气候变化·城市化·长江三角洲

长江三角洲，是中国经济社会最发达、人口和产业最密集、发展最具活力的地区之一，正在成长为具有重要国际影响的世界级城市群，在中国经济社会发展中具有举足轻重的地位。长江三角洲的城市化与建设环境互为影响。一方面，用2008年数据概括了长江三角洲城市化现状特征，重点分析了长江三角洲城市化的发展趋势是城市化过程进一步加速；另一方面，综述了常见三角洲海平面上升研究，在未来20 a长江三角洲海平面上升估计将达到220～380 mm；在未来50 a，长江三角洲海平面上升保守的估计将达到270~610 mm。未来气候变化导致海平面上升，必然对长江三角洲城市化过程造成影响，主要是：土地淹没面积大，洪涝灾害加剧，影响生产和能源，以及进一步滋生环境问题。     

海平面上升对长江三角洲地区的影响评价研究

气候变暖导致的全球性海平面加速上升严重威胁着沿海国家和地区的持续发展。作为世界五大三角洲之一的长江三角洲及其邻近地区，其地势低平，人口稠密，经济发达，因而所受海平观上升的威胁更加严重。根据ＩＰＣＣ拟定的方案，对于未来海平面另速上升所造成的沿海地区脆弱性影响评价，取海平面上升３０、６５和１００ｃｍ三种情况进行研究，本地区内岸段是我国海岸侵蚀最为严重的岸段。长江口的潮水上溯使盐水入侵、造成水质恶化，海     

中国海平面在上升

据国家测绘局宣布,中国海平面每年上升2～3mm。同时某些沿海地区随着地下水的过量开采和其它因素,相继出现地面沉降现象。海岸带环境受到较大影响。我国测绘局的专家研究认为,未来海面呈上升趋势。分析表明,整个中国东海和南海沿岸海平面在过去100年中分别上升19cm和20cm。     

中国海岸湿地环境特点与开发利用

海岸湿地是由低地、滩涂与生物群落组合的海岸环境。中国海岸湿地环境受季风波浪、潮汐与大河影响的河海交互作用为特征，地跨39个纬度带，其面积约占中国湿地总面积的1/5。按成因与表相可分为：河口芦苇、草滩湿地，平原海岸草滩盐沼湿地及在华南隐蔽港湾顶部红树林沼泽湿地3种类型。均具有潮上带、潮间带与潮下带分带特性。海岸湿地是珍贵的新生空间资源，但由于滥伐垦殖、外来生物种属入侵危害、陆源水沙减少及海平面上升招致海岸侵蚀、盐潮入侵与内涝频繁等灾害影响，海岸湿地环境质量下降，面临着解决海岸湿地生态保护与沿海人民生计这一新生矛盾问题。需沿流域进行陆海结合的系统研究与对比总结，找出湿地保护与开发的临界度，全面规划实施。     

全球气候变化背景下上海市风暴潮灾害情景下脆弱性评估

上海地处长三角地区,地势低平,潮滩与湿地广布,未来海平面上升加剧的风暴潮灾害、咸水入侵等灾害,将给该地区的社会经济发展带来巨大损失。应用情景模拟法和脆弱性评估法来评估上海市河口海岸地区的脆弱性,定量化研究了2030年和2050年海平面上升、地面沉降和风暴潮灾害的情景下的威胁区域。到2030年和2050年海平面将分别上升86.6mm和185.6mm,中心城区的地面沉降将达0.87~60.29cm和1.56~108.52cm,上海市将面临类似9711号台风的威胁。在此情景以及现有的防灾基础之上,对上海市河口海岸地区进行脆弱性评估。结果表明应对风暴潮最脆弱的地区是黄浦江两岸的低洼地区。在类似9711台风的影响下,2030年上海的脆弱性指数相对较低,主要脆弱区域集中在奉贤和南汇的交界处、崇明县的横沙岛和长兴岛以及黄浦江两岸的低洼地区,此时,暴露于0.5m以上的人口为62万人,占总人口的1.86%,经济损失为1 152、1 372、1 632亿元(分别在经济增速为8%、9%、10%的情景下),占全市国内生产总值的1.5%;2050年,上海市脆弱性急剧升高,脆弱性区域扩大35.46%,分布面积十分广泛,在类似9711号台风的影响下,暴露于0.5m以上的人口达到748万人,占总人口的21.66%,经济损失将高达105 581、151 248、215 959亿元(分别在经济增速为8%、9%、10%的情景下),占全市国内生产总值的29.6%。这些结果应当引起有关部门对于未来海平面上升潜在影响的警惕。     

