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Now showing 1 - 10 of 12
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    Understanding the Drivers of Coastal Flood Exposure and Risk From 1860 to 2100
    (Hoboken, NJ : Wiley-Blackwell, 2022) Lincke, Daniel; Hinkel, Jochen; Mengel, Matthias; Nicholls, Robert J.
    Global coastal flood exposure (population and assets) has been growing since the beginning of the industrial age and is likely to continue to grow through 21st century. Three main drivers are responsible: (a) climate-related mean sea-level change, (b) vertical land movement contributing to relative sea-level rise, and (c) socio-economic development. This paper attributes growing coastal exposure and flood risk from 1860 to 2100 to these three drivers. For historic flood exposure (1860–2005) we find that the roughly six-fold increase in population exposure and 53-fold increase in asset exposure are almost completely explained by socio-economic development (>97% for population and >99% for assets). For future exposure (2005–2100), assuming a middle-of-the-road regionalized socio-economic scenario (SSP2) without coastal migration and sea-level rise according to RCP2.6 and RCP6.0, climate-change induced sea-level rise will become the most important driver for the growth in population exposure, while growth in asset exposure will still be mainly determined by socio-economic development.
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    A High-End Estimate of Sea Level Rise for Practitioners
    (Hoboken, NJ : Wiley-Blackwell, 2022) van de Wal, R.S.W.; Nicholls, R J.; Behar, D.; McInnes, K.; Stammer, D.; Lowe, J.A.; Church, J.A.; DeConto, R.; Fettweis, X.; Goelzer, H.; Haasnoot, M.; Haigh, I.D.; Hinkel, J.; Horton, B.P.; James, T.S.; Jenkins, A.; LeCozannet, G.; Levermann, A.; Lipscomb, W.H.; Marzeion, B.; Pattyn, F.; Payne, A.J.; Pfeffer, W.T.; Price, S.F.; Seroussi, H.; Sun, S.; Veatch, W.; White, K.
    Sea level rise (SLR) is a long-lasting consequence of climate change because global anthropogenic warming takes centuries to millennia to equilibrate for the deep ocean and ice sheets. SLR projections based on climate models support policy analysis, risk assessment and adaptation planning today, despite their large uncertainties. The central range of the SLR distribution is estimated by process-based models. However, risk-averse practitioners often require information about plausible future conditions that lie in the tails of the SLR distribution, which are poorly defined by existing models. Here, a community effort combining scientists and practitioners builds on a framework of discussing physical evidence to quantify high-end global SLR for practitioners. The approach is complementary to the IPCC AR6 report and provides further physically plausible high-end scenarios. High-end estimates for the different SLR components are developed for two climate scenarios at two timescales. For global warming of +2°C in 2100 (RCP2.6/SSP1-2.6) relative to pre-industrial values our high-end global SLR estimates are up to 0.9 m in 2100 and 2.5 m in 2300. Similarly, for a (RCP8.5/SSP5-8.5), we estimate up to 1.6 m in 2100 and up to 10.4 m in 2300. The large and growing differences between the scenarios beyond 2100 emphasize the long-term benefits of mitigation. However, even a modest 2°C warming may cause multi-meter SLR on centennial time scales with profound consequences for coastal areas. Earlier high-end assessments focused on instability mechanisms in Antarctica, while here we emphasize the importance of the timing of ice shelf collapse around Antarctica. This is highly uncertain due to low understanding of the driving processes. Hence both process understanding and emission scenario control high-end SLR.
