Suchergebnisse

Cover -- Titel -- Über den Autor -- Zum Buch -- Impressum -- Inhalt -- Einleitung -- 1 Die Vielfalt der weltweiten Wasservorkommen -- 1.1 Niederschlag über Land – vitale Quelle für Mensch und Natur -- 1.2 Schicksal von Regentropfen -- 1.3 Planetare Grenze für die Wassernutzung -- 1.4 Blaues Wasser, grünes Wasser -- 2 Menschliche Wassernutzungen -- 2.1 Eine kurze Weltgeschichte der Wassernutzung -- 2.2 Wassernutzung und -verbrauch 1900 – 2100: Immer weiter, immer mehr? -- 2.3 Bewässerte und unbewässerte Land- und Viehwirtschaft heute -- 2.4 Wasserfußabdruck von Agrarprodukten und virtueller Wasserhandel -- 3 Wasserknappheit und Welternährung heute -- 3.1 Bestimmung von «Wasserknappheit» und ihr derzeitiges Ausmaß -- 3.2 Wassermangel und Nahrungsmittelproduktion -- 4 Globaler Klimawandel und Wasserressourcen -- 4.1 Klimawandel: Grundsätzliches und jüngste Trends -- 4.2 Dürren und Landwirtschaft -- 5 Blick in die Zukunft: Genug Wasser zur Nahrungsmittelproduktion? -- 5.1 Warum zwei Grad? -- 5.2 Wasserverknappung unter Klimawandel und Bevölkerungswachstum -- 6 Wege zur Wassereinsparung in der Landwirtschaft -- 6.1 Zurück aus der Zukunft -- 6.2 Hin zum «weichen Pfad»: Paradigmenwandel in der Wasserwirtschaft -- 6.3 Innovative Nutzung blauen und grünen Wassers: ein weites Spektrum -- 6.4 Weniger Wasser essen -- 7 Bausteine für ein neues Wasserethos: Religiöse und ethische Aspekte -- 8 Resümee und Perspektiven -- 8.1 Stereo-Perspektiven -- 8.2 Globale Wasserkrise? -- 8.3 Visionen -- Quellen und Anmerkungen

The growth of biomass is considered the most efficient method currently available to extract carbon dioxide from the atmosphere. However, biomass carbon is easily degraded by microorganisms releasing it in the form of greenhouse gases back to the atmosphere. If biomass is pyrolyzed, the organic carbon is converted into solid (biochar), liquid (bio-oil), and gaseous (permanent pyrogas) carbonaceous products. During the last decade, biochar has been discussed as a promising option to improve soil fertility and sequester carbon, although the carbon efficiency of the thermal conversion of biomass into biochar is in the range of 30%–50% only. So far, the liquid and gaseous pyrolysis products were mainly considered for combustion, though they can equally be processed into recalcitrant forms suitable for carbon sequestration. In this review, we show that pyrolytic carbon capture and storage (PyCCS) can aspire for carbon sequestration efficiencies of >70%, which is shown to be an important threshold to allow PyCCS to become a relevant negative emission technology. Prolonged residence times of pyrogenic carbon can be generated (a) within the terrestrial biosphere including the agricultural use of biochar; (b) within advanced bio-based materials as long as they are not oxidized (biochar, bio-oil); and (c) within suitable geological deposits (bio-oil and CO 2 from permanent pyrogas oxidation). While pathway (c) would need major carbon taxes or similar governmental incentives to become a realistic option, pathways (a) and (b) create added economic value and could at least partly be implemented without other financial incentives. Pyrolysis technology is already well established, biochar sequestration and bio-oil sequestration in soils, respectively biomaterials, do not present ecological hazards, and global scale-up appears feasible within a time frame of 10–30 years. Thus, PyCCS could evolve into a decisive tool for global carbon governance, serving climate change mitigation and the sustainable development goals ...

