Pub Date : 2024-12-12DOI: 10.1038/s43247-024-01930-6
Yuanchao Fan, Kaighin A. McColl
Previous studies projected an increasing risk of uncompensable heat stress indoors in a warming climate. However, little is known about the timing and extent of this risk for those engaged in essential outdoor activities, such as water collection and farming. Here, we employ a physically-based human energy balance model, which considers radiative, wind, and key physiological effects, to project global risk of uncompensable heat stress outdoors using bias-corrected climate model outputs. Focusing on farmers (approximately 850 million people), our model shows that an ensemble median 2.8% (15%) would be subject to several days of uncompensable heat stress yearly at 2 (4) °C of warming relative to preindustrial. Focusing on people who must walk outside to access drinking water (approximately 700 million people), 3.4% (23%) would be impacted at 2 (4) °C of warming. Outdoor work would need to be completed at night or in the early morning during these events. Farmers and people collecting drinking water outside are projected to be at risk of not achieving sufficient heat dissipation to maintain a stable body temperature at 2 degrees Celsius of global warming, according to an analysis based on a physically based model and heat stress scenarios.
{"title":"Widespread outdoor exposure to uncompensable heat stress with warming","authors":"Yuanchao Fan, Kaighin A. McColl","doi":"10.1038/s43247-024-01930-6","DOIUrl":"10.1038/s43247-024-01930-6","url":null,"abstract":"Previous studies projected an increasing risk of uncompensable heat stress indoors in a warming climate. However, little is known about the timing and extent of this risk for those engaged in essential outdoor activities, such as water collection and farming. Here, we employ a physically-based human energy balance model, which considers radiative, wind, and key physiological effects, to project global risk of uncompensable heat stress outdoors using bias-corrected climate model outputs. Focusing on farmers (approximately 850 million people), our model shows that an ensemble median 2.8% (15%) would be subject to several days of uncompensable heat stress yearly at 2 (4) °C of warming relative to preindustrial. Focusing on people who must walk outside to access drinking water (approximately 700 million people), 3.4% (23%) would be impacted at 2 (4) °C of warming. Outdoor work would need to be completed at night or in the early morning during these events. Farmers and people collecting drinking water outside are projected to be at risk of not achieving sufficient heat dissipation to maintain a stable body temperature at 2 degrees Celsius of global warming, according to an analysis based on a physically based model and heat stress scenarios.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":" ","pages":"1-13"},"PeriodicalIF":8.1,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01930-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142811351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-12DOI: 10.1038/s43247-024-01934-2
Yinglin Tian, Domenico Giaquinto, Giorgia Di Capua, Judith N. Claassen, Javed Ali, Hao Li, Carlo De Michele
Changes in hot and dry extremes in central Europe have been attributed to atmospheric circulation anomalies and land-atmosphere interactions. However, the strength of the underlying causal links and their historical trends have not been quantified. Here, we use Causal Effect Networks (based on the Peter and Clark momentary conditional independence algorithm) and show that hot extreme events in central Europe are driven primarily by anomalous atmospheric patterns and soil water deficiency. Dry extreme events are mainly induced by anomalous atmospheric patterns and soil moisture memory, and only marginally by temperature changes. We find that in the period 1979–2020, the influence of dry soil on temperature has been amplified by 67% during compound hot and dry extremes, while the impact of atmospheric drivers on soil moisture has intensified by 50% (36%) during compound (single) extremes. This work highlights the strengthened causal links of compound hot and dry extremes with their underlying drivers under global warming, which can lead to non-linear interactions and increase adaptation challenges. Central Europe experiences hot and dry extreme events due to atmospheric and surface anomalies, with dry soil’s impact on temperature increasing by up to 67% and atmospheric drivers’ impact on soil moisture increasing by up to 50% between 1979 and 2020, according to a Causal Effect Networks analysis.