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    Grounding Social Foundations for Integrated Assessment Models of Climate Change
    (Hoboken, NJ : Wiley-Blackwell, 2020) Mathias, Jean‐Denis; Debeljak, Marko; Deffuant, Guillaume; Diemer, Arnaud; Dierickx, Florian; Donges, Jonathan F.; Gladkykh, Ganna; Heitzig, Jobst; Holtz, Georg; Obergassel, Wolfgang; Pellaud, Francine; Sánchez, Angel; Trajanov, Aneta; Videira, Nuno
    Integrated assessment models (IAMs) are commonly used by decision makers in order to derive climate policies. IAMs are currently based on climate-economics interactions, whereas the role of social system has been highlighted to be of prime importance on the implementation of climate policies. Beyond existing IAMs, we argue that it is therefore urgent to increase efforts in the integration of social processes within IAMs. For achieving such a challenge, we present some promising avenues of research based on the social branches of economics. We finally present the potential implications yielded by such social IAMs. ©2020. The Authors. Earth's Future published by Wiley Periodicals LLC on behalf of American Geophysical Union
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    Projecting Exposure to Extreme Climate Impact Events Across Six Event Categories and Three Spatial Scales
    (Hoboken, NJ : Wiley-Blackwell, 2020) Lange, Stefan; Volkholz, Jan; Geiger, Tobias; Zhao, Fang; Vega, Iliusi; Veldkamp, Ted; Reyer, Christopher P.O.; Warszawski, Lila; Huber, Veronika; Jägermeyr, Jonas; Schewe, Jacob; Bresch, David N.; Büchner, Matthias; Chang, Jinfeng; Ciais, Philippe; Dury, Marie; Emanuel, Kerry; Folberth, Christian; Gerten, Dieter; Gosling, Simon N.; Grillakis, Manolis; Hanasaki, Naota; Henrot, Alexandra-Jane; Hickler, Thomas; Honda, Yasushi; Ito, Akihiko; Khabarov, Nikolay; Koutroulis, Aristeidis; Liu, Wenfeng; Müller, Christoph; Nishina, Kazuya; Ostberg, Sebastian; Müller Schmied, Hannes; Seneviratne, Sonia I.; Stacke, Tobias; Steinkamp, Jörg; Thiery, Wim; Wada, Yoshihide; Willner, Sven; Yang, Hong; Yoshikawa, Minoru; Yue, Chao; Frieler, Katja
    The extent and impact of climate-related extreme events depend on the underlying meteorological, hydrological, or climatological drivers as well as on human factors such as land use or population density. Here we quantify the pure effect of historical and future climate change on the exposure of land and population to extreme climate impact events using an unprecedentedly large ensemble of harmonized climate impact simulations from the Inter-Sectoral Impact Model Intercomparison Project phase 2b. Our results indicate that global warming has already more than doubled both the global land area and the global population annually exposed to all six categories of extreme events considered: river floods, tropical cyclones, crop failure, wildfires, droughts, and heatwaves. Global warming of 2°C relative to preindustrial conditions is projected to lead to a more than fivefold increase in cross-category aggregate exposure globally. Changes in exposure are unevenly distributed, with tropical and subtropical regions facing larger increases than higher latitudes. The largest increases in overall exposure are projected for the population of South Asia. ©2020. The Authors.
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    Quantifying Water Scarcity in Northern China Within the Context of Climatic and Societal Changes and South-to-North Water Diversion
    (Hoboken, NJ : Wiley-Blackwell, 2020) Yin, Yuanyuan; Wang, Lei; Wang, Zhongjing; Tang, Qiuhong; Piao, Shilong; Chen, Deliang; Xia, Jun; Conradt, Tobias; Liu, Junguo; Wada, Yoshihide; Cai, Ximing; Xie, Zhenghui; Duan, Qingyun; Li, Xiuping; Zhou, Jing; Zhang, Jianyun
    With the increasing pressure from population growth and economic development, northern China (NC) faces a grand challenge of water scarcity, which can be further exacerbated by climatic and societal changes. The South-to-North Water Diversion (SNWD) project is designed to mitigate the water scarcity in NC. However, few studies have quantified the impact of the SNWD on water scarcity within the context of climatic and societal changes and its potential effects on economic and agricultural food in the region. We used water supply stress index (WaSSI) to quantify water scarcity within the context of environmental change in NC and developed a method to estimate the economic and agricultural impacts of the SNWD. Focuses were put on alleviating the water supply shortage and economic and agricultural benefits for the water-receiving NC. We find that societal changes, especially economic growth, are the major contributors to water scarcity in NC during 2009–2099. To completely mitigate the water scarcity of NC, at least an additional water supply of 13 billion m3/year (comparable to the annual diversion water by SNWD Central Route) will be necessary. Although SNWD alone cannot provide the full solution to NC's water shortage in next few decades, it can significantly alleviate the water supply stress in NC (particularly Beijing), considerably increasing the agricultural production (more than 115 Tcal/year) and bringing economic benefits (more than 51 billion RMB/year) through supplying industrial and domestic water use. Additionally, the transfer project could have impacts on the ecological environment in the exporting regions. ©2020. The Authors.
