Pub Date : 2024-08-29DOI: 10.1038/s43247-024-01628-9
Clemens Schmitt, Iuliana Vasiliev, Niels Meijer, Julia Brugger, Stefanie Kaboth-Bahr, André Bahr, Andreas Mulch
Eocene hyperthermal events reflect profound perturbations of the global carbon cycle. Most of our knowledge about their onset, timing, and rates originates from marine records. Hence, the pacing and magnitude of hyperthermal continental warming remains largely unaccounted for due to a lack of high-resolution climate records. Here we use terrestrial biomarkers and carbon isotopes retrieved from varved lake deposits of the UNESCO World Heritage site ‘Messel Fossil Pit’ (Germany) to quantify sub-millennial to millennial-scale temperature and carbon isotope changes across hyperthermal event C21n-H1 (47.2 million years ago). Our results show maximum warming of ca. 3.5 °C during C21n-H1. We propose that two components are responsible for the warming pattern across the hyperthermal: (1) the massive release of greenhouse gases into the atmosphere-ocean system and (2) half-precession orbital forcing indicated by ~12.000-year temperature cycles. The carbon isotope record of bulk organic matter indicates a sharp, 7‰ decrease at the peak of the hyperthermal, corresponding to increased organic carbon content and a shift in the lake algal community. Collectively, our proxy data reveal the structure of continental temperature response during the hyperthermal event that is characterized by overall warming with a superimposed pattern of sub-orbital scale temperature fluctuations. During an early middle Eocene hyperthermal event warming of up to 3.5 °C, probably in response to greenhouse gas release and orbital forcing, was recorded in varved lake sediments from Messel Fossil Pit, Germany.
{"title":"Eocene maar sediments record warming of up to 3.5 °C during a hyperthermal event 47.2 million years ago","authors":"Clemens Schmitt, Iuliana Vasiliev, Niels Meijer, Julia Brugger, Stefanie Kaboth-Bahr, André Bahr, Andreas Mulch","doi":"10.1038/s43247-024-01628-9","DOIUrl":"10.1038/s43247-024-01628-9","url":null,"abstract":"Eocene hyperthermal events reflect profound perturbations of the global carbon cycle. Most of our knowledge about their onset, timing, and rates originates from marine records. Hence, the pacing and magnitude of hyperthermal continental warming remains largely unaccounted for due to a lack of high-resolution climate records. Here we use terrestrial biomarkers and carbon isotopes retrieved from varved lake deposits of the UNESCO World Heritage site ‘Messel Fossil Pit’ (Germany) to quantify sub-millennial to millennial-scale temperature and carbon isotope changes across hyperthermal event C21n-H1 (47.2 million years ago). Our results show maximum warming of ca. 3.5 °C during C21n-H1. We propose that two components are responsible for the warming pattern across the hyperthermal: (1) the massive release of greenhouse gases into the atmosphere-ocean system and (2) half-precession orbital forcing indicated by ~12.000-year temperature cycles. The carbon isotope record of bulk organic matter indicates a sharp, 7‰ decrease at the peak of the hyperthermal, corresponding to increased organic carbon content and a shift in the lake algal community. Collectively, our proxy data reveal the structure of continental temperature response during the hyperthermal event that is characterized by overall warming with a superimposed pattern of sub-orbital scale temperature fluctuations. During an early middle Eocene hyperthermal event warming of up to 3.5 °C, probably in response to greenhouse gas release and orbital forcing, was recorded in varved lake sediments from Messel Fossil Pit, Germany.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01628-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091218","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 : 2024-08-29DOI: 10.1038/s43247-024-01635-w
Shihao Cui, Pengfei Liu, Haonan Guo, Claudia Kalla Nielsen, Johannes Wilhelmus Maria Pullens, Qing Chen, Lorenzo Pugliese, Shubiao Wu
Wetlands are the largest and most uncertain biological source of atmospheric methane, with hydrological fluctuations exacerbating this uncertainty. Here we critically explore the complex relationship between hydrological fluctuations and methane emissions in wetlands by integrating observations from 31 FLUXNET wetland sites with a comprehensive literature review. We present the prevalence and patterns of water table fluctuations and their contribution to uncertainty in methane fluxes. We also highlight key pathways through which these fluctuations affect methane production and emission, such as soil redox heterogeneity, changes in substrate availability and alternative electron acceptor pool, the contribution of different methane transport pathways, and the non-linear responses of community structure and activity of methanogens and methanotrophs to hydrological fluctuations. This review aims to improve the accuracy of wetland methane emission reports by carefully assessing biogeochemical kinetics under hydrological fluctuations. Water table fluctuations in wetlands impact methane production and emissions via biotic and abiotic pathways including soil redox, substrate availability, electron flow, gas transport, and microbial community structure, according to the analysis of observational data from 31 wetland sites and a broad literature review.
