Pub Date : 2024-08-05DOI: 10.1088/1748-9326/ad661a
Peiyuan Li and Ashish Sharma
The vertical dimensions of urban morphology, specifically the heights of trees and buildings, exert significant influence on wind flow fields in urban street canyons and the thermal environment of the urban fabric, subsequently affecting the microclimate, noise levels, and air quality. Despite their importance, these critical attributes are less commonly available and rarely utilized in urban climate models compared to planar land use and land cover data. In this study, we explicitly mapped the height of trees and buildings (HiTAB) across the city of Chicago at 1 m spatial resolution using a data fusion approach. This approach integrates high-precision light detection and ranging (LiDAR) cloud point data, building footprint inventory, and multi-band satellite images. Specifically, the digital terrain and surface models were first created from the LiDAR dataset to calculate the height of surface objects, while the rest of the datasets were used to delineate trees and buildings. We validated the derived height information against the existing building database in downtown Chicago and the Meter-scale Urban Land Cover map from the Environmental Protection Agency, respectively. The co-investigation on trees and building heights offers a valuable initiative in the effort to inform urban land surface parameterizations using real-world data. Given their high spatial resolution, the height maps can be adopted in physical-based and data-driven urban models to achieve higher resolution and accuracy while lowering uncertainties. Moreover, our method can be extended to other urban regions, benefiting from the growing availability of high-resolution urban informatics globally. Collectively, these datasets can substantially contribute to future studies on hyper-local weather dynamics, urban heterogeneity, morphology, and planning, providing a more comprehensive understanding of urban environments.
{"title":"Detailed height mapping of trees and buildings (HiTAB) in Chicago and its implications to urban climate studies","authors":"Peiyuan Li and Ashish Sharma","doi":"10.1088/1748-9326/ad661a","DOIUrl":"https://doi.org/10.1088/1748-9326/ad661a","url":null,"abstract":"The vertical dimensions of urban morphology, specifically the heights of trees and buildings, exert significant influence on wind flow fields in urban street canyons and the thermal environment of the urban fabric, subsequently affecting the microclimate, noise levels, and air quality. Despite their importance, these critical attributes are less commonly available and rarely utilized in urban climate models compared to planar land use and land cover data. In this study, we explicitly mapped the height of trees and buildings (HiTAB) across the city of Chicago at 1 m spatial resolution using a data fusion approach. This approach integrates high-precision light detection and ranging (LiDAR) cloud point data, building footprint inventory, and multi-band satellite images. Specifically, the digital terrain and surface models were first created from the LiDAR dataset to calculate the height of surface objects, while the rest of the datasets were used to delineate trees and buildings. We validated the derived height information against the existing building database in downtown Chicago and the Meter-scale Urban Land Cover map from the Environmental Protection Agency, respectively. The co-investigation on trees and building heights offers a valuable initiative in the effort to inform urban land surface parameterizations using real-world data. Given their high spatial resolution, the height maps can be adopted in physical-based and data-driven urban models to achieve higher resolution and accuracy while lowering uncertainties. Moreover, our method can be extended to other urban regions, benefiting from the growing availability of high-resolution urban informatics globally. Collectively, these datasets can substantially contribute to future studies on hyper-local weather dynamics, urban heterogeneity, morphology, and planning, providing a more comprehensive understanding of urban environments.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141937074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-05DOI: 10.1088/1748-9326/ad6918
Yingxiao Sun, Qianrong Ma, Taichen Feng, Zhonghua Qian, Zhiwei Zhu, Chao Li and Guolin Feng
Climatic changes worsen concurrent extreme climate events. In July and August of 2022 and 2020, respectively, unexpected concurrent extreme events occurred in mid-latitude Asia. The sudden and severe consequences highlight the importance of a thorough understanding of the drivers of such extreme events, which is crucial for improving predictions and implementing preventive measures to mitigate future risks. By applying multi-scale window transform methodology, a unique mechanism of multi-scale zonal wind resonance is identified, which manifests as a quasi-stationary co-coupling with low-frequency zonal winds. This resonance leads to barotropic instability, triggering abnormal low-frequency Rossby wave behavior in the entrance and exit regions of the quasi-stationary jet stream. Simultaneously, the intensified meridional wind, coupled with adiabatic atmospheric warming, amplifies baroclinic instability, resulting in an enhanced wave pattern and the high concurrence events of 2022. Under long term future global warming levels of 4 °C, the concurrence, strengthened by multi-scale zonal wind resonance, is expected to persist. The mechanism evident in 2022 plays a broader and more significant role in concurrent events compared to the mechanism in 2020. Under the process of warming, resonance phenomena, as observed in 2022, are projected to become more frequent.