Das Konzept der Planetaren Grenzen wurde 2009 durch eine internationale Forschergruppe um Johan Rockström formuliert und 2015 durch Will Steffen und weitere Wissenschaftlerinnen und Wissenschaftler überarbeitet und aktualisiert (Rockström et al. 2009; Steffen et al. 2015b). Das Konzept entstand vor dem Hintergrund des Zeitalters des Anthropozäns, das verbunden ist mit einem schnell wachsenden Druck auf die Umwelt und immer stärkerer Degradation und Verknappung von globalen Umweltgütern und einer möglichen Gefährdung der Funktionen des Erdsystems. Die Belastung der globalen Umwelt und Ökosysteme durch den Menschen hat ein Ausmaß erreicht, bei dem plötzliche nicht-lineare systemische Veränderungen nicht mehr auszuschließen sind. Das UFOPLAN-Vorhaben 'Planetare Grenzen – Anforderungen an die Wissenschaft, Zivilgesellschaft und Politik' (FKZ 3714 100 0) setzt an der Herausforderung der Operationalisierung des Konzeptes der Planetaren Grenzen an. Ziel war es, die Anforderungen, die das Konzept an Politik, Wissenschaft, Zivilgesellschaft und Wirtschaft stellt, zu analysieren und entsprechend konkrete Informationen für die politische Umsetzung des Konzepts bereitzustellen. Dafür wurden Querschnittspapiere erstellt, die sich mit Themen beschäftigen, die für diverse politische Prozesse von Bedeutung sind - wie bspw. das kommunikative Potenzial des Konzepts, Risiken bei Grenzüberschreitung und der Methodologie zur Operationisierung. Außerdem wurden Papiere zu politischen Fokusthemen erarbeitet, die sich mit der Frage auseinandersetzen, in welcher Weise das Konzept der Planetaren Grenzen an einzelnen Stellen der Umweltpolitik sinnvoll eingesetzt werden kann, bspw. bei der Erarbeitung einer nationalen Stickstoffstrategie sowie des Integrierten Umweltprogramms 2030. Wichtige nächste Schritte für die Operationalisierung des Konzeptes stellen u.a. eine stärkere Aufnahme der Planetaren Grenzen in Nachhaltigkeitsstrategien sowie die Ausrichtung der Wissenschaftsförderung auf die integrierte Weiterentwicklung des Konzeptes dar.

International audience ; Large-scale hydrological models describing the terrestrial water balance at continental and global scales are increasingly being used in earth system modeling and climate impact assessments. However, because of incomplete process understanding and limits of the forcing data, model simulations remain uncertain. To quantify this uncertainty a multimodel ensemble of nine large-scale hydrological models was compared to observed runoff from 426 small catchments in Europe. The ensemble was built within the framework of the European Union Water and Global Change (WATCH) project. The models were driven with the same atmospheric forcing data. Models were evaluated with respect to their ability to capture the interannual variability of spatially aggregated annual time series of five runoff percentiles--derived from daily time series--including annual low and high flows. Overall, the models capture the interannual variability of low, mean, and high flows well. However, errors in the mean and standard deviation, as well as differences in performance between the models, became increasingly pronounced for low runoff percentiles, reflecting the uncertainty associated with the representation of hydrological processes, such as the depletion of soil moisture stores. The large spread in model performance implies that any single model should be applied with caution as there is a great risk of biased conclusions. However, this large spread is contrasted by the good overall performance of the ensemble mean. It is concluded that the ensemble mean is a pragmatic and reliable estimator of spatially aggregated time series of annual low, mean, and high flows across Europe.

International audience ; Large-scale hydrological models describing the terrestrial water balance at continental and global scales are increasingly being used in earth system modeling and climate impact assessments. However, because of incomplete process understanding and limits of the forcing data, model simulations remain uncertain. To quantify this uncertainty a multimodel ensemble of nine large-scale hydrological models was compared to observed runoff from 426 small catchments in Europe. The ensemble was built within the framework of the European Union Water and Global Change (WATCH) project. The models were driven with the same atmospheric forcing data. Models were evaluated with respect to their ability to capture the interannual variability of spatially aggregated annual time series of five runoff percentiles--derived from daily time series--including annual low and high flows. Overall, the models capture the interannual variability of low, mean, and high flows well. However, errors in the mean and standard deviation, as well as differences in performance between the models, became increasingly pronounced for low runoff percentiles, reflecting the uncertainty associated with the representation of hydrological processes, such as the depletion of soil moisture stores. The large spread in model performance implies that any single model should be applied with caution as there is a great risk of biased conclusions. However, this large spread is contrasted by the good overall performance of the ensemble mean. It is concluded that the ensemble mean is a pragmatic and reliable estimator of spatially aggregated time series of annual low, mean, and high flows across Europe.

International audience ; Large-scale hydrological models describing the terrestrial water balance at continental and global scales are increasingly being used in earth system modeling and climate impact assessments. However, because of incomplete process understanding and limits of the forcing data, model simulations remain uncertain. To quantify this uncertainty a multimodel ensemble of nine large-scale hydrological models was compared to observed runoff from 426 small catchments in Europe. The ensemble was built within the framework of the European Union Water and Global Change (WATCH) project. The models were driven with the same atmospheric forcing data. Models were evaluated with respect to their ability to capture the interannual variability of spatially aggregated annual time series of five runoff percentiles--derived from daily time series--including annual low and high flows. Overall, the models capture the interannual variability of low, mean, and high flows well. However, errors in the mean and standard deviation, as well as differences in performance between the models, became increasingly pronounced for low runoff percentiles, reflecting the uncertainty associated with the representation of hydrological processes, such as the depletion of soil moisture stores. The large spread in model performance implies that any single model should be applied with caution as there is a great risk of biased conclusions. However, this large spread is contrasted by the good overall performance of the ensemble mean. It is concluded that the ensemble mean is a pragmatic and reliable estimator of spatially aggregated time series of annual low, mean, and high flows across Europe.

