Pub Date : 2024-07-04DOI: 10.1088/1748-9326/ad5b75
Minghui Hu, Yiren Zhu, Jianling Li, Xianyu Yao, Yuanliu Hu, Xiaolin Huang, Yonghui Li, Deqiang Zhang and Qi Deng
Due to increasing anthropogenic pressure, over half of the world’s tropical forests are reforested or afforested secondary forests or plantations. The recovery pace and potential of these forests depend largely on soil microbially-mediated biogeochemical cycling. Here we measured soil extracellular enzyme activities and quantified microbial metabolic limitations using a vector analysis in a bare land (BL, representing the original state before restoration), two afforested sites [i.e. a restored secondary forest (MF) and a managed Eucalyptus exserta plantation (EP)] and a nearby undisturbed forest (UF) in south China. Results showed that soil microbial metabolisms were co-limited by carbon (C) and phosphorus (P) across the four forests. Both microbial C and P limitations were higher in BL than UF. Microbial C limitation significantly reduced after restoration only in MF when compared to BL, but it was still higher than that in UF. Interestingly, microbial P limitation significantly enhanced after restoration in both EP and MF when compared to BL, and it did not differ between the two restored forests. Structural equation modeling (SEM) showed that microbial C limitation was primarily attributed to microbial C use efficiency, while microbial P limitation was co-driven by plant biomass, microbial C use efficiency and soil P availability. These findings suggest microbial C limitation could be gradually recovered after forest restoration in southern China, which would facilitate soil organic carbon accumulation. However, the enhanced microbial P limitation after forest restoration underlines the necessity to develop optimal P management in these restored forests.
由于人为压力不断增加,世界上一半以上的热带森林都是重新造林或植树造林的次生林或人工林。这些森林的恢复速度和潜力在很大程度上取决于土壤微生物介导的生物地球化学循环。在这里,我们采用矢量分析法测量了中国南部的一片裸地(BL,代表恢复前的原始状态)、两片造林地(即一片恢复的次生林(MF)和一片人工管理的桉树种植园(EP))以及附近一片未受干扰的森林(UF)的土壤胞外酶活性并量化了微生物代谢限制。结果表明,四片森林的土壤微生物代谢受到碳(C)和磷(P)的共同限制。BL的微生物碳限制和磷限制均高于UF。与 BL 相比,只有 MF 的微生物 C 限制在恢复后明显减少,但仍高于 UF。有趣的是,与 BL 相比,EP 和 MF 的微生物 P 限制在恢复后明显增加,且在两种恢复的森林之间没有差异。结构方程建模(SEM)表明,微生物碳限制主要归因于微生物的碳利用效率,而微生物磷限制则由植物生物量、微生物碳利用效率和土壤磷供应量共同驱动。这些研究结果表明,中国南方森林恢复后,微生物 C 限制可逐渐恢复,这将促进土壤有机碳的积累。然而,森林恢复后微生物对磷的限制增强,这凸显了在这些恢复后的森林中开展最佳磷管理的必要性。
{"title":"Changes in soil microbial metabolic limitations after half-century forest restoration in degraded tropical lands","authors":"Minghui Hu, Yiren Zhu, Jianling Li, Xianyu Yao, Yuanliu Hu, Xiaolin Huang, Yonghui Li, Deqiang Zhang and Qi Deng","doi":"10.1088/1748-9326/ad5b75","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5b75","url":null,"abstract":"Due to increasing anthropogenic pressure, over half of the world’s tropical forests are reforested or afforested secondary forests or plantations. The recovery pace and potential of these forests depend largely on soil microbially-mediated biogeochemical cycling. Here we measured soil extracellular enzyme activities and quantified microbial metabolic limitations using a vector analysis in a bare land (BL, representing the original state before restoration), two afforested sites [i.e. a restored secondary forest (MF) and a managed Eucalyptus exserta plantation (EP)] and a nearby undisturbed forest (UF) in south China. Results showed that soil microbial metabolisms were co-limited by carbon (C) and phosphorus (P) across the four forests. Both microbial C and P limitations were higher in BL than UF. Microbial C limitation significantly reduced after restoration only in MF when compared to BL, but it was still higher than that in UF. Interestingly, microbial P limitation significantly enhanced after restoration in both EP and MF when compared to BL, and it did not differ between the two restored forests. Structural equation modeling (SEM) showed that microbial C limitation was primarily attributed to microbial C use efficiency, while microbial P limitation was co-driven by plant biomass, microbial C use efficiency and soil P availability. These findings suggest microbial C limitation could be gradually recovered after forest restoration in southern China, which would facilitate soil organic carbon accumulation. However, the enhanced microbial P limitation after forest restoration underlines the necessity to develop optimal P management in these restored forests.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547768","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 : 2024-07-04DOI: 10.1088/1748-9326/ad5a24
Adelaide Baronchelli, Elena Vallino, Silvana Dalmazzone, Luca Ridolfi and Francesco Laio
