With offshore becoming the main battlefield of wind power generation,modular multilevel converter-based high-voltage DC(MMC-HVDC)transmission technology has become an ideal solution for offshore wind power integration...With offshore becoming the main battlefield of wind power generation,modular multilevel converter-based high-voltage DC(MMC-HVDC)transmission technology has become an ideal solution for offshore wind power integration and received rapid development.However,wideband oscillation events have seriously threatened stable operation of power systems.By far,existing oscillation mitigation methods are usually designed for specific oscillation cases and are not capable of mitigating wideband oscillations.In order to mitigate various oscillations adaptively,this article proposes an adaptive wideband oscillation mitigation control for MMC-HVDC system connected to offshore wind farms.Analytical wideband impedance models of the wind farm side MMC(WFMMC)and offshore wind farm composed of permanent-magnetic synchronous generator-based wind turbine generators(PMSG-WTGs)are derived,respectively,which are verified by measured impedances from time-domain simulations.Then,a wideband oscillation mechanism is revealed by impedance-frequency characteristics.On this basis,an adaptive wide band oscillation mitigation control is proposed,and its working principle as well as implementation process are elaborated.Case studies of a sub-/super-synchronous oscillation(SSO)event and a high-frequency oscillation(HFO)event of an offshore wind farm with MMC-HVDC system are carried out to verify effectiveness of the proposed adaptive wideband oscillation mitigation control.展开更多
Mitigation and adaptation are two principle strategies for managing human-induced climate change. Agriculture plays a duet role in climate change. It has been a major source of greenhouse gases to the atmosphere. It i...Mitigation and adaptation are two principle strategies for managing human-induced climate change. Agriculture plays a duet role in climate change. It has been a major source of greenhouse gases to the atmosphere. It is also one of the sectors most vulnerable to the risks and impacts of global climate change. This paper first indentified the mitigative and adaptative options and potential in agriculture, then addressed the integrated analysis of mitigation and adaptation and its benefits for agriculture. Finally, it discussed the implications to Chinese agriculture in dealing with the global climate change.展开更多
Climate change has become one of the key issues affecting global society and economic development,and it is related to the sustainable development of mankind and the earth’s ecological system.Firstly,this research be...Climate change has become one of the key issues affecting global society and economic development,and it is related to the sustainable development of mankind and the earth’s ecological system.Firstly,this research begins with the important international conferences and agreements on Global Climate Governance,and analyzes the recent progress of the Paris Agreement,the Marrakech climate conference and the major progress of China&US climate cooperation and China’s contribution.Secondly,from the perspective of China’s adaptation and response to climate change,the main progress of climate change in China is reviewed from a multi-level perspective.The main scientific and technological progress and achievements in China’s response to climate change have been tracked.Finally,from the environmental risk areas,the future risks of climate change are predicted from six aspects,to contribute to the scientific and technological support program for climate change governance.展开更多
Global large-scale urbanization and climate change have become indisputable scientific facts yet are unresolved issues,and are a common concern for mankind.The relationship between these two topics is unclear and it i...Global large-scale urbanization and climate change have become indisputable scientific facts yet are unresolved issues,and are a common concern for mankind.The relationship between these two topics is unclear and it is not known how to deal appropriately at the scientific level with climate change in the process of urbanization.Further exploration of the science,management and practice,are needed to achieve global and regional sustainadevelopment.This paper first considers the basic facts concerning mass urbanization and climate change and summarizes the interactions and possible mechanisms of urbanization and climate change.Urbanization leads to the heat island effect,an uneven distribution of precipitation and extreme weather,together with a local-regional-global multi-scale superposition effect,which aggravates the consequences of global climate change.The impact of climate change on urbanization is mainly manifested in aspects such as changes of energy consumption,mortality,and the spread of infectious diseases,sea level rise,extreme weather damage to infrastructure,and water shortages.This paper also briefly reviews relevant international research programs and action coalitions and puts forward an analysis framework multi-dimensional sustainable urbanization which can adapt to and mitigate climate change,from the perspective of the four key dimensions—population,land use,economy,and society.It is imperative that we strengthen the interdisciplinary activities involving the natural and social sciences,take urbanization and other human activities into consideration of the land-atmosphere system,and explore the human-land-atmosphere coupling process.The adaptation and mitigation from the perspective of human activities,as represented by urbanization,might be the most critical and realistic way to deal with climate change.展开更多