{"title":"Historical changes in the Causal Effect Networks of compound hot and dry extremes in central Europe","authors":"Yinglin Tian, Domenico Giaquinto, Giorgia Di Capua, Judith N. Claassen, Javed Ali, Hao Li, Carlo De Michele","doi":"10.1038/s43247-024-01934-2","DOIUrl":"10.1038/s43247-024-01934-2","url":null,"abstract":"Changes in hot and dry extremes in central Europe have been attributed to atmospheric circulation anomalies and land-atmosphere interactions. However, the strength of the underlying causal links and their historical trends have not been quantified. Here, we use Causal Effect Networks (based on the Peter and Clark momentary conditional independence algorithm) and show that hot extreme events in central Europe are driven primarily by anomalous atmospheric patterns and soil water deficiency. Dry extreme events are mainly induced by anomalous atmospheric patterns and soil moisture memory, and only marginally by temperature changes. We find that in the period 1979–2020, the influence of dry soil on temperature has been amplified by 67% during compound hot and dry extremes, while the impact of atmospheric drivers on soil moisture has intensified by 50% (36%) during compound (single) extremes. This work highlights the strengthened causal links of compound hot and dry extremes with their underlying drivers under global warming, which can lead to non-linear interactions and increase adaptation challenges. Central Europe experiences hot and dry extreme events due to atmospheric and surface anomalies, with dry soil’s impact on temperature increasing by up to 67% and atmospheric drivers’ impact on soil moisture increasing by up to 50% between 1979 and 2020, according to a Causal Effect Networks analysis.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":" ","pages":"1-14"},"PeriodicalIF":8.1,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01934-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142811333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-10DOI: 10.1038/s43247-024-01914-6
Tim Repke, Finn Müller-Hansen, Emily Cox, Jan C. Minx
Scaling up CO2 removal is crucial to achieve net-zero targets and limit global warming. To engage with publics and ensure a social licence to deploy large-scale carbon dioxide removal (CDR), better understanding of public perceptions of these technologies is necessary. Here, we analyse attention and sentiments towards ten CDR methods using Twitter data from 2010 to 2022. Attention towards CDR has grown exponentially, particularly in recent years. Overall, the discourse on CDR has become more positive, except for BECCS. Conventional CDR methods are the most discussed and receive more positive sentiments. Various types of users engage with CDR on Twitter to different degrees: While users posting little about CDR pay more attention to methods with biological sinks, frequently engaged users focus more on novel CDR methods. Our results complement survey studies by showing how awareness grows and perceptions change over time. Discourse on carbon dioxide removal on social media has become positive over time, except for bioenergy with carbon capture and storage, with 31 percent of tweets from infrequent users, which make up 78 percent of all users, according to an analysis of Twitter (now X) data from 2010 to 2022.
{"title":"Attention and positive sentiments towards carbon dioxide removal have grown on social media over the past decade","authors":"Tim Repke, Finn Müller-Hansen, Emily Cox, Jan C. Minx","doi":"10.1038/s43247-024-01914-6","DOIUrl":"10.1038/s43247-024-01914-6","url":null,"abstract":"Scaling up CO2 removal is crucial to achieve net-zero targets and limit global warming. To engage with publics and ensure a social licence to deploy large-scale carbon dioxide removal (CDR), better understanding of public perceptions of these technologies is necessary. Here, we analyse attention and sentiments towards ten CDR methods using Twitter data from 2010 to 2022. Attention towards CDR has grown exponentially, particularly in recent years. Overall, the discourse on CDR has become more positive, except for BECCS. Conventional CDR methods are the most discussed and receive more positive sentiments. Various types of users engage with CDR on Twitter to different degrees: While users posting little about CDR pay more attention to methods with biological sinks, frequently engaged users focus more on novel CDR methods. Our results complement survey studies by showing how awareness grows and perceptions change over time. Discourse on carbon dioxide removal on social media has become positive over time, except for bioenergy with carbon capture and storage, with 31 percent of tweets from infrequent users, which make up 78 percent of all users, according to an analysis of Twitter (now X) data from 2010 to 2022.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":" ","pages":"1-11"},"PeriodicalIF":8.1,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01914-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142798593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-10DOI: 10.1038/s43247-024-01873-y