The paper investigates the influence of major food corporations on global rice and coffee markets from 2013 to 2022, with a focus on market presence and water usage. It uses detailed data from the Euromonitor Passport and the CWASI datasets to analyze environmental impacts and virtual water (VW) flows at the company level, addressing gaps in the existing literature. Key findings show that although rice sales are larger than those of coffee in quantity, coffee embeds a higher total water use due to its greater unit water footprint (WF). The rice market is less internationalized and concentrated compared to the coffee market, where a few companies hold significant market shares across multiple countries. In 2022, the top 12 rice-selling companies control 16% of the global rice WF, exceeding the combined WF of the top three rice-importing nations. Similarly, the top 15 coffee-selling companies command 55% of the global roasted coffee WF, with significant disparities in VW quantities compared to major importing nations. The coffee market exhibits a higher number of companies with larger shares of WF than volumes, with this disparity increasing over time. Furthermore, more countries exhibit high and moderate concentration indices for coffee sales compared to rice. These findings highlight the considerable concentration of water resources among large companies, particularly in the coffee sector. The paper emphasizes the importance of considering the environmental implications of corporate activities in food supply chains, providing valuable insights for sustainability efforts in the agri-food industry.
{"title":"Large agri-food corporations in the global staple and cash crops markets: a quantitative analysis of rice and coffee through the virtual water perspective","authors":"Adelaide Baronchelli, Elena Vallino, Silvana Dalmazzone, Luca Ridolfi and Francesco Laio","doi":"10.1088/1748-9326/ad5a24","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5a24","url":null,"abstract":"The paper investigates the influence of major food corporations on global rice and coffee markets from 2013 to 2022, with a focus on market presence and water usage. It uses detailed data from the Euromonitor Passport and the CWASI datasets to analyze environmental impacts and virtual water (VW) flows at the company level, addressing gaps in the existing literature. Key findings show that although rice sales are larger than those of coffee in quantity, coffee embeds a higher total water use due to its greater unit water footprint (WF). The rice market is less internationalized and concentrated compared to the coffee market, where a few companies hold significant market shares across multiple countries. In 2022, the top 12 rice-selling companies control 16% of the global rice WF, exceeding the combined WF of the top three rice-importing nations. Similarly, the top 15 coffee-selling companies command 55% of the global roasted coffee WF, with significant disparities in VW quantities compared to major importing nations. The coffee market exhibits a higher number of companies with larger shares of WF than volumes, with this disparity increasing over time. Furthermore, more countries exhibit high and moderate concentration indices for coffee sales compared to rice. These findings highlight the considerable concentration of water resources among large companies, particularly in the coffee sector. The paper emphasizes the importance of considering the environmental implications of corporate activities in food supply chains, providing valuable insights for sustainability efforts in the agri-food industry.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547770","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 : 2024-07-04DOI: 10.1088/1748-9326/ad5a26
Adam Lampert
Although climate change is expected to cause significant negative impacts, climate treaties give hope for reducing greenhouse gas (GHG) emissions, potentially leading to less severe climate change. However, climate change is a public bad: If each country aims to maximize its own benefit, some countries might free ride and continue to emit GHGs. Consequently, climate treaties have seen limited success, and a central question is how future treaties can achieve GHG emission reduction and also be ‘self-enforcing’—where participating countries have no incentive to withdraw or modify their contributions. Here we examine a dynamic negotiation process involving multiple countries, each deciding whether and when to join the agreement and whether to penalize non-participants. In particular, we distinguish between (1) indirect punishment, in which countries invest less in emission reduction in response to non-compliance of other countries, and (2) direct punishment, in which countries impose sanctions, such as punitive tariffs, against countries that do not comply. We analyze the negotiation process using evolutionary game theory. We show that how the two types of punishment are implemented greatly affects the agreement’s outcome. In particular, an efficient combination of the punishments could lead to more desirable self-enforcing agreements. These findings indicate that integrating punitive measures with an effective negotiation framework could result in more desirable climate agreements.