{"title":"Concurrent extremes in mid-latitude Asia triggered by resonance of multi-scale zonal wind","authors":"Yingxiao Sun, Qianrong Ma, Taichen Feng, Zhonghua Qian, Zhiwei Zhu, Chao Li and Guolin Feng","doi":"10.1088/1748-9326/ad6918","DOIUrl":"https://doi.org/10.1088/1748-9326/ad6918","url":null,"abstract":"Climatic changes worsen concurrent extreme climate events. In July and August of 2022 and 2020, respectively, unexpected concurrent extreme events occurred in mid-latitude Asia. The sudden and severe consequences highlight the importance of a thorough understanding of the drivers of such extreme events, which is crucial for improving predictions and implementing preventive measures to mitigate future risks. By applying multi-scale window transform methodology, a unique mechanism of multi-scale zonal wind resonance is identified, which manifests as a quasi-stationary co-coupling with low-frequency zonal winds. This resonance leads to barotropic instability, triggering abnormal low-frequency Rossby wave behavior in the entrance and exit regions of the quasi-stationary jet stream. Simultaneously, the intensified meridional wind, coupled with adiabatic atmospheric warming, amplifies baroclinic instability, resulting in an enhanced wave pattern and the high concurrence events of 2022. Under long term future global warming levels of 4 °C, the concurrence, strengthened by multi-scale zonal wind resonance, is expected to persist. The mechanism evident in 2022 plays a broader and more significant role in concurrent events compared to the mechanism in 2020. Under the process of warming, resonance phenomena, as observed in 2022, are projected to become more frequent.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141936989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1088/1748-9326/ad5f44
Wenying Liao, Vítor V Vasconcelos, Simon A Levin and Michael Oppenheimer
Risks, such as climate change, disease outbreak, geopolitical tension, may exacerbate food insecurity by negatively impacting crop yield. Additional agricultural nitrogen input may partly offset yield losses, with a corresponding increase in nitrogen pollution. The problems of food insecurity and nitrogen pollution are urgent and global but have not been addressed in an integrated fashion. Current efforts to combat food insecurity occur primarily through the United Nations’ World Food Program at the international level, and, at the local community level, through food banks. The international program to monitor and reduce global nitrogen pollution is in its early stage. Food provision and nitrogen pollution reduction from agriculture presents a dual challenge that requires an integrated solution. Here, we propose a cooperative food bank, where membership is a matter of choice and is not coerced. Membership requires participants to reduce nitrogen pollution in agriculture but creates a risk-buffering system, providing food compensation when participants are affected by risk factors. We delineate the structure of the cooperative food bank, its operation, from the short-term mobilization of resources to long-term capacity building. Lastly, we assess the feasibility of its implementation and highlight the potential major roadblocks to its implementation within the current socio-political context. The cooperative food bank showcases a novel solution that simultaneously tackles food insecurity and nitrogen pollution via governance. We hope this proposal will stimulate a research agenda and policy discussions focused on integrated approaches to effective governance regimes for linked socio-environmental problems.
{"title":"Cooperative food bank: a collective insurance regime to govern food insecurity and nitrogen pollution under risk","authors":"Wenying Liao, Vítor V Vasconcelos, Simon A Levin and Michael Oppenheimer","doi":"10.1088/1748-9326/ad5f44","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5f44","url":null,"abstract":"Risks, such as climate change, disease outbreak, geopolitical tension, may exacerbate food insecurity by negatively impacting crop yield. Additional agricultural nitrogen input may partly offset yield losses, with a corresponding increase in nitrogen pollution. The problems of food insecurity and nitrogen pollution are urgent and global but have not been addressed in an integrated fashion. Current efforts to combat food insecurity occur primarily through the United Nations’ World Food Program at the international level, and, at the local community level, through food banks. The international program to monitor and reduce global nitrogen pollution is in its early stage. Food provision and nitrogen pollution reduction from agriculture presents a dual challenge that requires an integrated solution. Here, we propose a cooperative food bank, where membership is a matter of choice and is not coerced. Membership requires participants to reduce nitrogen pollution in agriculture but creates a risk-buffering system, providing food compensation when participants are affected by risk factors. We delineate the structure of the cooperative food bank, its operation, from the short-term mobilization of resources to long-term capacity building. Lastly, we assess the feasibility of its implementation and highlight the potential major roadblocks to its implementation within the current socio-political context. The cooperative food bank showcases a novel solution that simultaneously tackles food insecurity and nitrogen pollution via governance. We hope this proposal will stimulate a research agenda and policy discussions focused on integrated approaches to effective governance regimes for linked socio-environmental problems.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141882874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-30DOI: 10.1088/1748-9326/ad5d0b
Michael Gomez, Caitlin Grady, Lisa Wainger, Raj Cibin, David Abler, Darrell Bosch, Jason Kaye
Excessive nitrogen (N) pollution in the Chesapeake Bay is threatening ecological health. This study presents a multilayer N flow network model where each network layer represents a stage in the production step from raw agricultural commodities such as corn to final products such as packaged meat. We use this model to assess the impacts of alternative future agricultural production and land use changes on multiple pathways of N pollution within the Chesapeake Bay Watershed (CBW). We analyzed N loss via all pathways under multiple future scenarios, considering crop-specific projections based on empirical data and US Department of Agriculture projections. We found two model parameters, fertilizer nitrogen application rate (FNAR) and feed conversion ratio (FCR), to be particularly important for seeing measurable N loss reductions in the Bay. Our results indicate a large increase in N loss under the business-as-usual trajectory in geographic locations with intensive agricultural production. We found that numerous management scenarios including improvements in FNAR and FCR, N losses fall short of the 25% total maximum daily load targets. Our work suggests that achieving the CBW N loss reduction goals will necessitate large deviations from business as usual. Our model also highlights substantial regional variations in nitrogen loss across the U.S., with central regions like the Corn Belt and Central Valley of California experiencing the highest losses from crop-related stages, while eastern areas such as the Chesapeake Bay exhibit major losses from live animal production, underscoring the need for region-specific management strategies. Thus, implementation of effective N management strategies, combined with improved crop residue management, remains pivotal in mitigating N pollution in the Chesapeake Bay.