International audience ; Large-scale hydrological models describing the terrestrial water balance at continental and global scales are increasingly being used in earth system modeling and climate impact assessments. However, because of incomplete process understanding and limits of the forcing data, model simulations remain uncertain. To quantify this uncertainty a multimodel ensemble of nine large-scale hydrological models was compared to observed runoff from 426 small catchments in Europe. The ensemble was built within the framework of the European Union Water and Global Change (WATCH) project. The models were driven with the same atmospheric forcing data. Models were evaluated with respect to their ability to capture the interannual variability of spatially aggregated annual time series of five runoff percentiles--derived from daily time series--including annual low and high flows. Overall, the models capture the interannual variability of low, mean, and high flows well. However, errors in the mean and standard deviation, as well as differences in performance between the models, became increasingly pronounced for low runoff percentiles, reflecting the uncertainty associated with the representation of hydrological processes, such as the depletion of soil moisture stores. The large spread in model performance implies that any single model should be applied with caution as there is a great risk of biased conclusions. However, this large spread is contrasted by the good overall performance of the ensemble mean. It is concluded that the ensemble mean is a pragmatic and reliable estimator of spatially aggregated time series of annual low, mean, and high flows across Europe.

The planetary boundaries framework defines the "safe operating space for humanity" represented by nine global processes that can destabilize the Earth System if perturbed. The water planetary boundary attempts to provide a global limit to anthropogenic water cycle modifications, but it has been challenging to translate and apply it to the regional and local scales at which water problems and management typically occur. We develop a cross‐scale approach by which the water planetary boundary could guide sustainable water management and governance at subglobal contexts defined by physical features (e.g., watershed or aquifer), political borders (e.g., city, nation, or group of nations), or commercial entities (e.g., corporation, trade group, or financial institution). The application of the water planetary boundary at these subglobal contexts occurs via two approaches: (i) calculating fair shares, in which local water cycle modifications are compared to that context's allocation of the global safe operating space, taking into account biophysical, socioeconomic, and ethical considerations; and (ii) defining a local safe operating space, in which interactions between water stores and Earth System components are used to define local boundaries required for sustaining the local water system in stable conditions, which we demonstrate with a case study of the Cienaga Grande de Santa Marta wetlands in Colombia. By harmonizing these two approaches, the water planetary boundary can ensure that water cycle modifications remain within both local and global boundaries and complement existing water management and governance approaches.

The planetary boundaries framework defines the "safe operating space for humanity" represented by nine global processes that can destabilize the Earth System if perturbed. The water planetary boundary attempts to provide a global limit to anthropogenic water cycle modifications, but it has been challenging to translate and apply it to the regional and local scales at which water problems and management typically occur. We develop a cross-scale approach by which the water planetary boundary could guide sustainable water management and governance at subglobal contexts defined by physical features (e.g., watershed or aquifer), political borders (e.g., city, nation, or group of nations), or commercial entities (e.g., corporation, trade group, or financial institution). The application of the water planetary boundary at these subglobal contexts occurs via two approaches: (i) calculating fair shares, in which local water cycle modifications are compared to that context's allocation of the global safe operating space, taking into account biophysical, socioeconomic, and ethical considerations; and (ii) defining a local safe operating space, in which interactions between water stores and Earth System components are used to define local boundaries required for sustaining the local water system in stable conditions, which we demonstrate with a case study of the Cienaga Grande de Santa Marta wetlands in Colombia. By harmonizing these two approaches, the water planetary boundary can ensure that water cycle modifications remain within both local and global boundaries and complement existing water management and governance approaches. ; Peer reviewed

The planetary boundaries framework defines the "safe operating space for humanity" represented by nine global processes that can destabilize the Earth System if perturbed. The water planetary boundary attempts to provide a global limit to anthropogenic water cycle modifications, but it has been challenging to translate and apply it to the regional and local scales at which water problems and management typically occur. We develop a cross-scale approach by which the water planetary boundary could guide sustainable water management and governance at subglobal contexts defined by physical features (e.g., watershed or aquifer), political borders (e.g., city, nation, or group of nations), or commercial entities (e.g., corporation, trade group, or financial institution). The application of the water planetary boundary at these subglobal contexts occurs via two approaches: (i) calculating fair shares, in which local water cycle modifications are compared to that context's allocation of the global safe operating space, taking into account biophysical, socioeconomic, and ethical considerations; and (ii) defining a local safe operating space, in which interactions between water stores and Earth System components are used to define local boundaries required for sustaining the local water system in stable conditions, which we demonstrate with a case study of the Cienaga Grande de Santa Marta wetlands in Colombia. By harmonizing these two approaches, the water planetary boundary can ensure that water cycle modifications remain within both local and global boundaries and complement existing water management and governance approaches. © 2020 The Authors.