{"title":"Rethinking climate agreements: self-enforcing strategies for emission reduction through sanctions","authors":"Adam Lampert","doi":"10.1088/1748-9326/ad5a26","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5a26","url":null,"abstract":"Although climate change is expected to cause significant negative impacts, climate treaties give hope for reducing greenhouse gas (GHG) emissions, potentially leading to less severe climate change. However, climate change is a public bad: If each country aims to maximize its own benefit, some countries might free ride and continue to emit GHGs. Consequently, climate treaties have seen limited success, and a central question is how future treaties can achieve GHG emission reduction and also be ‘self-enforcing’—where participating countries have no incentive to withdraw or modify their contributions. Here we examine a dynamic negotiation process involving multiple countries, each deciding whether and when to join the agreement and whether to penalize non-participants. In particular, we distinguish between (1) indirect punishment, in which countries invest less in emission reduction in response to non-compliance of other countries, and (2) direct punishment, in which countries impose sanctions, such as punitive tariffs, against countries that do not comply. We analyze the negotiation process using evolutionary game theory. We show that how the two types of punishment are implemented greatly affects the agreement’s outcome. In particular, an efficient combination of the punishments could lead to more desirable self-enforcing agreements. These findings indicate that integrating punitive measures with an effective negotiation framework could result in more desirable climate agreements.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141552610","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 : 2024-07-04DOI: 10.1088/1748-9326/ad5b08
Xinyi Cao, Chao Li, Yuwei Hu, Yulong Yao and Juan Li
Marine heatwaves (MHWs) have become longer and more frequent over the past century under anthropogenic climate change, with devastating impacts on marine ecosystems. Surface MHWs (SMHWs) and their drivers have been extensively studied using satellite sea surface temperature data, yet the mechanism and characteristics of subsurface MHWs, especially bottom MHWs (BMHWs) along continental shelves, remain unclear. Based on a high-resolution ocean reanalysis dataset, we compare SMHWs and BMHWs along the continental shelf of China and find that BMHWs are typically longer (0–16 d) and more intense (0 °C–50 °C days) than SMHWs. The categorizing of both the BMHW and SMHW shows that moderate and strong events commonly occur in most areas with relatively large spatial coverage, whereas severe and extreme events occur with relatively small spatial coverage. There is a clear negative relationship between the BMHW intensity and ocean depth along the continental shelf, while the BMHW annual days and ocean depth are positively correlated in the Bohai and East China Seas. Generally, BMHWs and SMHWs occur more frequently in shallow coastal regions where the mixed layer depth is more likely to extend to the seafloor, resulting in high BMHW and SMHW synchrony. In addition to spatial coherence, there is a good temporal correspondence between BMHWs and SMHWs across the continental shelf of China from 1993 to 2020.