Jian-Jhih Chen, Gen K. Li, Marcus Lin, Justin A. Nghiem, Ziyue Yu, Tianshu Kong, Heather A. Donnelly, Noah P. Snyder, Hanqin Tian, Michael P. Lamb, Xingchen Tony Wang
Anthropogenic nitrogen inputs from the Mississippi-Atchafalaya River Basin have caused substantial environmental challenges in the northern Gulf of Mexico, such as coastal eutrophication, harmful algal blooms, and seasonal hypoxia. Addressing these issues requires a better understanding of the complex sources of nitrogen, which include fertilizers, groundwater, manure, and sewage. In this study, we analyzed the nitrogen isotopic composition of dissolved nitrate and particulate nitrogen from the Wax Lake Delta, a major distributary of the Mississippi-Atchafalaya River Basin that flows into the Gulf of Mexico. Our findings revealed that during the wet season, δ15N values of both nitrate and particulate nitrogen were consistently 2-3‰ lower compared to the dry season. This suggests that fertilizer-derived nitrogen, which has lower δ15N, is predominantly exported to the Gulf of Mexico during periods of high water discharge. These findings imply that adjusting fertilizer application timing could help reduce nitrogen loading and mitigate its environmental impact on the Gulf of Mexico. Fertilizer-derived nitrogen with low isotopic nitrate and particular matter values is mainly exported to the Gulf of Mexico during wet season, according to an analysis combining hydrographic and nutrient data, and isotope samples.
{"title":"Isotopic evidence for preferential transport of fertilizer nitrogen into the northern Gulf of Mexico during high water discharge","authors":"Jian-Jhih Chen, Gen K. Li, Marcus Lin, Justin A. Nghiem, Ziyue Yu, Tianshu Kong, Heather A. Donnelly, Noah P. Snyder, Hanqin Tian, Michael P. Lamb, Xingchen Tony Wang","doi":"10.1038/s43247-024-01873-y","DOIUrl":"10.1038/s43247-024-01873-y","url":null,"abstract":"Anthropogenic nitrogen inputs from the Mississippi-Atchafalaya River Basin have caused substantial environmental challenges in the northern Gulf of Mexico, such as coastal eutrophication, harmful algal blooms, and seasonal hypoxia. Addressing these issues requires a better understanding of the complex sources of nitrogen, which include fertilizers, groundwater, manure, and sewage. In this study, we analyzed the nitrogen isotopic composition of dissolved nitrate and particulate nitrogen from the Wax Lake Delta, a major distributary of the Mississippi-Atchafalaya River Basin that flows into the Gulf of Mexico. Our findings revealed that during the wet season, δ15N values of both nitrate and particulate nitrogen were consistently 2-3‰ lower compared to the dry season. This suggests that fertilizer-derived nitrogen, which has lower δ15N, is predominantly exported to the Gulf of Mexico during periods of high water discharge. These findings imply that adjusting fertilizer application timing could help reduce nitrogen loading and mitigate its environmental impact on the Gulf of Mexico. Fertilizer-derived nitrogen with low isotopic nitrate and particular matter values is mainly exported to the Gulf of Mexico during wet season, according to an analysis combining hydrographic and nutrient data, and isotope samples.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":" ","pages":"1-9"},"PeriodicalIF":8.1,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01873-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142798574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Urban planners and other stakeholders often view trees as the ultimate panacea for mitigating urban heat stress; however, their cooling efficacy varies globally and is influenced by three primary factors: tree traits, urban morphology, and climate conditions. This study analyzes 182 studies on the cooling effects of urban trees across 17 climates in 110 global cities or regions. Tree implementation reduces peak monthly temperatures to below 26 °C in 83% of the cities. Trees can lower pedestrian-level temperatures by up to 12 °C through large radiation blockage and transpiration. In tropical, temperate, and continental climates, a mixed-use of deciduous and evergreen trees in open urban morphology provides approximately 0.5 °C more cooling than a single species approach. In arid climates, evergreen species predominate and demonstrate more effective cooling within compact urban morphology. Our study offers context-specific greening guidelines for urban planners to harness tree cooling in the face of global warming. Urban trees can lower pedestrian-level air temperature by up to 12 degrees centigrade, and the cooling efficacy depends on background climate, urban morphology, and tree trait, according to a global meta-analysis of 182 studies.