{"title":"Wetland hydrological dynamics and methane emissions","authors":"Shihao Cui, Pengfei Liu, Haonan Guo, Claudia Kalla Nielsen, Johannes Wilhelmus Maria Pullens, Qing Chen, Lorenzo Pugliese, Shubiao Wu","doi":"10.1038/s43247-024-01635-w","DOIUrl":"10.1038/s43247-024-01635-w","url":null,"abstract":"Wetlands are the largest and most uncertain biological source of atmospheric methane, with hydrological fluctuations exacerbating this uncertainty. Here we critically explore the complex relationship between hydrological fluctuations and methane emissions in wetlands by integrating observations from 31 FLUXNET wetland sites with a comprehensive literature review. We present the prevalence and patterns of water table fluctuations and their contribution to uncertainty in methane fluxes. We also highlight key pathways through which these fluctuations affect methane production and emission, such as soil redox heterogeneity, changes in substrate availability and alternative electron acceptor pool, the contribution of different methane transport pathways, and the non-linear responses of community structure and activity of methanogens and methanotrophs to hydrological fluctuations. This review aims to improve the accuracy of wetland methane emission reports by carefully assessing biogeochemical kinetics under hydrological fluctuations. Water table fluctuations in wetlands impact methane production and emissions via biotic and abiotic pathways including soil redox, substrate availability, electron flow, gas transport, and microbial community structure, according to the analysis of observational data from 31 wetland sites and a broad literature review.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01635-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091185","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 : 2024-08-28DOI: 10.1038/s43247-024-01585-3
Tom Staton, Nicholas Davison, Sally Westaway, Lisa Arguile, Nina Adams, Victor Aguilera, Lillie Bellamy, Alysoun Bolger, Richard Gantlett, Steven Jacobs, Niamh Noone, Joanna T. Staley, Laurence G. Smith
Organic food systems are recognised as an important component in meeting United Nations’ (UN) Sustainable Development Goals. A leverage points perspective can help to identify approaches which have the potential to facilitate transformative systemic change towards organic and sustainable farming. Using fuzzy cognitive maps developed from expert stakeholder opinions, we modelled a system of drivers of organic food production and consumption in the United Kingdom, according to the UN Sustainability Assessment of Food and Agriculture systems framework. The most influential concepts in the uptake of organic systems were related to system norms and values and social structures, such as short-term economic thinking, landowner engagement, and relationships with certification bodies. However, in a scenario analysis, organic stakeholders identified relatively shallower leverage points as more likely to change under a sustainable future, resulting in limited systemic change. This demonstrates the need for policies targeting system norms, values and social structures relating to food systems to facilitate the transition to organic and sustainable farming. Short-term economic thinking, landowner engagement with organic farming, and consumers’ willingness to pay for organic food are the most influential factors in organic food production and consumption scale-up, according to an analysis combining data from expert workshops and fuzzy cognitive maps.