{"title":"Understanding bottom and surface marine heatwaves along the continental shelf of China","authors":"Xinyi Cao, Chao Li, Yuwei Hu, Yulong Yao and Juan Li","doi":"10.1088/1748-9326/ad5b08","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5b08","url":null,"abstract":"Marine heatwaves (MHWs) have become longer and more frequent over the past century under anthropogenic climate change, with devastating impacts on marine ecosystems. Surface MHWs (SMHWs) and their drivers have been extensively studied using satellite sea surface temperature data, yet the mechanism and characteristics of subsurface MHWs, especially bottom MHWs (BMHWs) along continental shelves, remain unclear. Based on a high-resolution ocean reanalysis dataset, we compare SMHWs and BMHWs along the continental shelf of China and find that BMHWs are typically longer (0–16 d) and more intense (0 °C–50 °C days) than SMHWs. The categorizing of both the BMHW and SMHW shows that moderate and strong events commonly occur in most areas with relatively large spatial coverage, whereas severe and extreme events occur with relatively small spatial coverage. There is a clear negative relationship between the BMHW intensity and ocean depth along the continental shelf, while the BMHW annual days and ocean depth are positively correlated in the Bohai and East China Seas. Generally, BMHWs and SMHWs occur more frequently in shallow coastal regions where the mixed layer depth is more likely to extend to the seafloor, resulting in high BMHW and SMHW synchrony. In addition to spatial coherence, there is a good temporal correspondence between BMHWs and SMHWs across the continental shelf of China from 1993 to 2020.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547745","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 : 2024-07-04DOI: 10.1088/1748-9326/ad5b05
Nan Lei, Yongkun Xie, Zhongrui Bao, Min Zhao, Zifan Su and Xiaodan Guan
Heatwaves have been more common in China in recent years, largely attributed to human-caused global warming. While ocean variability, notably El Niño–Southern Oscillation (ENSO), influences regional heatwave fluctuations in China, the impact of other oceanic variability remains unclear. Here we show that the tropical Indian Ocean (TIO) and the tropical and subtropical North Atlantic Ocean (TSNAO) significantly modulate the decadal heatwave fluctuations in China. Among them, TIO has the most significant impact on northern China, while TSNAO has a greater impact on eastern China. TIO and TSNAO remotely influence heatwaves in China through abnormal sea surface temperatures (SSTs)-induced changes in atmospheric circulations involving westerlies and Rossby wave trains. Moreover, we demonstrated the physical processes responsible for heatwave fluctuations caused by TIO and TSNAO variability. The heatwave changes were determined jointly by vertical motion-related adiabatic and energy input-related diabatic temperature modifications. Our findings show that, in addition to ENSO, variability in the Indian and Atlantic Oceans is critical for understanding and predicting decadal heatwave changes in China.
{"title":"Decadal heatwave fluctuations in China caused by the Indian and Atlantic Oceans","authors":"Nan Lei, Yongkun Xie, Zhongrui Bao, Min Zhao, Zifan Su and Xiaodan Guan","doi":"10.1088/1748-9326/ad5b05","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5b05","url":null,"abstract":"Heatwaves have been more common in China in recent years, largely attributed to human-caused global warming. While ocean variability, notably El Niño–Southern Oscillation (ENSO), influences regional heatwave fluctuations in China, the impact of other oceanic variability remains unclear. Here we show that the tropical Indian Ocean (TIO) and the tropical and subtropical North Atlantic Ocean (TSNAO) significantly modulate the decadal heatwave fluctuations in China. Among them, TIO has the most significant impact on northern China, while TSNAO has a greater impact on eastern China. TIO and TSNAO remotely influence heatwaves in China through abnormal sea surface temperatures (SSTs)-induced changes in atmospheric circulations involving westerlies and Rossby wave trains. Moreover, we demonstrated the physical processes responsible for heatwave fluctuations caused by TIO and TSNAO variability. The heatwave changes were determined jointly by vertical motion-related adiabatic and energy input-related diabatic temperature modifications. Our findings show that, in addition to ENSO, variability in the Indian and Atlantic Oceans is critical for understanding and predicting decadal heatwave changes in China.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141552611","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 : 2024-07-04DOI: 10.1088/1748-9326/ad5bf1
Lorenzo Rinaldi, Debora Ghezzi, Emanuela Colombo and Matteo Vincenzo Rocco
