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- ItemTrade-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, AnjaForests 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.
- ItemFinancial Feasibility of Water Conservation in Agriculture(Hoboken, NJ : Wiley-Blackwell, 2021) Siderius, Christian; Biemans, Hester; Conway, Declan; Immerzeel, Walter; Jaegermeyr, Jonas; Ahmad, Bashir; Hellegers, PetraGlobal 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.
- ItemGrounding 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, NunoIntegrated 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
- ItemUnderstanding 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.
- ItemReduced Complexity Model Intercomparison Project Phase 2: Synthesizing Earth System Knowledge for Probabilistic Climate Projections(Hoboken, NJ : Wiley-Blackwell, 2021) Nicholls, Z.; Meinshausen, M.; Lewis, J.; Corradi, M. Rojas; Dorheim, K.; Gasser, T.; Gieseke, R.; Hope, A.P.; Leach, N.J.; McBride, L.A.; Quilcaille, Y.; Rogelj, J.; Salawitch, R.J.; Samset, B.H.; Sandstad, M.; Shiklomanov, A.; Skeie, R.B.; Smith, C.J.; Smith, S.J.; Su, X.; Tsutsui, J.; Vega-Westhoff, B.; Woodard, D.L.Over the last decades, climate science has evolved rapidly across multiple expert domains. Our best tools to capture state-of-the-art knowledge in an internally self-consistent modeling framework are the increasingly complex fully coupled Earth System Models (ESMs). However, computational limitations and the structural rigidity of ESMs mean that the full range of uncertainties across multiple domains are difficult to capture with ESMs alone. The tools of choice are instead more computationally efficient reduced complexity models (RCMs), which are structurally flexible and can span the response dynamics across a range of domain-specific models and ESM experiments. Here we present Phase 2 of the Reduced Complexity Model Intercomparison Project (RCMIP Phase 2), the first comprehensive intercomparison of RCMs that are probabilistically calibrated with key benchmark ranges from specialized research communities. Unsurprisingly, but crucially, we find that models which have been constrained to reflect the key benchmarks better reflect the key benchmarks. Under the low-emissions SSP1-1.9 scenario, across the RCMs, median peak warming projections range from 1.3 to 1.7°C (relative to 1850-1900, using an observationally based historical warming estimate of 0.8°C between 1850-1900 and 1995-2014). Further developing methodologies to constrain these projection uncertainties seems paramount given the international community's goal to contain warming to below 1.5°C above preindustrial in the long-term. Our findings suggest that users of RCMs should carefully evaluate their RCM, specifically its skill against key benchmarks and consider the need to include projections benchmarks either from ESM results or other assessments to reduce divergence in future projections.
- ItemCascading Hazards in the Aftermath of Australia's 2019/2020 Black Summer Wildfires(Hoboken, NJ : Wiley-Blackwell, 2021) Kemter, M.; Fischer, M.; Luna, L.V.; Schönfeldt, E.; Vogel, J.; Banerjee, A.; Korup, O.; Thonicke, K.Following an unprecedented drought, Australia's 2019/2020 “Black Summer” fire season caused severe damage, gravely impacting both humans and ecosystems, and increasing susceptibility to other hazards. Heavy precipitation in early 2020 led to flooding and runoff that entrained ash and soil in burned areas, increasing sediment concentration in rivers, and reducing water quality. We exemplify this hazard cascade in a catchment in New South Wales by mapping burn severity, flood, and rainfall recurrence; estimating changes in soil erosion; and comparing them with river turbidity data. We show that following the extreme drought and wildfires, even moderate rain and floods led to undue increases in soil erosion and reductions in water quality. While natural risk analysis and planning commonly focuses on a single hazard, we emphasize the need to consider the entire hazard cascade, and highlight the impacts of ongoing climate change beyond its direct effect on wildfires.
- ItemQuantifying 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, JianyunWith 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.
- ItemA 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.
- ItemGiving Legs to Handprint Thinking: Foundations for Evaluating the Good We Do(Hoboken, NJ : Wiley-Blackwell, 2020) Guillaume, Joseph H.A.; Sojamo, Suvi; Porkka, Miina; Gerten, Dieter; Jalava, Mika; Lankoski, Leena; Lehikoinen, Elina; Lettenmeier, Michael; Pfister, Stephan; Usva, Kirsi; Wada, Yoshihide; Kummu, MattiIn environmental management and sustainability there is an increasing interest in measurement and accounting of beneficial impact—as an incentive to action, as a communication tool, and to move toward a positive, constructive approach focused on opportunities rather than problems. One approach uses the metaphor of a “handprint,” complementing the notion of environmental footprints, which have been widely adopted for impact measurement and accounting. We analyze this idea by establishing core principles of handprint thinking: Handprint encourages actions with positive impacts and connects to analyses of footprint reductions but adds value to them and addresses the issue of what action should be taken. We also identify five key questions that need to be addressed and decisions that need to be made in performing a (potentially quantitative) handprint assessment, related to scoping of the improvement to be made, how it is achieved, and how credit is assigned, taking into account constraints on action. A case study of the potential water footprint reduction of an average Finn demonstrates how handprint thinking can be a natural extension of footprint reduction analyses. We find that there is a diversity of possible handprint assessments that have the potential to encourage doing good. Their common foundation is “handprint thinking.”. © 2020 The Authors.
- ItemIdentifying 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, RicardaKeeping 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.