{"title":"Impacts of future scenarios on the nitrogen loss from agricultural supply chains in the Chesapeake Bay","authors":"Michael Gomez, Caitlin Grady, Lisa Wainger, Raj Cibin, David Abler, Darrell Bosch, Jason Kaye","doi":"10.1088/1748-9326/ad5d0b","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5d0b","url":null,"abstract":"Excessive nitrogen (N) pollution in the Chesapeake Bay is threatening ecological health. This study presents a multilayer N flow network model where each network layer represents a stage in the production step from raw agricultural commodities such as corn to final products such as packaged meat. We use this model to assess the impacts of alternative future agricultural production and land use changes on multiple pathways of N pollution within the Chesapeake Bay Watershed (CBW). We analyzed N loss via all pathways under multiple future scenarios, considering crop-specific projections based on empirical data and US Department of Agriculture projections. We found two model parameters, fertilizer nitrogen application rate (FNAR) and feed conversion ratio (FCR), to be particularly important for seeing measurable N loss reductions in the Bay. Our results indicate a large increase in N loss under the business-as-usual trajectory in geographic locations with intensive agricultural production. We found that numerous management scenarios including improvements in FNAR and FCR, N losses fall short of the 25% total maximum daily load targets. Our work suggests that achieving the CBW N loss reduction goals will necessitate large deviations from business as usual. Our model also highlights substantial regional variations in nitrogen loss across the U.S., with central regions like the Corn Belt and Central Valley of California experiencing the highest losses from crop-related stages, while eastern areas such as the Chesapeake Bay exhibit major losses from live animal production, underscoring the need for region-specific management strategies. Thus, implementation of effective N management strategies, combined with improved crop residue management, remains pivotal in mitigating N pollution in the Chesapeake Bay.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-30DOI: 10.1088/1748-9326/ad5d05
Sara Meerow, Ladd Keith, Malini Roy, Shaylynn Trego
Escalating impacts from climate change and urban heat are increasing the urgency for communities to equitably plan for heat resilience. Cities in the desert Southwest are among the hottest and fastest warming in the U.S., placing them on the front lines of heat planning. Urban heat resilience requires an integrated planning approach that coordinates strategies across the network of plans that shape the built environment and risk patterns. To date, few studies have assessed cities’ progress on heat planning. This research is the first to combine two emerging plan evaluation approaches to examine how networks of plans shape urban heat resilience through case studies of Tempe and Tucson, Arizona. The first methodology, Plan Quality Evaluation for Heat Resilience, adapts existing plan quality assessment approaches to heat. We assess whether plans meet 56 criteria across seven principles of high-quality planning and the types of heat strategies included in the plans. The second methodology, the Plan Integration for Resilience Scorecard™ (PIRS™) for Heat, focuses on plan policies that could influence urban heat hazards. We categorize policies by policy tool and heat mitigation strategy and score them based on their heat impact. Scored policies are then mapped to evaluate their spatial distribution and the net effect of the plan network. The resulting PIRS™ for Heat scorecard is compared with heat vulnerability indicators to assess policy alignment with risks. We find that both cities are proactively planning for heat resilience using similar plan and strategy types, however, there are clear and consistent opportunities for improvement. Combining these complementary plan evaluation methods provides a more comprehensive understanding of how plans address heat and a generalizable approach that communities everywhere could use to identify opportunities for improved heat resilience planning.