Dynamic</span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> urbanization of African cities has created development traj...Dynamic</span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> urbanization of African cities has created development trajectories that face systemic challenges in the provision of sustainable and ecologically resilient urban environments. The specific challenges include extensive unregulated growth with informal settlements reflecting poor service levels and high poverty indices, inadequacy in </span><span style="font-family:Verdana;">provision</span><span style="font-family:Verdana;"> of basic services in health, water, housing, transport </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> communication infrastructure, high reliance on biomass fuels, exposure to environmental stress </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> implausible climate change coping and mitigation mechanisms among others. </span><span style="font-family:Verdana;">Review</span><span style="font-family:Verdana;"> of extensive literature and synthesis of existing bodies of knowledge on the ecological and management perspectives of urban environments revealed many gaps and understanding of urban transformation processes. The purpose of this review was to contextualize credible pathways for optimization of both ecosystem goods and services from green urban landscapes (Green infrastructure) and non-green infrastructure to ensure sustainable and ecologically resilient urban environments. Attempts were made to rationalize and validate through discussions the benefits of managed urban ecosystems for African cities. </span><span style="font-family:Verdana;">On the basis of</span><span style="font-family:Verdana;"> the evidence from the literature, it is concluded that urban development trajectories that do not embrace multifaceted approaches that deliberately retain and maintain green infrastructure in the urban environment may not be cost-effective. It is recommended that systematic integration of urban forestry concepts in urban planning that involves communities, local and national governments, business entrepreneurs </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> public and private research institutions provides tenable frameworks for addressing current and future challenges of urbanization in Africa.展开更多
We chose a definition of heatwaves (HWs) that has ~4-year recurrence frequency at world hot spots. We first examined the 1940-2022 HWs climatology and trends in lifespan, severity, spatial extent, and recurrence frequ...We chose a definition of heatwaves (HWs) that has ~4-year recurrence frequency at world hot spots. We first examined the 1940-2022 HWs climatology and trends in lifespan, severity, spatial extent, and recurrence frequency. HWs are becoming more frequent and more severe for extratropical mid- and low-latitudes. To euphemize HWs, we here propose a novel clean energy-tapping concept that utilizes the available nano-technology, micro-meteorology knowledge of temperature distribution within/without buildings, and radiative properties of earth atmosphere. The key points for a practical electricity generation scheme from HWs are defogging, insulation, and minimizing the absorption of infrared downward radiation at the cold legs of the thermoelectric generators. One sample realization is presented which, through relay with existing photovoltaic devices, provides all-day electricity supply sufficient for providing air conditioning requirement for a residence (~2000-watt throughput). The provision of power to air conditioning systems, usually imposes a significant stress on traditional city power grids during heatwaves.展开更多
Indigenous agroforestry systems have been practiced for centuries in the Himalaya Mountains and adjoining regions.With the increase of climate change associated risks,enhanced understanding of the impact of climate ch...Indigenous agroforestry systems have been practiced for centuries in the Himalaya Mountains and adjoining regions.With the increase of climate change associated risks,enhanced understanding of the impact of climate change and related phenomena on the potential distribution of agroforestry is increasingly useful and necessary,for both maintaining and improving yield and ecosystem function.In particular,展开更多
The Green Climate Fund （GCF） has been one of the core issues of the world climate summits under the United Nations Framework Convention on Climate Change （UNFCCC） in recent years. However, the GCF has not progress...The Green Climate Fund （GCF） has been one of the core issues of the world climate summits under the United Nations Framework Convention on Climate Change （UNFCCC） in recent years. However, the GCF has not progressed smoothly, and currently there are no satisfactory schemes for raising and distributing the fund. This paper first discusses how to finance the GCF among Annex II countries. It introduces the ＇preference score compromises＇ （PSC） approach which is based on environmental responsibility and economic capacity, with historical emissions as an indicator for environmental responsibility and GDP as indicator for economic capacity. The results show that the United States and the European Union are the two largest contributors to the GCF, sponsoring more than 80% of the funds. Second, we discuss how to allocate the funds among non-Annex II parties. The ＇adaptation needs＇ （AN） approach, which takes account of economic strength and climate damages, is proposed to achieve the adaptation purpose of the GCF, and the results reveal that African countries with high levels of climate vulnerability could get most funds, with a share of almost 30%. Regarding the mitigation purpose of the GCF, this research introduces two approaches： the ＇carbon reduction contribution＇ （CC） approach and the ＇incremental cost＇ （IC） approach. Both approaches could achieve significant reductions in carbon emissions in non-Annex II parties, whereas the latter may provide limited adaptation finance but result in more mitigation effects. This paper also develops a method to combine abatement efficiency and adaptation fairness of the GCF, and we find that with an equal split between the AN and CC （or AN and IC） approaches, the amount of USD 100 billion could finance an emissions reduction of 1613 MtCO2 （2477 MtCO2）, while allocating USD 16 （or USD 9） per capita for adaptation in non-Annex II parties. The schemes proposed may be useful for promoting the development of the GCF in the future.展开更多
