全球变化背景下安徽近55 a气温时空变化特征

基于安徽省80个气象站的月值气温观测数据,采用线性倾向率、Mann-Kendall突变检验、小波分析和R/S分析等数理统计方法,研究多时间尺度下的气温变化特征。结果表明:1)近55 a安徽省气候呈现明显的暖化趋势,年均气温及春、秋、冬季气温均呈明显上升趋势,其中春季升温幅度最显著,年平均气温在20世纪90年代波动幅度最大;2)年平均气温在1996年发生了突变,与突变前相比,突变后的平均气温增加了0.82℃,年平均气温发生了较大的变化,增暖趋势显著;3)近55 a安徽省年平均气温的变化主要存在5~8 a和10~15 a周期振荡,由小波方差图可以确定年平均气温存在6 a和11 a的主周期;4)安徽省年及四季平均气温的Hurst指数都大于0.5,表明存在显著的Hurst现象,即在不同时间段,该地区的气温时间序列大体上延续历史变化趋势,说明近55 a来安徽省的气温变化存在趋势性成分。春季和冬季Hurst值最高,表明与其他季节相比,春季和冬季的增温持续性最强,是年平均增温的主要贡献者。     

Response of gaseous carbon emissions to low-level salinity increase in tidal marsh ecosystem of the Min River estuary, southeastern China

Although estuarine tidal marshes are important contributors to the emission of greenhouse gases into the atmosphere, the relationship between carbon dioxide(CO_2), methane(CH_4)emission, and environmental factors, with respect to estuarine marshes, has not been clarified thoroughly. This study investigated the crucial factors controlling the emission of CO_2 and CH_4from a freshwater marsh and a brackish marsh located in a subtropical estuary in southeastern China, as well as their magnitude. The duration of the study period was November 2013 to October 2014. Relevant to both the field and incubation experiments, the CO_2 and CH_4emissions from the two marshes showed pronounced seasonal variations. The CO_2 and CH_4emissions from both marshes demonstrated significant positive correlations with the air/soil temperature(p 0.01), but negative correlations with the soil electrical conductivity and the pore water/tide water Cl-and SO_4~(2-)(p 0.01). The results indicate no significant difference in the CO_2 emissions between the freshwater and brackish marshes in the subtropical estuary, whereas there was a difference in the CH_4 emissions between the two sites(p 0.01). Although future sea-level rise and saltwater intrusion could reduce the CH_4 emissions from the estuarine freshwater marshes, these factors had little effect on the CO_2 emissions with respect to an increase in salinity of less than 5‰. The findings of this study could have important implications for estimating the global warming contributions of estuarine marshes along differing salinity gradients.     

Effects of warming on leaf non-structural carbohydrates and carbon and nitrogen isotopes of Cunninghamia lanceolata saplings during different seasons北大核心CSCD

To reveal the response of non-structural carbohydrates (NSC) and carbon and nitrogen isotopes in plant leaves to global warming, we conducted soil warming experiments in the Fujian Sanming Forest Ecosystem and Global Change National Observation and Research Station of China. We designed two treatments: control (CT) and warming (W; cable heating, +4 ℃). Heating cables were installed 20 cm from each other at a depth of 10 cm and were heated in March 2016. In this study, Cunninghamia lanceolata saplings were used to analyze seasonal changes in leaf non-structural carbohydrates, and carbon and nitrogen isotopes. The results showed that (1) warming significantly reduced the soluble sugar, starch, and NSC content of leaves in spring but without any significant difference during other seasons. (2) Leaf δ13C increased significantly in spring and winter after warming, whereas leaf δ15N did not change significantly. (3) No significant correlation was observed between leaf δ13C, δ15N, or NSC content during the warming treatment, but a negative correlation was observed between leaf δ15N, δ13C, and sugar to starch ratio. A positive correlation between leaf δ15N and starch content was identified. In summary, when temperature increases, plants adjust the NSC content during different seasons for osmotic regulation, change the characteristics of the nutrient cycle, and alter the plant water and nutrient use strategies to maintain plant growth. In the future, we should further study the seasonal variation characteristics of NSC content and isotopes and the relationship between NSC content and the carbon and nitrogen cycles in plants under the context of long-term warming. © 2022 Science Press. All rights reserved.     

Values,rules and knowledge: Adaptation as change in the decision context

Responding to global change represents an unprecedented challenge for society. Decision makers tend to address this challenge by framing adaptation as a decision problem, whereby the responses to impacts of change are addressed within existing decision processes centred on defining the decision problem and selecting options. However, this ‘decision-making perspective’ is constrained by societal values and principles, regulations and norms and the state of knowledge. It is therefore unsuitable for addressing complex, contested, cross-scale problems. In this paper we argue that simply broadening the decision-making perspective to account for institutions and values is not enough. We contend the decision-making perspective needs to be connected with a broader ‘decision-context perspective’ that focuses on how the societal system of decision processes affects the manner in which a particular problem is addressed. We describe the decision context as an interconnected system of values, rules and knowledge (vrk). The interaction of systems of vrk both creates and limits the set of practical, permissible decisions; the types of values, rules and knowledge that influence the decision and the capacity for change and transformation in the decision context. We developed a framework to analyse the interactions between values, rules and knowledge and their influence on decision making and decision contexts of adaptation initiatives, and applied it retrospectively to three projects on adaptation to sea-level rise. Our analysis revealed: (1) specific examples of how interactions between vrk systems constrained existing framings of decision making and the development of options for coastal adaptation; (2) limitations in the adaptive management strategies that underpinned the projects and (3) how the linked systems of vrk can allow adaptation practitioners to structure adaptation as a process of co-evolutionary change that enables a broader set of social issues and change processes to be considered. Adaptation projects that focus on the decision context represent a pragmatic alternative to existing decision-focused adaptation. By using the vrk model to diagnose constraints in decision processes, we show how the reframing of adaptation initiatives can reveal new approaches to developing adaptation responses to complex global change problems.     