气候变化和城市高温造成的影响日益加剧，使社区更加迫切需要公平地制定防暑降温规划。西南沙漠地区的城市是美国最热和变暖速度最快的地区之一，因此它们处于防暑规划的最前沿。城市的抗热能力需要采用综合规划方法，在形成建筑环境和风险模式的规划网络中协调战略。迄今为止，很少有研究对城市供热规划的进展情况进行评估。本研究首次将两种新兴的规划评估方法结合起来，通过对亚利桑那州坦佩市和图森市的案例研究，考察规划网络如何塑造城市抗热能力。第一种方法是 "抗热规划质量评估"，它将现有的规划质量评估方法应用于抗热规划。我们对规划是否符合高质量规划的七项原则中的 56 项标准以及规划中包含的供热战略类型进行评估。第二种方法是 "抗热规划整合记分卡™"（PIRS™），重点关注可能影响城市热危害的规划政策。我们按照政策工具和热量缓解策略对政策进行分类，并根据其对热量的影响进行评分。然后对已评分的政策进行映射，以评估其空间分布和规划网络的净效应。得出的 PIRS™ for Heat 计分卡与热脆弱性指标进行比较，以评估政策与风险的一致性。我们发现，这两个城市都在使用类似的计划和战略类型积极规划抗热能力，但也存在明显且一致的改进机会。将这些互补的计划评估方法结合起来，可以更全面地了解计划如何解决高温问题，并提供一种可推广的方法，各地社区可利用这种方法确定改进抗高温规划的机会。
{"title":"Plan evaluation for heat resilience: complementary methods to comprehensively assess heat planning in Tempe and Tucson, Arizona","authors":"Sara Meerow, Ladd Keith, Malini Roy, Shaylynn Trego","doi":"10.1088/1748-9326/ad5d05","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5d05","url":null,"abstract":"Escalating impacts from climate change and urban heat are increasing the urgency for communities to equitably plan for heat resilience. Cities in the desert Southwest are among the hottest and fastest warming in the U.S., placing them on the front lines of heat planning. Urban heat resilience requires an integrated planning approach that coordinates strategies across the network of plans that shape the built environment and risk patterns. To date, few studies have assessed cities’ progress on heat planning. This research is the first to combine two emerging plan evaluation approaches to examine how networks of plans shape urban heat resilience through case studies of Tempe and Tucson, Arizona. The first methodology, Plan Quality Evaluation for Heat Resilience, adapts existing plan quality assessment approaches to heat. We assess whether plans meet 56 criteria across seven principles of high-quality planning and the types of heat strategies included in the plans. The second methodology, the Plan Integration for Resilience Scorecard™ (PIRS™) for Heat, focuses on plan policies that could influence urban heat hazards. We categorize policies by policy tool and heat mitigation strategy and score them based on their heat impact. Scored policies are then mapped to evaluate their spatial distribution and the net effect of the plan network. The resulting PIRS™ for Heat scorecard is compared with heat vulnerability indicators to assess policy alignment with risks. We find that both cities are proactively planning for heat resilience using similar plan and strategy types, however, there are clear and consistent opportunities for improvement. Combining these complementary plan evaluation methods provides a more comprehensive understanding of how plans address heat and a generalizable approach that communities everywhere could use to identify opportunities for improved heat resilience planning.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-30DOI: 10.1088/1748-9326/ad5d08
Linqing Yang, Asko Noormets
The phenological cycles of terrestrial ecosystems have shifted with the changing climate, and the altered timings of biogeochemical fluxes may also exert feedback on the climate system. As regulators of land carbon balance, relative shifts in photosynthetic and respiratory phenology under climate change are of great importance. However, the relative seasonal dynamics of these individual processes and their sensitivity to climate factors as well as the implications for carbon cycling are not well understood. In this study, we examined the relationship in the seasonality of gross primary production (GPP) and ecosystem respiration (RE) as well as their temperature sensitivities and the implications for carbon uptake with around 1500 site-years’ of data from FLUXNET 2015 and Boreal Ecosystem Productivity Simulator (BEPS) at 212 sites. The results showed that RE started earlier in the spring and ended later in the autumn than GPP over most biomes. Furthermore, the flux phenology metrics responded differently to temperature: GPP phenology was more sensitive to changes during the spring temperature than RE phenology, and less sensitive to autumn temperature than RE. We found large BEPS-observation discrepancies in seasonality metrics and their apparent temperature sensitivity. The site-based BEPS projections did not capture the observed seasonal metrics and temperature sensitivities in either GPP or RE seasonality metrics. Improved understanding of the asynchrony of GPP and RE as well as different sensitivity of environmental factors are of great significance for reliable future carbon balance projections.