As a key material for manufacturing clean energy technologies, steel is crucial for energy transition, but its production causes 2.6 Gton of CO2 emissions at global level each year. In 2020 the European Union (EU) set a net-zero emissions target by 2050, fostering innovation in the steel industry to reduce its environmental impact. However, a scenario-oriented and technologically comprehensive analysis assessing prospected environmental and market implications of steel decarbonisation strategies remains a gap, which is addressed in this paper. The analysis adopts a hybrid input-output-based life-cycle assessment model built in the MARIO framework, extending the Exiobase database to represent the supply chains of the most promising low-carbon steelmaking technologies in the EU, such as hydrogen- or charcoal-injected blast furnaces and natural gas- and hydrogen-based direct reduction routes. The penetration of these technologies is explored by formulating scenarios resembling European climate targets. The results show a reduction in the carbon footprint of steel across all scenarios, ranging up to −26% in 2030 and to −60% in 2050. However, the extent of footprint reduction is highly dependent on the share of clean electricity in the European supply mix, highlighting the relevance of holistic decarbonisation strategies. Economic implications affect steel prices, which rise up to 25% in 2030 and 56% in 2050, opening discussions on the need for suitable policies such as CBAM to avoid protectionism and encourage international technological progress.
{"title":"Assessing environmental and market implications of steel decarbonisation strategies: a hybrid input-output model for the European union","authors":"Lorenzo Rinaldi, Debora Ghezzi, Emanuela Colombo and Matteo Vincenzo Rocco","doi":"10.1088/1748-9326/ad5bf1","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5bf1","url":null,"abstract":"As a key material for manufacturing clean energy technologies, steel is crucial for energy transition, but its production causes 2.6 Gton of CO2 emissions at global level each year. In 2020 the European Union (EU) set a net-zero emissions target by 2050, fostering innovation in the steel industry to reduce its environmental impact. However, a scenario-oriented and technologically comprehensive analysis assessing prospected environmental and market implications of steel decarbonisation strategies remains a gap, which is addressed in this paper. The analysis adopts a hybrid input-output-based life-cycle assessment model built in the MARIO framework, extending the Exiobase database to represent the supply chains of the most promising low-carbon steelmaking technologies in the EU, such as hydrogen- or charcoal-injected blast furnaces and natural gas- and hydrogen-based direct reduction routes. The penetration of these technologies is explored by formulating scenarios resembling European climate targets. The results show a reduction in the carbon footprint of steel across all scenarios, ranging up to −26% in 2030 and to −60% in 2050. However, the extent of footprint reduction is highly dependent on the share of clean electricity in the European supply mix, highlighting the relevance of holistic decarbonisation strategies. Economic implications affect steel prices, which rise up to 25% in 2030 and 56% in 2050, opening discussions on the need for suitable policies such as CBAM to avoid protectionism and encourage international technological progress.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141552771","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 : 2024-07-04DOI: 10.1088/1748-9326/ad5b0a
Zitong Shi and Gensuo Jia
With rising occurrence of heatwaves and ongoing urban expansion, urban residents are facing severer heat-related stress under the combined effects of urban heat island (UHI) and heatwaves. Controversial results, however, have been reported regarding whether the UHI is exacerbated during heatwaves. In this study, we used fused ground and satellite daily maximum air temperature data to evaluate the variation of UHI intensities under heatwaves across 225 major cities in mainland China during 2003–2020. Overall, urban areas showed an enhanced UHI intensity of up to 0.94 °C during heatwaves, nearly double compared to normal periods. The interaction between UHIs and heatwaves was sensitive to local background precipitation. Under the similar urbanization and vegetation greenness, the amplified warming in urban areas during heatwaves was more pronounced in wet climates. In megapolitan regions characterized by continuous urban development, the UHI intensified much stronger during heatwaves due to the heat accumulation within urbanized areas and the advection of heat from neighboring cities. Our results contribute to understanding the interactions between UHIs and heatwaves which may strongly increase heat risk in cities. Further work on the variations of this interaction under future warming and consequent impacts on human health and energy use is needed.