{"title":"Leverage points for the uptake of organic food production and consumption in the United Kingdom","authors":"Tom Staton, Nicholas Davison, Sally Westaway, Lisa Arguile, Nina Adams, Victor Aguilera, Lillie Bellamy, Alysoun Bolger, Richard Gantlett, Steven Jacobs, Niamh Noone, Joanna T. Staley, Laurence G. Smith","doi":"10.1038/s43247-024-01585-3","DOIUrl":"10.1038/s43247-024-01585-3","url":null,"abstract":"Organic food systems are recognised as an important component in meeting United Nations’ (UN) Sustainable Development Goals. A leverage points perspective can help to identify approaches which have the potential to facilitate transformative systemic change towards organic and sustainable farming. Using fuzzy cognitive maps developed from expert stakeholder opinions, we modelled a system of drivers of organic food production and consumption in the United Kingdom, according to the UN Sustainability Assessment of Food and Agriculture systems framework. The most influential concepts in the uptake of organic systems were related to system norms and values and social structures, such as short-term economic thinking, landowner engagement, and relationships with certification bodies. However, in a scenario analysis, organic stakeholders identified relatively shallower leverage points as more likely to change under a sustainable future, resulting in limited systemic change. This demonstrates the need for policies targeting system norms, values and social structures relating to food systems to facilitate the transition to organic and sustainable farming. Short-term economic thinking, landowner engagement with organic farming, and consumers’ willingness to pay for organic food are the most influential factors in organic food production and consumption scale-up, according to an analysis combining data from expert workshops and fuzzy cognitive maps.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01585-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091183","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 : 2024-08-28DOI: 10.1038/s43247-024-01636-9
Zhongxiang Fang, Wenmin Zhang, Lanhui Wang, Guy Schurgers, Philippe Ciais, Josep Peñuelas, Martin Brandt, Hui Yang, Ke Huang, Qiu Shen, Fensholt Rasmus
Vegetation growth may adapt to climate warming by adjusting the relationship between photosynthetic capacity and temperature. However, changes in the optimal temperature for ecosystem productivity during recent decades of warming remain uncertain. Here we provide empirical evidence that global optimal temperature increased at a rate of 0.017 ± 0.002 °C y−1 from 1982 to 2016, using multiple datasets of satellite-derived productivity and climate variables. Model simulations show that the optimal temperature will increase by 0.027 ± 0.001 °C y−1 until the end of 21st century. The global increasing optimal temperature is consistent with increasing mean air temperatures and model simulations further confirm the key role of temperature in regulating changes in optimal temperature, while being co-regulated by other factors, such as CO2 and precipitation. These results suggest that vegetation is acclimating to warming and that the negative impacts of climate change on ecosystem productivity may be less severe than previously thought. Climate change may have less negative impact on terrestrial ecosystem productivity as vegetation growth adapts to climatic warming, increasing optimal temperature from 1982 to 2016, according to evidence from satellite-derived ecosystem productivity, climate variables, and ecosystem simulations.
{"title":"Global increase in the optimal temperature for the productivity of terrestrial ecosystems","authors":"Zhongxiang Fang, Wenmin Zhang, Lanhui Wang, Guy Schurgers, Philippe Ciais, Josep Peñuelas, Martin Brandt, Hui Yang, Ke Huang, Qiu Shen, Fensholt Rasmus","doi":"10.1038/s43247-024-01636-9","DOIUrl":"10.1038/s43247-024-01636-9","url":null,"abstract":"Vegetation growth may adapt to climate warming by adjusting the relationship between photosynthetic capacity and temperature. However, changes in the optimal temperature for ecosystem productivity during recent decades of warming remain uncertain. Here we provide empirical evidence that global optimal temperature increased at a rate of 0.017 ± 0.002 °C y−1 from 1982 to 2016, using multiple datasets of satellite-derived productivity and climate variables. Model simulations show that the optimal temperature will increase by 0.027 ± 0.001 °C y−1 until the end of 21st century. The global increasing optimal temperature is consistent with increasing mean air temperatures and model simulations further confirm the key role of temperature in regulating changes in optimal temperature, while being co-regulated by other factors, such as CO2 and precipitation. These results suggest that vegetation is acclimating to warming and that the negative impacts of climate change on ecosystem productivity may be less severe than previously thought. Climate change may have less negative impact on terrestrial ecosystem productivity as vegetation growth adapts to climatic warming, increasing optimal temperature from 1982 to 2016, according to evidence from satellite-derived ecosystem productivity, climate variables, and ecosystem simulations.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01636-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091177","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 : 2024-08-28DOI: 10.1038/s43247-024-01634-x
Pablo Busch, Paulo Rocha, Kyung Jin Lee, Luis Abdón Cifuentes, Xiao Hui Tai
Exposure to fine particulate matter (PM2.5) is known to cause adverse health outcomes. Most of the evidence has been derived from developed countries, with lower pollution levels and different demographics and comorbidities from the rest of the world. Here we leverage new satellite-based measurements of PM2.5, combined with comprehensive public records in Chile, to study the effect of PM2.5 pollution on elderly mortality. We find that a 10 μg/m3 monthly increase in PM2.5 exposure is associated with a 1.7% increase (95% C.I.: 1.1–2.4%) in all-cause mortality for individuals aged 75+. Satellite-based measurements allow us to comprehensively investigate heterogeneous effects. We find remarkably similar effect sizes across baseline exposure, rural and urban areas, income, and over time, demonstrating consistency in the evidence on mortality effects of PM2.5 exposure. The most notable source of heterogeneity is geographical, with effects closer to 5% in the center-south and in the metropolitan area. For Chilean people aged 75 and over, a monthly increase in the levels of fine particulate matter, a form of air pollution, are consistently associated with higher all-cause mortality, based on an analysis of satellite PM2.5 data and health records.