陆地生态系统的物候周期随着气候的变化而变化，生物地球化学通量时间的改变也可能对气候系统产生反馈作用。作为陆地碳平衡的调节器，气候变化下光合作用和呼吸作用物候的相对变化非常重要。然而，人们对这些单个过程的相对季节动态及其对气候因素的敏感性以及对碳循环的影响还不甚了解。在这项研究中，我们利用 FLUXNET 2015 和北方生态系统生产力模拟器（BEPS）在 212 个地点的约 1500 个地点年的数据，研究了总初级生产量（GPP）和生态系统呼吸作用（RE）的季节性关系及其对温度的敏感性以及对碳吸收的影响。结果表明，在大多数生物群落中，RE 比 GPP 更早开始于春季，更晚结束于秋季。此外，通量物候指标对温度的反应也不同：与 RE 表观相比，GPP 表观对春季温度变化更为敏感，而对秋季温度的敏感性则低于 RE。我们发现，在季节性指标及其明显的温度敏感性方面，BEPS 与观测结果之间存在巨大差异。基于站点的 BEPS 预测并没有捕捉到观测到的 GPP 或 RE 季节性指标中的季节性指标和温度敏感性。更好地理解 GPP 和 RE 的非同步性以及环境因素的不同敏感性对于可靠的未来碳平衡预测具有重要意义。
{"title":"Asynchrony of the seasonal dynamics of gross primary production and ecosystem respiration","authors":"Linqing Yang, Asko Noormets","doi":"10.1088/1748-9326/ad5d08","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5d08","url":null,"abstract":"The phenological cycles of terrestrial ecosystems have shifted with the changing climate, and the altered timings of biogeochemical fluxes may also exert feedback on the climate system. As regulators of land carbon balance, relative shifts in photosynthetic and respiratory phenology under climate change are of great importance. However, the relative seasonal dynamics of these individual processes and their sensitivity to climate factors as well as the implications for carbon cycling are not well understood. In this study, we examined the relationship in the seasonality of gross primary production (GPP) and ecosystem respiration (RE) as well as their temperature sensitivities and the implications for carbon uptake with around 1500 site-years’ of data from FLUXNET 2015 and Boreal Ecosystem Productivity Simulator (BEPS) at 212 sites. The results showed that RE started earlier in the spring and ended later in the autumn than GPP over most biomes. Furthermore, the flux phenology metrics responded differently to temperature: GPP phenology was more sensitive to changes during the spring temperature than RE phenology, and less sensitive to autumn temperature than RE. We found large BEPS-observation discrepancies in seasonality metrics and their apparent temperature sensitivity. The site-based BEPS projections did not capture the observed seasonal metrics and temperature sensitivities in either GPP or RE seasonality metrics. Improved understanding of the asynchrony of GPP and RE as well as different sensitivity of environmental factors are of great significance for reliable future carbon balance projections.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-30DOI: 10.1088/1748-9326/ad60df
Ni Lu, Lin Zhang, Xiaolin Wang, Zehui Liu, Danyang Li, Jiayu Xu, Haiyue Tan, Mi Zhou, Daven K Henze
While China’s clean air actions implemented since 2013 have been effective in mitigating PM2.5 air pollution, the large emission reductions during the COVID-19 lockdown period in early 2020 did not similarly alleviate PM2.5 pollution in North China, reflecting a distinct nonlinear chemical response of PM2.5 formation to emission changes. Here we apply emission-concentration relationships for PM2.5 diagnosed using the adjoint approach to quantitatively assess how chemical nonlinearity affects PM2.5 over Beijing in February 2020 in response to two emission reduction scenarios: the COVID-19 lockdown and 2013–2017 emission controls. We find that, in the absence of chemical nonlinearity, the COVID-19 lockdown would decrease PM2.5 in Beijing by 17.9 μg m–3, and the 2013–2017 emission controls resulted in a larger decrease of 54.2 μg m–3 because of greater reductions of SO2 and primary aerosol emissions. Chemical nonlinearity offset the decrease for Beijing PM2.5 by 3.4 μg m–3 during the lockdown due to enhanced sensitivity of aerosol nitrate to NOx emissions, but enhanced the efficiency of 2013–2017 emission controls by 11.9 μg m–3 due to the weakened heterogeneous reaction of sulfate. Such nonlinear chemical effects are important to estimate and consider when designing or assessing air pollution control strategies.