{"title":"Cooling efficacy of trees across cities is determined by background climate, urban morphology, and tree trait","authors":"Haiwei Li, Yongling Zhao, Chenghao Wang, Diana Ürge-Vorsatz, Jan Carmeliet, Ronita Bardhan","doi":"10.1038/s43247-024-01908-4","DOIUrl":"10.1038/s43247-024-01908-4","url":null,"abstract":"Urban planners and other stakeholders often view trees as the ultimate panacea for mitigating urban heat stress; however, their cooling efficacy varies globally and is influenced by three primary factors: tree traits, urban morphology, and climate conditions. This study analyzes 182 studies on the cooling effects of urban trees across 17 climates in 110 global cities or regions. Tree implementation reduces peak monthly temperatures to below 26 °C in 83% of the cities. Trees can lower pedestrian-level temperatures by up to 12 °C through large radiation blockage and transpiration. In tropical, temperate, and continental climates, a mixed-use of deciduous and evergreen trees in open urban morphology provides approximately 0.5 °C more cooling than a single species approach. In arid climates, evergreen species predominate and demonstrate more effective cooling within compact urban morphology. Our study offers context-specific greening guidelines for urban planners to harness tree cooling in the face of global warming. Urban trees can lower pedestrian-level air temperature by up to 12 degrees centigrade, and the cooling efficacy depends on background climate, urban morphology, and tree trait, according to a global meta-analysis of 182 studies.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":" ","pages":"1-14"},"PeriodicalIF":8.1,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01908-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142798551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-09DOI: 10.1038/s43247-024-01887-6
Serena Lipari, Karthik Balaguru, Julian Rice, Sha Feng, Wenwei Xu, Larry K. Berg, David Judi
The vulnerability of US offshore wind energy to tropical cyclones is a pressing concern, particularly along the Atlantic and Gulf Coasts, key areas for offshore wind energy development. Assessing the impact of projected climate change on tropical cyclones, and consequently on offshore wind resources, is thus critical for effective risk management. Herein, we investigate the evolving risk to offshore wind turbines posed by Atlantic tropical cyclones in a non-stationary climate using a synthetic tropical cyclone model. Integrated with climate model simulations, projections show widespread increases in tropical cyclone exposure, with historical 20-year storms occurring every ~12.7 years on average, increasing in intensity by about 9.3 ms−1. Subsequent fragility analysis reveals that the probabilities of turbine yielding and buckling from a 20-year tropical cyclone could increase by about 37% and 13%, respectively, with regional increases reaching up to 51%. These findings carry substantial implications for the operation and future expansion of offshore wind farms. Climate change increases US offshore wind energy vulnerability to tropical cyclones, with turbine yielding and buckling probabilities rising by 37% and 13% resulting from a 20-year storm, according to a synthetic tropical cyclone model analysis.