{"title":"Short-term exposure to fine particulate pollution and elderly mortality in Chile","authors":"Pablo Busch, Paulo Rocha, Kyung Jin Lee, Luis Abdón Cifuentes, Xiao Hui Tai","doi":"10.1038/s43247-024-01634-x","DOIUrl":"10.1038/s43247-024-01634-x","url":null,"abstract":"Exposure to fine particulate matter (PM2.5) is known to cause adverse health outcomes. Most of the evidence has been derived from developed countries, with lower pollution levels and different demographics and comorbidities from the rest of the world. Here we leverage new satellite-based measurements of PM2.5, combined with comprehensive public records in Chile, to study the effect of PM2.5 pollution on elderly mortality. We find that a 10 μg/m3 monthly increase in PM2.5 exposure is associated with a 1.7% increase (95% C.I.: 1.1–2.4%) in all-cause mortality for individuals aged 75+. Satellite-based measurements allow us to comprehensively investigate heterogeneous effects. We find remarkably similar effect sizes across baseline exposure, rural and urban areas, income, and over time, demonstrating consistency in the evidence on mortality effects of PM2.5 exposure. The most notable source of heterogeneity is geographical, with effects closer to 5% in the center-south and in the metropolitan area. For Chilean people aged 75 and over, a monthly increase in the levels of fine particulate matter, a form of air pollution, are consistently associated with higher all-cause mortality, based on an analysis of satellite PM2.5 data and health records.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01634-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091176","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 : 2024-08-28DOI: 10.1038/s43247-024-01627-w
Piero A. B. de Sampaio, Zheng-Xiang Li, Luc S. Doucet
Earth’s mantle isotopic composition is highly heterogeneous, with enriched and depleted regions1–3 shaped by a complex history of depletion and re-enrichment over 4.5 billion years. The spatial configuration of large-scale heterogeneity in the mantle is not random4,5, but the timing and mechanisms that caused such heterogeneity are still debated2,6,7. We compiled radiogenic isotope data of mid-ocean ridge and plume-induced basalts from both present-day and past oceans for the past 900 million years of the relatively isotopically enriched African mantle domain. Our analysis shows that oceanic rocks of the African mantle domain exhibit a relatively homogenous composition similar to the prevalent mantle estimates (PREMA8) until ca. 350 million years ago when plume-derived rocks started becoming isotopically enriched with maximum enrichment reached in the mid-Cretaceous. From that point in time, plume-derived rocks shift toward depletion, getting closer to the prevalent mantle value. The enrichment trend is interpreted to have resulted from the recycling of crustal material during the assembly and the early stage of a break-up of Gondwana and Pangea, whereas the subsequent depletion trend is due to the outward retreat of the subduction girdle during the break-up of Pangea, thus both are legacies of geodynamic processes related to the supercontinent cycle. Geochemical enrichment and depletion patterns in the African mantle domain from the last 900 million years may be attributed to focused recycling of crustal material as part of the supercontinent cycle, supported by isotopic data in palegeographically constrained ophiolitic rocks.