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    Identifying a Safe and Just Corridor for People and the Planet
    (Hoboken, NJ : Wiley-Blackwell, 2021) Rockström, Johan; Gupta, Joyeeta; Lenton, Timothy M.; Qin, Dahe; Lade, Steven J.; Abrams, Jesse F.; Jacobson, Lisa; Rocha, Juan C.; Zimm, Caroline; Bai, Xuemei; Bala, Govindasamy; Bringezu, Stefan; Broadgate, Wendy; Bunn, Stuart E.; DeClerck, Fabrice; Ebi, Kristie L.; Gong, Peng; Gordon, Chris; Kanie, Norichika; Liverman, Diana M.; Nakicenovic, Nebojsa; Obura, David; Ramanathan, Veerabhadran; Verburg, Peter H.; van Vuuren, Detlef P.; Winkelmann, Ricarda
    Keeping the Earth system in a stable and resilient state, to safeguard Earth's life support systems while ensuring that Earth's benefits, risks, and related responsibilities are equitably shared, constitutes the grand challenge for human development in the Anthropocene. Here, we describe a framework that the recently formed Earth Commission will use to define and quantify target ranges for a “safe and just corridor” that meets these goals. Although “safe” and “just” Earth system targets are interrelated, we see safe as primarily referring to a stable Earth system and just targets as being associated with meeting human needs and reducing exposure to risks. To align safe and just dimensions, we propose to address the equity dimensions of each safe target for Earth system regulating systems and processes. The more stringent of the safe or just target ranges then defines the corridor. Identifying levers of social transformation aimed at meeting the safe and just targets and challenges associated with translating the corridor to actors at multiple scales present scope for future work.
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    The COVID‐19 Pandemic Not Only Poses Challenges, but Also Opens Opportunities for Sustainable Transformation
    (Hoboken, NJ : Wiley-Blackwell, 2021) Pradhan, Prajal; Subedi, Daya Raj; Khatiwada, Dilip; Joshi, Kirti Kusum; Kafle, Sagar; Chhetri, Raju Pandit; Dhakal, Shobhakar; Gautam, Ambika Prasad; Khatiwada, Padma Prasad; Mainaly, Jony; Onta, Sharad; Pandey, Vishnu Prasad; Parajuly, Keshav; Pokharel, Sijal; Satyal, Poshendra; Singh, Devendra Raj; Talchabhadel, Rocky; Tha, Rupesh; Thapa, Bhesh Raj; Adhikari, Kamal; Adhikari, Shankar; Chandra Bastakoti, Ram; Bhandari, Pitambar; Bharati, Saraswoti; Bhusal, Yub Raj; Bahadur BK, Man; Bogati, Ramji; Kafle, Simrin; Khadka, Manohara; Khatiwada, Nawa Raj; Lal, Ajay Chandra; Neupane, Dinesh; Neupane, Kaustuv Raj; Ojha, Rajit; Regmi, Narayan Prasad; Rupakheti, Maheswar; Sapkota, Alka; Sapkota, Rupak; Sharma, Mahashram; Shrestha, Gitta; Shrestha, Indira; Shrestha, Khadga Bahadur; Tandukar, Sarmila; Upadhyaya, Shyam; Kropp, Jürgen P.; Bhuju, Dinesh Raj
    The COVID-19 pandemic has impacted social, economic, and environmental systems worldwide, slowing down and reversing the progress made in achieving the Sustainable Development Goals (SDGs). SDGs belong to the 2030 Agenda to transform our world by tackling humankind's challenges to ensure well-being, economic prosperity, and environmental protection. We explore the potential impacts of the pandemic on SDGs for Nepal. We followed a knowledge co-creation process with experts from various professional backgrounds, involving five steps: online survey, online workshop, assessment of expert's opinions, review and validation, and revision and synthesis. The pandemic has negatively impacted most SDGs in the short term. Particularly, the targets of SDG 1, 4, 5, 8, 9, 10, 11, and 13 have and will continue to have weakly to moderately restricting impacts. However, a few targets of SDG 2, 3, 6, and 11 could also have weakly promoting impacts. The negative impacts have resulted from impeding factors linked to the pandemic. Many of the negative impacts may subside in the medium and long terms. The key five impeding factors are lockdowns, underemployment and unemployment, closure of institutions and facilities, diluted focus and funds for non-COVID-19-related issues, and anticipated reduction in support from development partners. The pandemic has also opened a window of opportunity for sustainable transformation, which is short-lived and narrow. These opportunities are lessons learned for planning and action, socio-economic recovery plan, use of information and communication technologies and the digital economy, reverse migration and “brain gain,” and local governments' exercising authorities.