{"title":"Amplified threat of tropical cyclones to US offshore wind energy in a changing climate","authors":"Serena Lipari, Karthik Balaguru, Julian Rice, Sha Feng, Wenwei Xu, Larry K. Berg, David Judi","doi":"10.1038/s43247-024-01887-6","DOIUrl":"10.1038/s43247-024-01887-6","url":null,"abstract":"The vulnerability of US offshore wind energy to tropical cyclones is a pressing concern, particularly along the Atlantic and Gulf Coasts, key areas for offshore wind energy development. Assessing the impact of projected climate change on tropical cyclones, and consequently on offshore wind resources, is thus critical for effective risk management. Herein, we investigate the evolving risk to offshore wind turbines posed by Atlantic tropical cyclones in a non-stationary climate using a synthetic tropical cyclone model. Integrated with climate model simulations, projections show widespread increases in tropical cyclone exposure, with historical 20-year storms occurring every ~12.7 years on average, increasing in intensity by about 9.3 ms−1. Subsequent fragility analysis reveals that the probabilities of turbine yielding and buckling from a 20-year tropical cyclone could increase by about 37% and 13%, respectively, with regional increases reaching up to 51%. These findings carry substantial implications for the operation and future expansion of offshore wind farms. Climate change increases US offshore wind energy vulnerability to tropical cyclones, with turbine yielding and buckling probabilities rising by 37% and 13% resulting from a 20-year storm, according to a synthetic tropical cyclone model analysis.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":" ","pages":"1-10"},"PeriodicalIF":8.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01887-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142798579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-09DOI: 10.1038/s43247-024-01871-0
Kathleen C. Whitson, Peta Callaghan, David Thorpe, Anastasia Ejova
Since non-violent activism is known to be effective in achieving policy change, organisations seeking to encourage climate activism would benefit from an evidence base describing activism behaviours, motivators, and barriers among people higher, lower, and in between in terms of climate activism involvement. We surveyed 519 Australians alarmed by climate change regarding participation in 18 activism behaviours. A latent class analysis identified three activism levels: Least (23%), Moderate (55%), and Most (22%). The Most Active participants were at least 75% likely to engage in 13 behaviours. The only demographic difference between classes is that participants in the Least Active class were younger. Across classes, the most common reported motivators related to issue importance and action efficacy. Reported barriers were more behaviour-specific, with frequent references to lack of experience and knowledge for financial activism and engagement with climate organisations. Six practical applications for promoting climate activism are discussed. Australians alarmed by climate change report the same motivators for their chosen behaviors, but barriers differ across behaviors and do not depend on the individual’s breadth of activity, according to an analysis that combines a survey of 519 individuals and a statistical approach.
{"title":"Three profiles of Australian climate change activism have both unique and overlapping motivators and barriers","authors":"Kathleen C. Whitson, Peta Callaghan, David Thorpe, Anastasia Ejova","doi":"10.1038/s43247-024-01871-0","DOIUrl":"10.1038/s43247-024-01871-0","url":null,"abstract":"Since non-violent activism is known to be effective in achieving policy change, organisations seeking to encourage climate activism would benefit from an evidence base describing activism behaviours, motivators, and barriers among people higher, lower, and in between in terms of climate activism involvement. We surveyed 519 Australians alarmed by climate change regarding participation in 18 activism behaviours. A latent class analysis identified three activism levels: Least (23%), Moderate (55%), and Most (22%). The Most Active participants were at least 75% likely to engage in 13 behaviours. The only demographic difference between classes is that participants in the Least Active class were younger. Across classes, the most common reported motivators related to issue importance and action efficacy. Reported barriers were more behaviour-specific, with frequent references to lack of experience and knowledge for financial activism and engagement with climate organisations. Six practical applications for promoting climate activism are discussed. Australians alarmed by climate change report the same motivators for their chosen behaviors, but barriers differ across behaviors and do not depend on the individual’s breadth of activity, according to an analysis that combines a survey of 519 individuals and a statistical approach.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":" ","pages":"1-9"},"PeriodicalIF":8.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01871-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142798591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Optimizing hydropower generation from the Nile upstream mega-dams during prolonged droughts while minimizing the downstream water deficit is the cornerstone in resolving the ongoing major water conflict in the Eastern Nile River Basin. A decade of negotiation and mediation has been unsuccessful, mainly due to the hydraulic uncertainties associated with operating the Grand Ethiopian Renaissance Dam during prolonged droughts. Based on the negotiation outcomes, we provide comprehensive assessments of the efficiency of multiple drought-mitigation policies for the impact of dam operation. Our results suggest it can generate almost optimal hydropower without a noticeable downstream deficit during wet, average, and temporary drought flow conditions. For prolonged drought, we identify an ideal operation policy allowing the Grand Ethiopian Renaissance Dam to generate a sustainable energy of 87% of its optimal hydropower without generating additional downstream water deficit. Furthermore, we provide four intermediate policies demonstrating enhanced upstream hydropower generation while minimizing dam-induced downstream water deficits. Our findings attempt to bridge the negotiation disparities in the Nile hydropower mega-dams operations during prolonged drought and foster an actionable and collaborative framework. Nile’s river mega-dams can operate collaboratively to generate upstream sustainable hydropower and minimize downstream water deficit during drought events, according to an analysis that combines the water resources systems model and policy scenarios.