{"title":"Global mantle isotopic anomalies linked to supercontinent-superocean evolution for the past 700 million years","authors":"Piero A. B. de Sampaio, Zheng-Xiang Li, Luc S. Doucet","doi":"10.1038/s43247-024-01627-w","DOIUrl":"10.1038/s43247-024-01627-w","url":null,"abstract":"Earth’s mantle isotopic composition is highly heterogeneous, with enriched and depleted regions1–3 shaped by a complex history of depletion and re-enrichment over 4.5 billion years. The spatial configuration of large-scale heterogeneity in the mantle is not random4,5, but the timing and mechanisms that caused such heterogeneity are still debated2,6,7. We compiled radiogenic isotope data of mid-ocean ridge and plume-induced basalts from both present-day and past oceans for the past 900 million years of the relatively isotopically enriched African mantle domain. Our analysis shows that oceanic rocks of the African mantle domain exhibit a relatively homogenous composition similar to the prevalent mantle estimates (PREMA8) until ca. 350 million years ago when plume-derived rocks started becoming isotopically enriched with maximum enrichment reached in the mid-Cretaceous. From that point in time, plume-derived rocks shift toward depletion, getting closer to the prevalent mantle value. The enrichment trend is interpreted to have resulted from the recycling of crustal material during the assembly and the early stage of a break-up of Gondwana and Pangea, whereas the subsequent depletion trend is due to the outward retreat of the subduction girdle during the break-up of Pangea, thus both are legacies of geodynamic processes related to the supercontinent cycle. Geochemical enrichment and depletion patterns in the African mantle domain from the last 900 million years may be attributed to focused recycling of crustal material as part of the supercontinent cycle, supported by isotopic data in palegeographically constrained ophiolitic rocks.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01627-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091178","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 : 2024-08-28DOI: 10.1038/s43247-024-01609-y
Przemysław Gorzelak, Jarosław Stolarski, Paweł Bącal, Philippe Dubois, Dorota Kołbuk
Shifts in the magnesium to calcium ratio of seawater in the geological history are thought to have profoundly affected biomineralization of marine invertebrates, including some echinoderms, which changed their skeletal mineralogy from high-magnesium to low-magnesium calcite and vice versa. Here we report on experiments that aimed to investigate the effect of ambient seawater magnesium to calcium ratio on magnesium to calcium ratio and nanomechanical properties in the spines of two echinoid species (Arbacia lixula and Paracentrotus lividus). We found that echinoids cultured in seawater with a low magnesium to calcium ratio produced a skeleton with lower both magnesium content and nanohardness than those of the control specimens incubated under normal (high) magnesium to calcium ratio conditions. These results may suggest that at certain times in the geological past (during the so-called calcite seas) sea urchins with decreased skeletal magnesium contents were more susceptible to damage due to physical disturbances, predation and post-mortem taphonomic processes. Increased skeletal hardness of echinoids from the so-called aragonite seas is expected to enhance their taphonomic potential, thus, to some extent, mitigates the preservation bias related to increased solubility of high-magnesium calcite. Oceanic chemistry changes have made echinoderm skeletons weaker, making them more prone to damage from physical disturbances, predatory attacks, and taphonomic processes, according to experimental, geochemical, and nanoindentation analyses.
{"title":"Calcium-rich seawater affects the mechanical properties of echinoderm skeleton","authors":"Przemysław Gorzelak, Jarosław Stolarski, Paweł Bącal, Philippe Dubois, Dorota Kołbuk","doi":"10.1038/s43247-024-01609-y","DOIUrl":"10.1038/s43247-024-01609-y","url":null,"abstract":"Shifts in the magnesium to calcium ratio of seawater in the geological history are thought to have profoundly affected biomineralization of marine invertebrates, including some echinoderms, which changed their skeletal mineralogy from high-magnesium to low-magnesium calcite and vice versa. Here we report on experiments that aimed to investigate the effect of ambient seawater magnesium to calcium ratio on magnesium to calcium ratio and nanomechanical properties in the spines of two echinoid species (Arbacia lixula and Paracentrotus lividus). We found that echinoids cultured in seawater with a low magnesium to calcium ratio produced a skeleton with lower both magnesium content and nanohardness than those of the control specimens incubated under normal (high) magnesium to calcium ratio conditions. These results may suggest that at certain times in the geological past (during the so-called calcite seas) sea urchins with decreased skeletal magnesium contents were more susceptible to damage due to physical disturbances, predation and post-mortem taphonomic processes. Increased skeletal hardness of echinoids from the so-called aragonite seas is expected to enhance their taphonomic potential, thus, to some extent, mitigates the preservation bias related to increased solubility of high-magnesium calcite. Oceanic chemistry changes have made echinoderm skeletons weaker, making them more prone to damage from physical disturbances, predatory attacks, and taphonomic processes, according to experimental, geochemical, and nanoindentation analyses.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01609-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091225","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 : 2024-08-27DOI: 10.1038/s43247-024-01632-z