{"title":"Changes in urban heat island intensity during heatwaves in China","authors":"Zitong Shi and Gensuo Jia","doi":"10.1088/1748-9326/ad5b0a","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5b0a","url":null,"abstract":"With rising occurrence of heatwaves and ongoing urban expansion, urban residents are facing severer heat-related stress under the combined effects of urban heat island (UHI) and heatwaves. Controversial results, however, have been reported regarding whether the UHI is exacerbated during heatwaves. In this study, we used fused ground and satellite daily maximum air temperature data to evaluate the variation of UHI intensities under heatwaves across 225 major cities in mainland China during 2003–2020. Overall, urban areas showed an enhanced UHI intensity of up to 0.94 °C during heatwaves, nearly double compared to normal periods. The interaction between UHIs and heatwaves was sensitive to local background precipitation. Under the similar urbanization and vegetation greenness, the amplified warming in urban areas during heatwaves was more pronounced in wet climates. In megapolitan regions characterized by continuous urban development, the UHI intensified much stronger during heatwaves due to the heat accumulation within urbanized areas and the advection of heat from neighboring cities. Our results contribute to understanding the interactions between UHIs and heatwaves which may strongly increase heat risk in cities. Further work on the variations of this interaction under future warming and consequent impacts on human health and energy use is needed.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547746","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 : 2024-07-04DOI: 10.1088/1748-9326/ad5a28
Will W Qiang, Chen Luo, Shuai Shi, Huaiqian Lyu, Tianzuo Wen, Steve H L Yim and Harry F Lee
This research employs China’s steel restriction policy as a backdrop to investigate environmental policies’ unintended and counterproductive effects. Using high-resolution satellite-derived data and panel Difference-in-Differences regression, we found that the air pollution concentration in cities implementing the steel restriction policy is 5.688 μg/m3 higher than in control group cities. Additionally, the growth rate of air pollution in these cities is 6.577% faster. This quantitative evidence substantiates the backfire effect of the anticipation of environmental policy, where the delay between a policy’s announcement and its enforcement leads to a short-term surge in pollution levels. For China and other emerging economies, the development of a thorough and deliberate intergovernmental cooperation strategy is critical when formulating environmental policies. It involves synchronizing the efforts of different government levels in applying pollution controls and diminishing the interval of potential intense pollution in the pre-implementation phase.
{"title":"Pollution acceleration before braking: Evidence of environmental deterioration from the anticipated steel restriction policy in China","authors":"Will W Qiang, Chen Luo, Shuai Shi, Huaiqian Lyu, Tianzuo Wen, Steve H L Yim and Harry F Lee","doi":"10.1088/1748-9326/ad5a28","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5a28","url":null,"abstract":"This research employs China’s steel restriction policy as a backdrop to investigate environmental policies’ unintended and counterproductive effects. Using high-resolution satellite-derived data and panel Difference-in-Differences regression, we found that the air pollution concentration in cities implementing the steel restriction policy is 5.688 μg/m3 higher than in control group cities. Additionally, the growth rate of air pollution in these cities is 6.577% faster. This quantitative evidence substantiates the backfire effect of the anticipation of environmental policy, where the delay between a policy’s announcement and its enforcement leads to a short-term surge in pollution levels. For China and other emerging economies, the development of a thorough and deliberate intergovernmental cooperation strategy is critical when formulating environmental policies. It involves synchronizing the efforts of different government levels in applying pollution controls and diminishing the interval of potential intense pollution in the pre-implementation phase.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547773","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 : 2024-07-04DOI: 10.1088/1748-9326/ad5a25