{"title":"Grand Ethiopian Renaissance Dam can generate sustainable hydropower while minimizing downstream water deficit during prolonged droughts","authors":"Essam Heggy, Abotalib Z. Abotalib, Jongeun You, Emmanuel Hanert, Mohamed Ramah","doi":"10.1038/s43247-024-01821-w","DOIUrl":"10.1038/s43247-024-01821-w","url":null,"abstract":"Optimizing hydropower generation from the Nile upstream mega-dams during prolonged droughts while minimizing the downstream water deficit is the cornerstone in resolving the ongoing major water conflict in the Eastern Nile River Basin. A decade of negotiation and mediation has been unsuccessful, mainly due to the hydraulic uncertainties associated with operating the Grand Ethiopian Renaissance Dam during prolonged droughts. Based on the negotiation outcomes, we provide comprehensive assessments of the efficiency of multiple drought-mitigation policies for the impact of dam operation. Our results suggest it can generate almost optimal hydropower without a noticeable downstream deficit during wet, average, and temporary drought flow conditions. For prolonged drought, we identify an ideal operation policy allowing the Grand Ethiopian Renaissance Dam to generate a sustainable energy of 87% of its optimal hydropower without generating additional downstream water deficit. Furthermore, we provide four intermediate policies demonstrating enhanced upstream hydropower generation while minimizing dam-induced downstream water deficits. Our findings attempt to bridge the negotiation disparities in the Nile hydropower mega-dams operations during prolonged drought and foster an actionable and collaborative framework. Nile’s river mega-dams can operate collaboratively to generate upstream sustainable hydropower and minimize downstream water deficit during drought events, according to an analysis that combines the water resources systems model and policy scenarios.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":" ","pages":"1-15"},"PeriodicalIF":8.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01821-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142798599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-05DOI: 10.1038/s43247-024-01925-3
Jie Liang, Manuel Chevalier, Keshao Liu, Amedea Perfumo, Mingda Wang, Haichao Xie, Juzhi Hou, Ulrike Herzschuh, Fahu Chen
Bacterial lipid branched glycerol dialkyl glycerol tetraethers (brGDGTs) are a valuable tool for reconstructing past temperatures. However, a gap remains regarding the influence of bacterial communities on brGDGT profiles. Here, we identified two distinct patterns of brGDGTs from the surface sediments of 38 Tibetan Plateau lakes using an unsupervised clustering technique. Further investigation revealed that salinity and pH significantly change bacterial community composition, affecting brGDGT profiles and causing brGDGT-based temperatures to be overestimated by up to 2.7 ± 0.7 °C in haloalkaline environments. We subsequently used the trained clustering model to examine the patterns of bacterial assemblages in the global lacustrine brGDGT dataset, confirming the global applicability of our approach. We finally applied our approach to Holocene brGDGT records from the Tibetan Plateau, showing that shifts in bacterial clusters amplified temperature variations over timescales. Our findings demonstrate that microbial ecology can robustly diagnose and constrain site-specific discrepancies in temperature reconstruction. Salinity and pH-driven variations in microbial communities significantly affect bacterial lipid compositions, leading to temperature overestimations in reconstructions, based on machine learning clustering of lake sediment data and bacterial analysis.