水库水质监测及分析系统设计研究

水库水质监测及分析系统集控制技术、计算机应用技术、通信技术、地理信息技术和仪表分析技术为一体,可视化展示水库水质动态,并依据水质质量评价规范,分析和评价各监测项目,进行有效的监控预警。系统可根据数学模型对水质进行模拟计算,为水库的管理监督、决策规划、污染防治等工作提供决策支持,同时增强管理部门应对突发性污染事故快速反应能力。     

关于改善中国参与全球环境治理的战略思路

本文对全球环境治理的现状,中国当前在全球环境治理中的作用与面临的挑战,以及中国如何更好地参与全球环境治理进行了系统的总结.主要内容包括:全球环境治理成为全球治理的重要内容,全球环境治理当前由发达国家主导,全球环境治理中各方利益更加分化,非政府组织的影响越来越大,全球环境治理当前进展缓慢;中国日益成为全球环境治理的关注焦点,中国国内环保工作与全球环境治理有着巨大差别,中国国情的不断变化导致在全球环境治理中的立场摇摆;中国参与全球环境治理的能力不足、中国的非政府组织力量薄弱;中国应明确自身在全球环境治理中的利益,加强全球环境治理的意识,从熟悉学习阶段向主动参与制定规则转变,发挥我国环境非政府组织在全球环境治理中的积极作用,开展全球环境治理专项研究,加强全球环境治理人才队伍建设.     

Distributed generation by energy from waste technology: A life cycle perspective

Municipal Solid Waste in general and its organic fraction in particular is a potential renewable and non-seasonal resource. In this work, a life cycle assessment has been performed to evaluate the environmental impacts of two future scenarios using biogas produced from the organic fraction of municipal solid waste (OFMSW) to supply energy to a group of dwellings, respectively comprising distributed generation using solid oxide fuel cell (SOFC) micro-CHP systems and condensing boilers. The London Borough of Greenwich is taken as the reference case study. The system is designed to assess how much energy demand can be met and what is the best way to use the digestible waste for distributed energy purposes.The system is compared with two alternative scenarios fuelled by natural gas: a reference scenario, where the electricity is supplied by the grid and the heat is supplied from condensing boilers, and a fuel cell micro-CHP system. The results show that, although OFMSW alone can only supply between 1% and 4% of the total energy demand of the Borough, a saving of ∼130 tonnes of CO₂ eq per year per dwelling equipped with micro-CHP is still achievable compared with the reference scenario. This is primarily due to the surplus electricity produced by the fuel cell when the micro-CHP unit is operated to meet the heat demand. Use of biogas to produce heat only is therefore a less desirable option compared with combined heat and power production. Further investigation is required to identify locally available feedstock other than OFMSW in order to increase the proportion of energy demand that can be met in this way.     

Discounting and relative consumption

We analyze optimal social discount rates when people derive utility from relative consumption, i.e. their own consumption level relative to the consumption level of others. We compare the social, private, and conventional Ramsey rates. Assuming a positive growth rate, we find that (1) the social discount rate exceeds the private discount rate if the importance of relative consumption increases with consumption, and that (2) the social discount rate is lower than the Ramsey rate given quasi-concavity in own and others’ consumption and risk aversion with respect to others’ consumption. Numerical calculations demonstrate that the latter difference may be substantial and have important implications for long run environmental issues such as global warming.     

Species Extinction in the Marine Environment: Tasmania as a Regional Example of Overlooked Losses in Biodiversity

Abstract:  We used Tasmania as a case example to question the consensus that few marine species have recently become extinct or are approaching extinction. Threats to marine and estuarine species—primarily in the form of climate change, invasive species, fishing, and catchment discharges—are accelerating, fully encompass species ranges, and are of sufficient magnitude to cause extinction. Our ignorance of declining biodiversity in the marine environment largely results from an almost complete lack of systematic broad-scale sampling and an overreliance on physicochemical data to monitor environmental trends. Population declines for marine species approaching extinction will generally go unnoticed because of the hidden nature of their environment and lack of quantitative data.     

The Future of Tropical Species on a Warmer Planet

Abstract: Modern global temperature and land cover and projected future temperatures suggest that tropical forest species will be particularly sensitive to global warming. Given a moderate greenhouse gas emissions scenario, fully 75% of the tropical forests present in 2000 will experience mean annual temperatures in 2100 that are greater than the highest mean annual temperature that supports closed‐canopy forest today. Temperature‐sensitive species might extend their ranges to cool refuges, defined here as areas where temperatures projected for 2100 match 1960s temperatures in the modern range. Distances to such cool refuges are greatest for equatorial species and are particularly large for key tropical forest areas including the Amazon and Congo River Basins, West Africa, and the upper elevations of many tropical mountains. In sum, tropical species are likely to be particularly sensitive to global warming because they are adapted to limited geographic and seasonal variation in temperature, already lived at or near the highest temperatures on Earth before global warming began, and are often isolated from cool refuges. To illustrate these three points, we examined the distributions and habitat associations of all extant mammal species. The distance to the nearest cool refuge exceeded 1000 km for more than 20% of the tropical and less than 4% of the extratropical species with small ranges. The biological impact of global warming is likely to be as severe in the tropics as at temperate and boreal latitudes.