Sidharth Sivaraj, Jakob Zscheischler, Jonathan R Buzan, Olivia Martius, Stefan Brönnimann and Ana M Vicedo-Cabrera
The global health burden associated with exposure to heat is a grave concern and is projected to further increase under climate change. While physiological studies have demonstrated the role of humidity alongside temperature in exacerbating heat stress for humans, epidemiological findings remain conflicted. Understanding the intricate relationships between heat, humidity, and health outcomes is crucial to inform adaptation and drive increased global climate change mitigation efforts. This article introduces ‘directed acyclic graphs’ (DAGs) as causal models to elucidate the analytical complexity in observational epidemiological studies that focus on humid-heat-related health impacts. DAGs are employed to delineate implicit assumptions often overlooked in such studies, depicting humidity as a confounder, mediator, or an effect modifier. We also discuss complexities arising from using composite indices, such as wet-bulb temperature. DAGs representing the health impacts associated with wet-bulb temperature help to understand the limitations in separating the individual effect of humidity from the perceived effect of wet-bulb temperature on health. General examples for regression models corresponding to each of the causal assumptions are also discussed. Our goal is not to prioritize one causal model but to discuss the causal models suitable for representing humid-heat health impacts and highlight the implications of selecting one model over another. We anticipate that the article will pave the way for future quantitative studies on the topic and motivate researchers to explicitly characterize the assumptions underlying their models with DAGs, facilitating accurate interpretations of the findings. This methodology is applicable to similarly complex compound events.
与暴露于高温有关的全球健康负担是一个令人严重关切的问题,预计在气候变化的影响下,这一问题将进一步加剧。生理学研究表明,湿度与温度一起加剧了人类的热应激反应,但流行病学研究结果仍然相互矛盾。了解热量、湿度和健康结果之间错综复杂的关系,对于提供适应信息和推动全球减缓气候变化的努力至关重要。本文介绍了作为因果模型的 "有向无环图"(DAG),以阐明重点关注湿热相关健康影响的流行病学观察研究中的分析复杂性。我们使用 DAG 来描述此类研究中经常被忽视的隐含假设,将湿度描述为混杂因素、中介因素或效应调节因素。我们还讨论了使用湿球温度等综合指数所产生的复杂性。表示与湿球温度相关的健康影响的 DAG 有助于理解将湿度的个体影响与湿球温度对健康的感知影响分开的局限性。我们还讨论了与每个因果假设相对应的回归模型的一般示例。我们的目标不是优先考虑一种因果模型,而是讨论适合代表湿热对健康影响的因果模型,并强调选择一种模型而非另一种模型的意义。我们预计,这篇文章将为未来有关该主题的定量研究铺平道路,并激励研究人员明确描述其模型所依据的 DAG 假设,从而促进对研究结果的准确解释。这种方法适用于类似的复杂复合事件。
{"title":"Heat, humidity and health impacts: how causal diagrams can help tell the complex story","authors":"Sidharth Sivaraj, Jakob Zscheischler, Jonathan R Buzan, Olivia Martius, Stefan Brönnimann and Ana M Vicedo-Cabrera","doi":"10.1088/1748-9326/ad5a25","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5a25","url":null,"abstract":"The global health burden associated with exposure to heat is a grave concern and is projected to further increase under climate change. While physiological studies have demonstrated the role of humidity alongside temperature in exacerbating heat stress for humans, epidemiological findings remain conflicted. Understanding the intricate relationships between heat, humidity, and health outcomes is crucial to inform adaptation and drive increased global climate change mitigation efforts. This article introduces ‘directed acyclic graphs’ (DAGs) as causal models to elucidate the analytical complexity in observational epidemiological studies that focus on humid-heat-related health impacts. DAGs are employed to delineate implicit assumptions often overlooked in such studies, depicting humidity as a confounder, mediator, or an effect modifier. We also discuss complexities arising from using composite indices, such as wet-bulb temperature. DAGs representing the health impacts associated with wet-bulb temperature help to understand the limitations in separating the individual effect of humidity from the perceived effect of wet-bulb temperature on health. General examples for regression models corresponding to each of the causal assumptions are also discussed. Our goal is not to prioritize one causal model but to discuss the causal models suitable for representing humid-heat health impacts and highlight the implications of selecting one model over another. We anticipate that the article will pave the way for future quantitative studies on the topic and motivate researchers to explicitly characterize the assumptions underlying their models with DAGs, facilitating accurate interpretations of the findings. This methodology is applicable to similarly complex compound events.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547771","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}