Fuencisla Cañadas, Dominic Papineau, Thomas J. Algeo, Chao Li
The Ediacaran ocean (635-541 million years ago) is typically viewed as a stagnant, redox-stratified ocean with low phosphorus availability. However, this contradicts the high total organic carbon (up to 15 wt%) recorded in the upper Ediacaran Doushantuo Formation in South China. Here, we present a quantitative reconstruction of primary productivity and sediment total organic carbon using basin-scale simulations based on various redox-nutrient scenarios. Our results indicate that oceanic upwelling was the primary driver of enhanced primary productivity, with estimates over 2.5 times the modern ocean’s average, providing quantitative evidence for oceanic circulation in the Ediacaran Nanhua Basin. Our results also indicate the development of spatially linked but opposing redox trends, i.e., a ‘redox anticouple’, whereby the expansion of the oxic surface layer occurred concurrently with intensification of deep-water anoxia due to enhanced PP in surface and its consumption of oxidants in underlying waters. This model may explain the conflicting redox records across the Nanhua Basin. Our findings explain the unusually high rates of organic matter production and preservation in the low-pO2 Ediacaran ocean and provide a mechanism for its progressive oxygenation. “Increased organic matter production during the late Ediacaran is likely the result of an enhanced rate of primary production caused by a high rate of oceanic upwelling, suggests a basin-scale simulation under different environmental conditions, for the Doushantuo Formation in South China.”
{"title":"Upwelling-driven high organic production in the late Ediacaran","authors":"Fuencisla Cañadas, Dominic Papineau, Thomas J. Algeo, Chao Li","doi":"10.1038/s43247-024-01632-z","DOIUrl":"10.1038/s43247-024-01632-z","url":null,"abstract":"The Ediacaran ocean (635-541 million years ago) is typically viewed as a stagnant, redox-stratified ocean with low phosphorus availability. However, this contradicts the high total organic carbon (up to 15 wt%) recorded in the upper Ediacaran Doushantuo Formation in South China. Here, we present a quantitative reconstruction of primary productivity and sediment total organic carbon using basin-scale simulations based on various redox-nutrient scenarios. Our results indicate that oceanic upwelling was the primary driver of enhanced primary productivity, with estimates over 2.5 times the modern ocean’s average, providing quantitative evidence for oceanic circulation in the Ediacaran Nanhua Basin. Our results also indicate the development of spatially linked but opposing redox trends, i.e., a ‘redox anticouple’, whereby the expansion of the oxic surface layer occurred concurrently with intensification of deep-water anoxia due to enhanced PP in surface and its consumption of oxidants in underlying waters. This model may explain the conflicting redox records across the Nanhua Basin. Our findings explain the unusually high rates of organic matter production and preservation in the low-pO2 Ediacaran ocean and provide a mechanism for its progressive oxygenation. “Increased organic matter production during the late Ediacaran is likely the result of an enhanced rate of primary production caused by a high rate of oceanic upwelling, suggests a basin-scale simulation under different environmental conditions, for the Doushantuo Formation in South China.”","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01632-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142078005","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 : 2024-08-27DOI: 10.1038/s43247-024-01624-z
Yu Zhuang, Binod Dawadi, Jakob Steiner, Rajesh Kumar Dash, Yves Bühler, Jessica Munch, Perry Bartelt
On 25 April 2015, the Gorkha earthquake triggered a large rock-ice avalanche and an air blast disaster in the Langtang Valley, Nepal. More than 350 people were killed or left missing. Here we reconstruct the evolution of the Langtang avalanche-air blast using field investigations and numerical modeling and examine the influence of two primary climate-related phenomena: snowfall anomalies and warm temperatures. Our findings suggest a deep snow cover fosters the formation of a dispersed avalanche, which increases the mobility and destructive power of the powder cloud air blast. Elevated air temperatures intensify meltwater production and lubricate the flowing mass. Both mechanisms contributed to the Langtang disaster. Our study underscores the essential impact of snow cover and air temperature on the risk assessment of high-altitude rock-ice avalanches, highlighting how seasonal and climatic variations affect avalanche runout and air blast dynamics. The 2015 Langtang Avalanche in Nepal was exacerbated by deep snow cover and warm temperatures, amplifying the mobility, destructive force, and lubricating effect of melt water on the flowing mass, according to analysis of avalanche runout under various air temperature and snow depth conditions.