{"title":"Assessing the nonlinearity of wintertime PM2.5 formation in response to precursor emission changes in North China with the adjoint method","authors":"Ni Lu, Lin Zhang, Xiaolin Wang, Zehui Liu, Danyang Li, Jiayu Xu, Haiyue Tan, Mi Zhou, Daven K Henze","doi":"10.1088/1748-9326/ad60df","DOIUrl":"https://doi.org/10.1088/1748-9326/ad60df","url":null,"abstract":"While China’s clean air actions implemented since 2013 have been effective in mitigating PM<sub>2.5</sub> air pollution, the large emission reductions during the COVID-19 lockdown period in early 2020 did not similarly alleviate PM<sub>2.5</sub> pollution in North China, reflecting a distinct nonlinear chemical response of PM<sub>2.5</sub> formation to emission changes. Here we apply emission-concentration relationships for PM<sub>2.5</sub> diagnosed using the adjoint approach to quantitatively assess how chemical nonlinearity affects PM<sub>2.5</sub> over Beijing in February 2020 in response to two emission reduction scenarios: the COVID-19 lockdown and 2013–2017 emission controls. We find that, in the absence of chemical nonlinearity, the COVID-19 lockdown would decrease PM<sub>2.5</sub> in Beijing by 17.9 <italic toggle=\"yes\">μ</italic>g m<sup>–3</sup>, and the 2013–2017 emission controls resulted in a larger decrease of 54.2 <italic toggle=\"yes\">μ</italic>g m<sup>–3</sup> because of greater reductions of SO<sub>2</sub> and primary aerosol emissions. Chemical nonlinearity offset the decrease for Beijing PM<sub>2.5</sub> by 3.4 <italic toggle=\"yes\">μ</italic>g m<sup>–3</sup> during the lockdown due to enhanced sensitivity of aerosol nitrate to NO<italic toggle=\"yes\"><sub>x</sub></italic> emissions, but enhanced the efficiency of 2013–2017 emission controls by 11.9 <italic toggle=\"yes\">μ</italic>g m<sup>–3</sup> due to the weakened heterogeneous reaction of sulfate. Such nonlinear chemical effects are important to estimate and consider when designing or assessing air pollution control strategies.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-25DOI: 10.1088/1748-9326/ad64e9
Wendi Qu, Guangxuan Han, Josep Penuelas, Xiaoyue Wang and Baohua Xie
Coastal wetlands remarkably influence terrestrial carbon (C) stock by serving as natural reservoirs for ‘blue carbon’. Anthropogenic nitrogen (N) enrichment shapes the dynamics of soil and plant communities, consequently affecting the C balance and ecosystem functions. The impacts of various levels of N enrichment on CO2 sequestration in coastal wetlands, however, remain elusive. Here we conducted a long-term field study of N fertilization in a coastal wetland in the Yellow River Delta, China, to investigate N effects on soil properties, indicators of plant dynamics, and fluxes of ecosystem CO2. The results indicated that moderate N enrichment (5 g N m−2 y−1) stimulated C fluxes with increases in gross primary productivity (+26.4%), ecosystem respiration (+23.3%), and net ecosystem exchange (NEE, +31.5%) relative to the control. High (10 g N m−2 y−1) and extreme (20 g N m−2 y−1) amounts of N enrichment, however, had relatively minor impacts on these CO2 fluxes. Overall, we observed a decrease in soil electrical conductivity (−24.6%) and increases in soil organic C (+25.2%) and microbial biomass C (+369.3%) for N enrichment. N enrichment also altered the composition of plant species, with a higher proportion of a local dominant species (Phragmites australis), and affected root biomass distribution, with more biomass near the soil surface. Structural equation modeling explained 65.2% of the variance of NEE and supported the assumption that N enrichment could alter the dynamics of soil properties and plant conditions and accelerate ecosystem CO2 sequestration. These findings have important implications for forecasting the C cycle with increasing N deposition in coastal wetlands, contributing to the projections of the global C budget.