In boreal summer (July–August) 2022, an unprecedented marine heatwave (MHW) occurred in the northwest Pacific Ocean (NWP), while a record-breaking terrestrial heatwave (THW) hit the Yangtze River Basin (YRB). The temperature anomalies caused by this compound MHW-THW event exceeded climatology by 2.5 standard deviations (SDs), breaking the historical record for nearly 100 years, with severe impacts on the ecosystems and social economy. To investigate the underlying causes, we explored the potential roles of anthropogenic forcing, atmospheric circulation, and ‘triple-dip’ La Niña on this compound event using the Coupled Model Intercomparison Project Phase 6 (CMIP6) multi-model simulations. Results indicate that the 2022-like compound MHW-THW event was extremely unlikely to happen without anthropogenic warming, and that such extreme heatwaves were governed by the climatic mean temperature rather than changes in temperature variability. Notably, the anticyclone circulation patterns and associated high-pressure systems (i.e. western North Pacific subtropical high (WNPSH) and South Asian high (SAH)) increase the probability of a 2022-like MHW-THW event by 3.7 times. However, the La Niña phase has no significant effect on the occurrence probability of such events. We further estimate that the 2022-like MHW-THW event will become 7.5 and 11.4 times more likely under the SSP3-7.0 scenario by the middle and end of the 21st century, respectively. This study demonstrates the contribution of anthropogenic climate change and natural variability to the occurrence of compound MHW-THW events and highlights the urgent need to build mitigation strategies for compound MHW-THW events.
{"title":"Attribution of the unprecedented summer 2022 compound marine and terrestrial heatwave in the Northwest Pacific","authors":"Qiaojun Chen, Delei Li, Jianlong Feng, Jifeng Qi, Liang Zhao and Baoshu Yin","doi":"10.1088/1748-9326/ad5ab0","DOIUrl":"https://doi.org/10.1088/1748-9326/ad5ab0","url":null,"abstract":"In boreal summer (July–August) 2022, an unprecedented marine heatwave (MHW) occurred in the northwest Pacific Ocean (NWP), while a record-breaking terrestrial heatwave (THW) hit the Yangtze River Basin (YRB). The temperature anomalies caused by this compound MHW-THW event exceeded climatology by 2.5 standard deviations (SDs), breaking the historical record for nearly 100 years, with severe impacts on the ecosystems and social economy. To investigate the underlying causes, we explored the potential roles of anthropogenic forcing, atmospheric circulation, and ‘triple-dip’ La Niña on this compound event using the Coupled Model Intercomparison Project Phase 6 (CMIP6) multi-model simulations. Results indicate that the 2022-like compound MHW-THW event was extremely unlikely to happen without anthropogenic warming, and that such extreme heatwaves were governed by the climatic mean temperature rather than changes in temperature variability. Notably, the anticyclone circulation patterns and associated high-pressure systems (i.e. western North Pacific subtropical high (WNPSH) and South Asian high (SAH)) increase the probability of a 2022-like MHW-THW event by 3.7 times. However, the La Niña phase has no significant effect on the occurrence probability of such events. We further estimate that the 2022-like MHW-THW event will become 7.5 and 11.4 times more likely under the SSP3-7.0 scenario by the middle and end of the 21st century, respectively. This study demonstrates the contribution of anthropogenic climate change and natural variability to the occurrence of compound MHW-THW events and highlights the urgent need to build mitigation strategies for compound MHW-THW events.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547775","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}