{"title":"An earthquake-triggered avalanche in Nepal in 2015 was exacerbated by climate variability and snowfall anomalies","authors":"Yu Zhuang, Binod Dawadi, Jakob Steiner, Rajesh Kumar Dash, Yves Bühler, Jessica Munch, Perry Bartelt","doi":"10.1038/s43247-024-01624-z","DOIUrl":"10.1038/s43247-024-01624-z","url":null,"abstract":"On 25 April 2015, the Gorkha earthquake triggered a large rock-ice avalanche and an air blast disaster in the Langtang Valley, Nepal. More than 350 people were killed or left missing. Here we reconstruct the evolution of the Langtang avalanche-air blast using field investigations and numerical modeling and examine the influence of two primary climate-related phenomena: snowfall anomalies and warm temperatures. Our findings suggest a deep snow cover fosters the formation of a dispersed avalanche, which increases the mobility and destructive power of the powder cloud air blast. Elevated air temperatures intensify meltwater production and lubricate the flowing mass. Both mechanisms contributed to the Langtang disaster. Our study underscores the essential impact of snow cover and air temperature on the risk assessment of high-altitude rock-ice avalanches, highlighting how seasonal and climatic variations affect avalanche runout and air blast dynamics. The 2015 Langtang Avalanche in Nepal was exacerbated by deep snow cover and warm temperatures, amplifying the mobility, destructive force, and lubricating effect of melt water on the flowing mass, according to analysis of avalanche runout under various air temperature and snow depth conditions.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01624-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091173","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}
Compound heat anomalies associated with humidity, such as compound hot-dry events and hot-wet events, pose greater health risks than single heat anomalies. Here, we utilize ambulance dispatch data along with air temperature and relative humidity to study human impacts on these events in China. We show that relying solely on temperature without considering humidity may underestimate the health risks of these events on populations. Over the past 40 years, anthropogenic activities have increased hot-dry events by 2.34 times and decreased hot-wet events by 0.63 times, especially in the Yangtze River region, compared to natural forcing. We also speculate that, in the future up to 2060, under the carbon-neutral scenario, the frequencies of high health-risk hot-dry events and hot-wet events caused by human activities can be reduced by one-half and over one-fifth, respectively, compared to the high-emissions scenario. These findings provide guidance for assessing health risks under global warming. Over the past 40 years, human activities in China have led to high health-risk compound heat anomalies, especially in the Yangtze River region, which could be reduced by 2060, if carbon-neutral scenarios are implemented, according to analysis of the ambulance dispatch data, air temperature, and relative humidity.
{"title":"Changes caused by human activities in the high health-risk hot-dry and hot-wet events in China","authors":"Haoxin Yao, Liang Zhao, Yiling He, Wei Dong, Xinyong Shen, Jingsong Wang, Yamin Hu, Jian Ling, Ziniu Xiao, Cunrui Huang","doi":"10.1038/s43247-024-01625-y","DOIUrl":"10.1038/s43247-024-01625-y","url":null,"abstract":"Compound heat anomalies associated with humidity, such as compound hot-dry events and hot-wet events, pose greater health risks than single heat anomalies. Here, we utilize ambulance dispatch data along with air temperature and relative humidity to study human impacts on these events in China. We show that relying solely on temperature without considering humidity may underestimate the health risks of these events on populations. Over the past 40 years, anthropogenic activities have increased hot-dry events by 2.34 times and decreased hot-wet events by 0.63 times, especially in the Yangtze River region, compared to natural forcing. We also speculate that, in the future up to 2060, under the carbon-neutral scenario, the frequencies of high health-risk hot-dry events and hot-wet events caused by human activities can be reduced by one-half and over one-fifth, respectively, compared to the high-emissions scenario. These findings provide guidance for assessing health risks under global warming. Over the past 40 years, human activities in China have led to high health-risk compound heat anomalies, especially in the Yangtze River region, which could be reduced by 2060, if carbon-neutral scenarios are implemented, according to analysis of the ambulance dispatch data, air temperature, and relative humidity.","PeriodicalId":10530,"journal":{"name":"Communications Earth & Environment","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43247-024-01625-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091204","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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