沿海湿地是天然的 "蓝碳库"，对陆地碳（C）存量有着显著影响。人为的氮（N）富集会影响土壤和植物群落的动态，从而影响碳平衡和生态系统功能。然而，不同程度的氮富集对沿海湿地二氧化碳封存的影响仍然难以捉摸。在此，我们对中国黄河三角洲的滨海湿地进行了长期的氮肥施用实地研究，探讨氮肥对土壤性质、植物动态指标和生态系统二氧化碳通量的影响。结果表明，与对照组相比，中等氮肥浓度（5 g N m-2 y-1）刺激了碳通量，总初级生产力（+26.4%）、生态系统呼吸作用（+23.3%）和生态系统净交换量（NEE，+31.5%）均有所增加。然而，高浓度（10 g N m-2 y-1）和极高浓度（20 g N m-2 y-1）的氮对这些二氧化碳通量的影响相对较小。总体而言，我们观察到土壤电导率下降（-24.6%），土壤有机碳（+25.2%）和微生物生物量碳（+369.3%）增加。氮富集还改变了植物物种的组成，当地优势物种（Phragmites australis）的比例增加，并影响了根部生物量的分布，土壤表面附近的生物量增加。结构方程模型解释了 65.2% 的 NEE 方差，支持了氮富集可改变土壤性质和植物状况的动态变化并加速生态系统二氧化碳固存的假设。这些发现对预测沿海湿地氮沉积增加时的碳循环具有重要意义，有助于预测全球碳预算。
{"title":"Moderate nitrogen enrichment increases CO2 sink strength in a coastal wetland","authors":"Wendi Qu, Guangxuan Han, Josep Penuelas, Xiaoyue Wang and Baohua Xie","doi":"10.1088/1748-9326/ad64e9","DOIUrl":"https://doi.org/10.1088/1748-9326/ad64e9","url":null,"abstract":"Coastal wetlands remarkably influence terrestrial carbon (C) stock by serving as natural reservoirs for ‘blue carbon’. Anthropogenic nitrogen (N) enrichment shapes the dynamics of soil and plant communities, consequently affecting the C balance and ecosystem functions. The impacts of various levels of N enrichment on CO2 sequestration in coastal wetlands, however, remain elusive. Here we conducted a long-term field study of N fertilization in a coastal wetland in the Yellow River Delta, China, to investigate N effects on soil properties, indicators of plant dynamics, and fluxes of ecosystem CO2. The results indicated that moderate N enrichment (5 g N m−2 y−1) stimulated C fluxes with increases in gross primary productivity (+26.4%), ecosystem respiration (+23.3%), and net ecosystem exchange (NEE, +31.5%) relative to the control. High (10 g N m−2 y−1) and extreme (20 g N m−2 y−1) amounts of N enrichment, however, had relatively minor impacts on these CO2 fluxes. Overall, we observed a decrease in soil electrical conductivity (−24.6%) and increases in soil organic C (+25.2%) and microbial biomass C (+369.3%) for N enrichment. N enrichment also altered the composition of plant species, with a higher proportion of a local dominant species (Phragmites australis), and affected root biomass distribution, with more biomass near the soil surface. Structural equation modeling explained 65.2% of the variance of NEE and supported the assumption that N enrichment could alter the dynamics of soil properties and plant conditions and accelerate ecosystem CO2 sequestration. These findings have important implications for forecasting the C cycle with increasing N deposition in coastal wetlands, contributing to the projections of the global C budget.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141782369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-18DOI: 10.1088/1748-9326/ad5ab2
Yara Shennan-Farpón, Aline C Soterroni, Marluce Scarabello and Piero Visconti
Brazil’s Atlantic Forest is a global restoration hotspot. Most of the remaining forest areas are degraded and separated by large cities, and agricultural lands essential for national food security. Brazil’s restoration agenda is defined by multiple national and global restoration targets and policies, including Brazil’s Native Vegetation Protection Law (No. 12,651/2012) also known as the Forest Code, which sets minimum levels of native vegetation to be maintained or restored in rural properties. In this study we simulate the impacts of alternative restoration policies addressing targets for Brazil, and explore their impacts on selected terrestrial species and agricultural development potential in the Atlantic Forest biome. Our results show several policy options could result in different restoration amounts and spatial distributions being implemented between 2020 and 2050, but trade-offs between agriculture, biodiversity and rural livelihoods differ. Compared to the baseline scenario (implementation of the Forest Code), a scenario which focuses restoration on small farms (not mandated to undergo restoration under the current legislation) could increase forest area by 6.7 Mha across the biome (139% more than with the Forest Code), while a scenario which maximizes biodiversity gains could lead to an additional 3.9 Mha by 2050 (81% more compared to the Forest Code). We find that our restoration scenarios still allow cropland expansion and an increase in cattle herd, while pasturelands decrease. There are relatively small agricultural production losses under the alternative restoration scenarios when compared to the baseline (up to 14.4%), meaning that cattle ranching intensification is critical to enable large-scale restoration to co-exist with agricultural production. Our scenarios suggest that ambitious restoration targets in the Atlantic Forest biome (up to 15.5 Mha, consistent with existing regional initiatives) could be feasible with necessary improvements in pasture yield and a focus on scaling up support and developing restoration policies for smallholder farmers.
