of their respective timescale and that this information can be partially extracted through a similitude analysis.

2016, Trusilova, K., Schubert, S., Wouters, H., Früh, B., Grossman-Clarke, S., Demuzere, M., Becker, P.

2014, Anders, I., Stagl, J., Auer, I., Pavlik, D.

Climate change is affecting many fields of the society, policy, economy and environment. Information on changes in the climate during the last centuries and especially in near and far future is essential. Estimation and quantification of changes in climate variables and indices are a necessary precondition for adaptation and mitigation measures. This chapter gives an overview on measures, observations as well as dynamical models, which are available to estimate changes in the past and the present climate as well as for a possible future climate. It summarises the state of knowledge according to the climate change signal in Central and Eastern Europe. Moreover it identifies the limitations and uncertainties of the measures and the derived information.

2019, Schlemm, T., Levermann, A.

Over large coastal regions in Greenland and Antarctica the ice sheet calves directly into the ocean. In contrast to ice-shelf calving, an increase in calving from grounded glaciers contributes directly to sea-level rise. Ice cliffs with a glacier freeboard larger than ≈100 m are currently not observed, but it has been shown that such ice cliffs are increasingly unstable with increasing ice thickness. This cliff calving can constitute a self-amplifying ice loss mechanism that may significantly alter sea-level projections both of Greenland and Antarctica. Here we seek to derive a minimalist stress-based parametrization for cliff calving from grounded glaciers whose freeboards exceed the 100 m stability limit derived in previous studies. This will be an extension of existing calving laws for tidewater glaciers to higher ice cliffs.

To this end we compute the stress field for a glacier with a simplified two-dimensional geometry from the two-dimensional Stokes equation. First we assume a constant yield stress to derive the failure region at the glacier front from the stress field within the glacier. Secondly, we assume a constant response time of ice failure due to exceedance of the yield stress. With this strongly constraining but very simple set of assumptions we propose a cliff-calving law where the calving rate follows a power-law dependence on the freeboard of the ice with exponents between 2 and 3, depending on the relative water depth at the calving front. The critical freeboard below which the ice front is stable decreases with increasing relative water depth of the calving front. For a dry water front it is, for example, 75 m. The purpose of this study is not to provide a comprehensive calving law but to derive a particularly simple equation with a transparent and minimalist set of assumptions.

2017, Piniewski, M., Mezghani, A., Szczésniak, M., Kundzewicz, Z.W.

This study presents the analysis of bias-corrected projections of changes in temperature and precipitation in the Vistula and Odra basins, covering approximately 90% of the Polish territory and small parts of neighbouring countries in Central and Eastern Europe. The ensemble of climate projections consists of nine regional climate model simulations from the EURO-CORDEX ensemble for two future periods 2021-2050 and 2071-2100, assuming two representative concentration pathways (RCPs) 4.5 and 8.5. The robustness is measured by the ensemble models' agreement on significant changes.We found a robust increase in the annual mean of daily minimum and maximum temperature, by 1-1.4 °C in the near future and by 1.9-3.8 °C in the far future (areal-means of the ensemble mean values). Higher increases are consistently associated with minimum temperature and the gradient of change goes from SWto NE regions. Seasonal projections of both temperature variables reflect lower robustness and suggest a higher future increase in winter temperatures than in other seasons, notably in the far future under RCP 8.5 (by more than 1 °C). However, changes in annual means of precipitation are uncertain and not robust in any of the analysed cases, even though the climate models agree well on the increase. This increase is intensified with rising global temperatures and varies from 5.5% in the near future under RCP 4.5 to 15.2%in the far future under RCP 8.5. Spatial variability is substantial, although quite variable between individual climate model simulations. Although seasonal means of precipitation are projected to considerably increase in all four combinations of RCPs and projection horizons for winter and spring, the high model spread reduces considerably the robustness, especially for the far future. In contrast, the ensemble members agree well that overall, the summer and autumn (with exception of the far future under RCP 8.5) precipitation will not undergo statistically significant changes.

2014, Vohland, K., Rannow, S., Stagl, J.

Model results can serve as a basis for adaptation in conservation management. They can help understanding the impact of climate change, and support the formulation of management measures. However, model results rely strongly on the quality and the resolution of the input data; they contain significant uncertainties and need to be interpreted in the context of the modelling assumptions. The perception of models and their results differs between disciplines as well as between science and practice. Part of this gap derives from the long ‘model cascade’ used for the assessment of climate related impacts on biodiversity. For this ‘model cascade’ model results from Global Climate Models are often used to drive Regional Downscaled Climate Models and are transferred to hydrological models or distribution models of plants and animals. In fact, most assessments of potential impacts of climate change on biodiversity rely on habitat modelling of plants and animals. But, only few decision makers are trained to analyse the different outcomes of climate impact modelling. If modelling is integrated into conservation management it must be based on an evaluation of the need for information in protected areas and an assessment of model use in the management process, so as to guarantee maximum usability.

2014, Boysen, L.R., Brovkin, V., Arora, V.K., Cadule, P., De Noblet-Ducoudré, N., Kato, E., Pongratz, J., Gayler, V.

Biogeophysical (BGP) and biogeochemical (BGC) effects of land-use and land cover change (LULCC) are separated at the global and regional scales in new interactive CO2simulations for the 21st century. Results from four earth system models (ESMs) are analyzed for the future RCP8.5 scenario from simulations with and without land-use and land cover change (LULCC), contributing to the Land-Use and Climate, IDentification of robust impacts (LUCID) project. Over the period 2006-2100, LULCC causes the atmospheric CO2concentration to increase by 12, 22, and 66 ppm in CanESM2, MIROC-ESM, and MPI-ESM-LR, respectively. Statistically significant changes in global near-surface temperature are found in three models with a BGC-induced global mean annual warming between 0.07 and 0.23 K. BGP-induced responses are simulated by three models in areas of intense LULCC of varying sign and magnitude (between g 0.47 and 0.10 K). Modifications of the land carbon pool by LULCC are disentangled in accordance with processes that can lead to increases and decreases in this carbon pool. Global land carbon losses due to LULCC are simulated by all models: 218, 57, 35 and 34 Gt C by MPI-ESM-LR, MIROC-ESM, IPSL-CM5A-LR and CanESM2, respectively. On the contrary, the CO2-fertilization effect caused by elevated atmospheric CO2concentrations due to LULCC leads to a land carbon gain of 39 Gt C in MPI-ESM-LR and is almost negligible in the other models. A substantial part of the spread in models' responses to LULCC is attributed to the differences in implementation of LULCC (e.g., whether pastures or crops are simulated explicitly) and the simulation of specific processes. Simple idealized experiments with clear protocols for implementing LULCC in ESMs are needed to increase the understanding of model responses and the statistical significance of results, especially when analyzing the regional-scale impacts of LULCC.

2015, Koch, H., Vögele, S., Hattermann, F.F., Huang, S.