{"title":"Discrepancies in lacustrine bacterial lipid temperature reconstructions explained by microbial ecology","authors":"Jie Liang, Manuel Chevalier, Keshao Liu, Amedea Perfumo, Mingda Wang, Haichao Xie, Juzhi Hou, Ulrike Herzschuh, Fahu Chen","doi":"10.1038/s43247-024-01925-3","DOIUrl":"10.1038/s43247-024-01925-3","url":null,"abstract":"Bacterial lipid branched glycerol dialkyl glycerol tetraethers (brGDGTs) are a valuable tool for reconstructing past temperatures. However, a gap remains regarding the influence of bacterial communities on brGDGT profiles. Here, we identified two distinct patterns of brGDGTs from the surface sediments of 38 Tibetan Plateau lakes using an unsupervised clustering technique. Further investigation revealed that salinity and pH significantly change bacterial community composition, affecting brGDGT profiles and causing brGDGT-based temperatures to be overestimated by up to 2.7 ± 0.7 °C in haloalkaline environments. We subsequently used the trained clustering model to examine the patterns of bacterial assemblages in the global lacustrine brGDGT dataset, confirming the global applicability of our approach. We finally applied our approach to Holocene brGDGT records from the Tibetan Plateau, showing that shifts in bacterial clusters amplified temperature variations over timescales. Our findings demonstrate that microbial ecology can robustly diagnose and constrain site-specific discrepancies in temperature reconstruction. Salinity and pH-driven variations in microbial communities significantly affect bacterial lipid compositions, leading to temperature overestimations in reconstructions, based on machine learning clustering of lake sediment data and bacterial analysis.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":" ","pages":"1-14"},"PeriodicalIF":8.1,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01925-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-05DOI: 10.1038/s43247-024-01936-0
Meng Zhang, Yanhong Gao, Mingfang Ting, Yan Yu, Guoyin Wang
Land use is key in regulating surface temperature, yet these relationships are often obscured by long-term mean responses. Here we employed numerical multi-model results to investigate the response of the surface temperature to land use change, especially its lower tails corresponding to boreal winter. The surface temperature decrease in the lower tails can exhibit up to ten times greater than the mean response to land use change over both the historical and future periods. Downward longwave radiation has emerged as the most remarkable contributing factor in controlling surface temperature change in mid-high latitudes of the Northern Hemisphere. Land use change can modify surface energy balance through land-atmosphere firstly, thereby regulate spatial patterns of water vapor and cloud cover in the Northern Hemisphere through teleconnection. The unity of local and remote effects influences the levels of downward longwave radiation and altering surface temperature at mid-high latitudes in extreme cold seasons. Downward longwave radiation significantly influences the cooling response in northern mid-high latitudes to land use change, influenced by changes in water vapor and cloud cover, according to multi-model ensemble results.
{"title":"Land-use induced changes in extreme temperature predominantly influenced by downward longwave radiation","authors":"Meng Zhang, Yanhong Gao, Mingfang Ting, Yan Yu, Guoyin Wang","doi":"10.1038/s43247-024-01936-0","DOIUrl":"10.1038/s43247-024-01936-0","url":null,"abstract":"Land use is key in regulating surface temperature, yet these relationships are often obscured by long-term mean responses. Here we employed numerical multi-model results to investigate the response of the surface temperature to land use change, especially its lower tails corresponding to boreal winter. The surface temperature decrease in the lower tails can exhibit up to ten times greater than the mean response to land use change over both the historical and future periods. Downward longwave radiation has emerged as the most remarkable contributing factor in controlling surface temperature change in mid-high latitudes of the Northern Hemisphere. Land use change can modify surface energy balance through land-atmosphere firstly, thereby regulate spatial patterns of water vapor and cloud cover in the Northern Hemisphere through teleconnection. The unity of local and remote effects influences the levels of downward longwave radiation and altering surface temperature at mid-high latitudes in extreme cold seasons. Downward longwave radiation significantly influences the cooling response in northern mid-high latitudes to land use change, influenced by changes in water vapor and cloud cover, according to multi-model ensemble results.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":" ","pages":"1-11"},"PeriodicalIF":8.1,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01936-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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