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    Financial Feasibility of Water Conservation in Agriculture
    (Hoboken, NJ : Wiley-Blackwell, 2021) Siderius, Christian; Biemans, Hester; Conway, Declan; Immerzeel, Walter; Jaegermeyr, Jonas; Ahmad, Bashir; Hellegers, Petra
    Global water use for food production needs to be reduced to remain within planetary boundaries, yet the financial feasibility of crucial measures to reduce water use is poorly quantified. Here, we introduce a novel method to compare the costs of water conservation measures with the added value that reallocation of water savings might generate if used for expansion of irrigation. Based on detailed water accounting through the use of a high-resolution hydrology-crop model, we modify the traditional cost curve approach with an improved estimation of demand and increasing marginal cost per water conservation measure combination, adding a correction to control for impacts on downstream water availability. We apply the method to three major river basins in the Indo-Gangetic plain (Indus, Ganges and Brahmaputra), a major global food producing region but increasingly water stressed. Our analysis shows that at basin level only about 10% (Brahmaputra) to just over 20% (Indus and Ganges) of potential water savings would be realized; the equilibrium price for water is too low to make the majority of water conservation measures cost effective. The associated expansion of irrigated area is moderate, about 7% in the Indus basin, 5% in the Ganges and negligible in the Brahmaputra, but farmers' gross profit increases more substantially, by 11%. Increasing the volumetric cost of irrigation water influences supply and demand in a similar way and has little influence on water reallocation. Controlling for the impact on return flows is important and more than halves the amount of water available for reallocation.
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    Integrating the Water Planetary Boundary With Water Management From Local to Global Scales
    (Hoboken, NJ : Wiley-Blackwell, 2020) Zipper, Samuel C.; Jaramillo, Fernando; Wang‐Erlandsson, Lan; Cornell, Sarah E.; Gleeson, Tom; Porkka, Miina; Häyhä, Tiina; Crépin, Anne‐Sophie; Fetzer, Ingo; Gerten, Dieter; Hoff, Holger; Matthews, Nathanial; Ricaurte‐Villota, Constanza; Kummu, Matti; Wada, Yoshihide; Gordon, Line
    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.
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    Trade-Offs for Climate-Smart Forestry in Europe Under Uncertain Future Climate
    (Hoboken, NJ : Wiley-Blackwell, 2022) Gregor, Konstantin; Knoke, Thomas; Krause, Andreas; Reyer, Christopher P. O.; Lindeskog, Mats; Papastefanou, Phillip; Smith, Benjamin; Lansø, Anne‐Sofie; Rammig, Anja
    Forests mitigate climate change by storing carbon and reducing emissions via substitution effects of wood products. Additionally, they provide many other important ecosystem services (ESs), but are vulnerable to climate change; therefore, adaptation is necessary. Climate-smart forestry combines mitigation with adaptation, whilst facilitating the provision of many ESs. This is particularly challenging due to large uncertainties about future climate. Here, we combined ecosystem modeling with robust multi-criteria optimization to assess how the provision of various ESs (climate change mitigation, timber provision, local cooling, water availability, and biodiversity habitat) can be guaranteed under a broad range of climate futures across Europe. Our optimized portfolios contain 29% unmanaged forests, and implicate a successive conversion of 34% of coniferous to broad-leaved forests (11% vice versa). Coppices practically vanish from Southern Europe, mainly due to their high water requirement. We find the high shares of unmanaged forests necessary to keep European forests a carbon sink while broad-leaved and unmanaged forests contribute to local cooling through biogeophysical effects. Unmanaged forests also pose the largest benefit for biodiversity habitat. However, the increased shares of unmanaged and broad-leaved forests lead to reductions in harvests. This raises the question of how to meet increasing wood demands without transferring ecological impacts elsewhere or enhancing the dependence on more carbon-intensive industries. Furthermore, the mitigation potential of forests depends on assumptions about the decarbonization of other industries and is consequently crucially dependent on the emission scenario. Our findings highlight that trade-offs must be assessed when developing concrete strategies for climate-smart forestry.