基金supported in part by the National Natural Science Foundation of China(51907125)in part by the China Three Gorges Corporation(202103026)。
文摘With offshore becoming the main battlefield of wind power generation,modular multilevel converter-based high-voltage DC(MMC-HVDC)transmission technology has become an ideal solution for offshore wind power integration and received rapid development.However,wideband oscillation events have seriously threatened stable operation of power systems.By far,existing oscillation mitigation methods are usually designed for specific oscillation cases and are not capable of mitigating wideband oscillations.In order to mitigate various oscillations adaptively,this article proposes an adaptive wideband oscillation mitigation control for MMC-HVDC system connected to offshore wind farms.Analytical wideband impedance models of the wind farm side MMC(WFMMC)and offshore wind farm composed of permanent-magnetic synchronous generator-based wind turbine generators(PMSG-WTGs)are derived,respectively,which are verified by measured impedances from time-domain simulations.Then,a wideband oscillation mechanism is revealed by impedance-frequency characteristics.On this basis,an adaptive wide band oscillation mitigation control is proposed,and its working principle as well as implementation process are elaborated.Case studies of a sub-/super-synchronous oscillation(SSO)event and a high-frequency oscillation(HFO)event of an offshore wind farm with MMC-HVDC system are carried out to verify effectiveness of the proposed adaptive wideband oscillation mitigation control.
文摘Mitigation and adaptation are two principle strategies for managing human-induced climate change. Agriculture plays a duet role in climate change. It has been a major source of greenhouse gases to the atmosphere. It is also one of the sectors most vulnerable to the risks and impacts of global climate change. This paper first indentified the mitigative and adaptative options and potential in agriculture, then addressed the integrated analysis of mitigation and adaptation and its benefits for agriculture. Finally, it discussed the implications to Chinese agriculture in dealing with the global climate change.
基金Sponsored by Beijing Social Science Foundation Project(19JDGLA008)China Postdoctoral Science Foundation(2019T120114+2 种基金 2019M650756)National Natural Science Foundation of China(41801064)Central Asia Atmospheric Sciences Research(CAAS201804)
文摘Climate change has become one of the key issues affecting global society and economic development,and it is related to the sustainable development of mankind and the earth’s ecological system.Firstly,this research begins with the important international conferences and agreements on Global Climate Governance,and analyzes the recent progress of the Paris Agreement,the Marrakech climate conference and the major progress of China&US climate cooperation and China’s contribution.Secondly,from the perspective of China’s adaptation and response to climate change,the main progress of climate change in China is reviewed from a multi-level perspective.The main scientific and technological progress and achievements in China’s response to climate change have been tracked.Finally,from the environmental risk areas,the future risks of climate change are predicted from six aspects,to contribute to the scientific and technological support program for climate change governance.
基金National Natural Science Foundation of China,No.41822104,No.42042027The Chinese Academy of Sciences Basic Frontier Science Research Program from 0 to 1 Original Innovation Project,No.ZDBS-LY-DQC005+2 种基金The Strategic Priority Research Program of Chinese Academy of Sciences,No.XDA23100301The Youth Innovation Promotion Association of the Chinese Academy of Sciences,No.2017072。
文摘Global large-scale urbanization and climate change have become indisputable scientific facts yet are unresolved issues,and are a common concern for mankind.The relationship between these two topics is unclear and it is not known how to deal appropriately at the scientific level with climate change in the process of urbanization.Further exploration of the science,management and practice,are needed to achieve global and regional sustainadevelopment.This paper first considers the basic facts concerning mass urbanization and climate change and summarizes the interactions and possible mechanisms of urbanization and climate change.Urbanization leads to the heat island effect,an uneven distribution of precipitation and extreme weather,together with a local-regional-global multi-scale superposition effect,which aggravates the consequences of global climate change.The impact of climate change on urbanization is mainly manifested in aspects such as changes of energy consumption,mortality,and the spread of infectious diseases,sea level rise,extreme weather damage to infrastructure,and water shortages.This paper also briefly reviews relevant international research programs and action coalitions and puts forward an analysis framework multi-dimensional sustainable urbanization which can adapt to and mitigate climate change,from the perspective of the four key dimensions—population,land use,economy,and society.It is imperative that we strengthen the interdisciplinary activities involving the natural and social sciences,take urbanization and other human activities into consideration of the land-atmosphere system,and explore the human-land-atmosphere coupling process.The adaptation and mitigation from the perspective of human activities,as represented by urbanization,might be the most critical and realistic way to deal with climate change.