{"title":"Using policy scenarios to assess challenges and opportunities for reaching restoration targets in Brazil’s Atlantic Forest","authors":"Yara Shennan-Farpón, Aline C Soterroni, Marluce Scarabello and Piero Visconti","doi":"10.1088/1748-9326/ad5ab2","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5ab2","url":null,"abstract":"Brazil’s Atlantic Forest is a global restoration hotspot. Most of the remaining forest areas are degraded and separated by large cities, and agricultural lands essential for national food security. Brazil’s restoration agenda is defined by multiple national and global restoration targets and policies, including Brazil’s Native Vegetation Protection Law (No. 12,651/2012) also known as the Forest Code, which sets minimum levels of native vegetation to be maintained or restored in rural properties. In this study we simulate the impacts of alternative restoration policies addressing targets for Brazil, and explore their impacts on selected terrestrial species and agricultural development potential in the Atlantic Forest biome. Our results show several policy options could result in different restoration amounts and spatial distributions being implemented between 2020 and 2050, but trade-offs between agriculture, biodiversity and rural livelihoods differ. Compared to the baseline scenario (implementation of the Forest Code), a scenario which focuses restoration on small farms (not mandated to undergo restoration under the current legislation) could increase forest area by 6.7 Mha across the biome (139% more than with the Forest Code), while a scenario which maximizes biodiversity gains could lead to an additional 3.9 Mha by 2050 (81% more compared to the Forest Code). We find that our restoration scenarios still allow cropland expansion and an increase in cattle herd, while pasturelands decrease. There are relatively small agricultural production losses under the alternative restoration scenarios when compared to the baseline (up to 14.4%), meaning that cattle ranching intensification is critical to enable large-scale restoration to co-exist with agricultural production. Our scenarios suggest that ambitious restoration targets in the Atlantic Forest biome (up to 15.5 Mha, consistent with existing regional initiatives) could be feasible with necessary improvements in pasture yield and a focus on scaling up support and developing restoration policies for smallholder farmers.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141746196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-18DOI: 10.1088/1748-9326/ad6017
Taylor Y Wilmot, John C Lin, Dien Wu, Tomohiro Oda and Eric A Kort
Over the past decade, 1000s of cities have pledged reductions in carbon dioxide emissions. However, tracking progress toward these pledges has largely relied exclusively on activity-based, self-reported emissions inventories, which often underestimate emissions due to incomplete accounting. Furthermore, the lack of a consistent framework that may be deployed broadly, across political boundaries, hampers understanding of changes in both city-scale emissions and the global summation of urban emissions mitigation actions, with insight being particularly limited for cities within the global south. Given the pressing need for rapid decarbonization, development of a consistent framework that tracks progress toward city-scale emissions reduction targets, while providing actionable information for policy makers, will be critical. Here, we combine satellite-based observations of atmospheric carbon dioxide and an atmospheric model to present an atmospherically-based framework for monitoring changes in urban emissions and related intensity metrics. Application of this framework to 77 cities captures ∼16% of global carbon dioxide emissions, similar in magnitude to the total direct emissions of the United States or Europe, and demonstrates the framework’s ability to track changes in emissions via satellite-observation. COVID-19 lockdowns correspond to an average ∼21% reduction in emissions across urban systems over March–May of 2020 relative to non-lockdown years. Urban scaling analyses suggest that per capita energy savings drive decreases in emissions per capita as population density increases, while local affluence and economic development correspond to increasing emissions. Results highlight the potential for a global atmospherically-based monitoring framework to complement activity-based inventories and provide actionable information regarding interactions between city-scale emissions and local policy actions.
{"title":"Toward a satellite-based monitoring system for urban CO2 emissions in support of global collective climate mitigation actions","authors":"Taylor Y Wilmot, John C Lin, Dien Wu, Tomohiro Oda and Eric A Kort","doi":"10.1088/1748-9326/ad6017","DOIUrl":"https://doi.org/10.1088/1748-9326/ad6017","url":null,"abstract":"Over the past decade, 1000s of cities have pledged reductions in carbon dioxide emissions. However, tracking progress toward these pledges has largely relied exclusively on activity-based, self-reported emissions inventories, which often underestimate emissions due to incomplete accounting. Furthermore, the lack of a consistent framework that may be deployed broadly, across political boundaries, hampers understanding of changes in both city-scale emissions and the global summation of urban emissions mitigation actions, with insight being particularly limited for cities within the global south. Given the pressing need for rapid decarbonization, development of a consistent framework that tracks progress toward city-scale emissions reduction targets, while providing actionable information for policy makers, will be critical. Here, we combine satellite-based observations of atmospheric carbon dioxide and an atmospheric model to present an atmospherically-based framework for monitoring changes in urban emissions and related intensity metrics. Application of this framework to 77 cities captures ∼16% of global carbon dioxide emissions, similar in magnitude to the total direct emissions of the United States or Europe, and demonstrates the framework’s ability to track changes in emissions via satellite-observation. COVID-19 lockdowns correspond to an average ∼21% reduction in emissions across urban systems over March–May of 2020 relative to non-lockdown years. Urban scaling analyses suggest that per capita energy savings drive decreases in emissions per capita as population density increases, while local affluence and economic development correspond to increasing emissions. Results highlight the potential for a global atmospherically-based monitoring framework to complement activity-based inventories and provide actionable information regarding interactions between city-scale emissions and local policy actions.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141744362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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