文摘Dynamic</span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> urbanization of African cities has created development trajectories that face systemic challenges in the provision of sustainable and ecologically resilient urban environments. The specific challenges include extensive unregulated growth with informal settlements reflecting poor service levels and high poverty indices, inadequacy in </span><span style="font-family:Verdana;">provision</span><span style="font-family:Verdana;"> of basic services in health, water, housing, transport </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> communication infrastructure, high reliance on biomass fuels, exposure to environmental stress </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> implausible climate change coping and mitigation mechanisms among others. </span><span style="font-family:Verdana;">Review</span><span style="font-family:Verdana;"> of extensive literature and synthesis of existing bodies of knowledge on the ecological and management perspectives of urban environments revealed many gaps and understanding of urban transformation processes. The purpose of this review was to contextualize credible pathways for optimization of both ecosystem goods and services from green urban landscapes (Green infrastructure) and non-green infrastructure to ensure sustainable and ecologically resilient urban environments. Attempts were made to rationalize and validate through discussions the benefits of managed urban ecosystems for African cities. </span><span style="font-family:Verdana;">On the basis of</span><span style="font-family:Verdana;"> the evidence from the literature, it is concluded that urban development trajectories that do not embrace multifaceted approaches that deliberately retain and maintain green infrastructure in the urban environment may not be cost-effective. It is recommended that systematic integration of urban forestry concepts in urban planning that involves communities, local and national governments, business entrepreneurs </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> public and private research institutions provides tenable frameworks for addressing current and future challenges of urbanization in Africa.
文摘We chose a definition of heatwaves (HWs) that has ~4-year recurrence frequency at world hot spots. We first examined the 1940-2022 HWs climatology and trends in lifespan, severity, spatial extent, and recurrence frequency. HWs are becoming more frequent and more severe for extratropical mid- and low-latitudes. To euphemize HWs, we here propose a novel clean energy-tapping concept that utilizes the available nano-technology, micro-meteorology knowledge of temperature distribution within/without buildings, and radiative properties of earth atmosphere. The key points for a practical electricity generation scheme from HWs are defogging, insulation, and minimizing the absorption of infrared downward radiation at the cold legs of the thermoelectric generators. One sample realization is presented which, through relay with existing photovoltaic devices, provides all-day electricity supply sufficient for providing air conditioning requirement for a residence (~2000-watt throughput). The provision of power to air conditioning systems, usually imposes a significant stress on traditional city power grids during heatwaves.
文摘Indigenous agroforestry systems have been practiced for centuries in the Himalaya Mountains and adjoining regions.With the increase of climate change associated risks,enhanced understanding of the impact of climate change and related phenomena on the potential distribution of agroforestry is increasingly useful and necessary,for both maintaining and improving yield and ecosystem function.In particular,
基金Supports from the National Natural Science Foundation of China under Grant No.71210005 and No.71273253
文摘The Green Climate Fund （GCF） has been one of the core issues of the world climate summits under the United Nations Framework Convention on Climate Change （UNFCCC） in recent years. However, the GCF has not progressed smoothly, and currently there are no satisfactory schemes for raising and distributing the fund. This paper first discusses how to finance the GCF among Annex II countries. It introduces the ＇preference score compromises＇ （PSC） approach which is based on environmental responsibility and economic capacity, with historical emissions as an indicator for environmental responsibility and GDP as indicator for economic capacity. The results show that the United States and the European Union are the two largest contributors to the GCF, sponsoring more than 80% of the funds. Second, we discuss how to allocate the funds among non-Annex II parties. The ＇adaptation needs＇ （AN） approach, which takes account of economic strength and climate damages, is proposed to achieve the adaptation purpose of the GCF, and the results reveal that African countries with high levels of climate vulnerability could get most funds, with a share of almost 30%. Regarding the mitigation purpose of the GCF, this research introduces two approaches： the ＇carbon reduction contribution＇ （CC） approach and the ＇incremental cost＇ （IC） approach. Both approaches could achieve significant reductions in carbon emissions in non-Annex II parties, whereas the latter may provide limited adaptation finance but result in more mitigation effects. This paper also develops a method to combine abatement efficiency and adaptation fairness of the GCF, and we find that with an equal split between the AN and CC （or AN and IC） approaches, the amount of USD 100 billion could finance an emissions reduction of 1613 MtCO2 （2477 MtCO2）, while allocating USD 16 （or USD 9） per capita for adaptation in non-Annex II parties. The schemes proposed may be useful for promoting the development of the GCF in the future.