海岸带土地开发利用及生态环境效应研究简述

海岸带土地利用变化是影响海岸带生态环境的一个重要方面，也是目前国内外学术界广为关注和研究的热点问题，研究海岸带土地利用变化及其对生态环境的影响对于了解区域的生态环境演变乃至全球变化具有重要意义。分析海岸带土地利用变化研究在全球变化研究中的地位，阐述海岸带地区土地利用变化及生态环境效应研究，对研究全球气候变化、海平面上升、陆地与海洋交互作用及由此引起的岸线变迁、入海营养盐和悬浮物及沉积物等物质通量变化、海岸带生物多样性、海岸带区域乃至整个全球C、N等物质总循环等都具有重要意义。基于以上研究，简述海岸带土地利用变化及其对生态环境影响研究进展，总结分析海岸带土地利用变化及环境效应影响研究目标和重点研究内容     

江苏省环境与人口、经济的协调发展分析——基于环境安全视角

协调发展既是国民经济乐观发展的客观要求,同时也是人类可持续发展不可或缺的组成部分。江苏省协调发展问题的研究有利于解决环境问题的定位,发现环境发展中的薄弱点与发展潜力,促进环境与人口、经济的协调发展。以环境安全理论为依托,以强调协调发展为出发点,建立江苏省环境与人口、经济系统的协调发展指标体系,应用改进的层次分析法（AHP）及变异系数法权重均值赋权,借鉴模糊数学中隶属度函数来计算协调系数。结果表明：2001~2010年江苏省环境与人口、经济系统的平均协调水平处于基本协调状态,并且有稳中上升的趋势,协调发展前景乐观;同时分析并提出了建立健全江苏省协调发展机制、探讨环境安全维护体系建设、制订缓解人口压力政策等建议     

气候变化对中国海洋和海岸带的影响、风险与适应对策

本文评估了20世纪中叶以来全球和中国海洋气候驱动因子(致灾因子)的变化及其对中国海洋和海岸带的影响和风险。结果表明:①自20世纪中叶以来,海洋升温、海平面上升、台风-风暴潮,以及海洋热浪等海洋气候致灾因子的危险性(强度、频率和范围等)显著增加。②海洋升温引起海洋物候的显著变迁,导致中国海洋物种组成和地理分布发生变化,以及赤潮、绿潮和大型水母暴发性增殖等生态灾害频繁发生;中国沿海海平面持续上升对红树林和河口等滨海湿地典型生境造成威胁,频繁的海洋热浪引起热带珊瑚加速退化并屡屡造成海水养殖业的重大损失。③近几十年来,大规模围填海、污染物排放和过度渔业捕捞等人类活动增加了中国海洋和海岸带生态系统的暴露度和脆弱性,加剧中国滨海湿地面积的减少、湿地生境的退化、生物多样性和生态系统稳定性的下降,导致中国近海重要海洋渔业经济种类的低龄化、小型化,以及渔业资源的严重衰退。④海平面的上升还加大了海岸侵蚀、海水入侵与河口区咸潮入侵的影响,以及台风-风暴潮对沿海地区的洪涝灾害影响和对沿海经济社会造成的损失。⑤未来不同气候情景下(温室气体从低排放到高排放情景,RCP2.6,4.5和8.5),到21世纪末,中国海洋温度和海平面将有大幅度上升,可能成为全球海洋变化最为显著的区域之一,沿海许多地区当前百年一遇的极值水位事件将变为几年一遇甚至低于一年一遇(RCP8.5),沿海地区很可能面临更严重的灾害风险。为此,本文进一步分析并讨论了中国海洋和海岸带地区应对气候变化的若干适应对策措施以及不确定性问题,以期为保障中国沿海地区经济社会的可持续发展提供科学参考。     

海洋的变化及其对中国气候的作用

本文重点分析了气候变化背景下海洋的变化及其对中国气候的作用,评估了中国近海及相邻大洋对气候变化的响应、未来变化及其对中国气候的影响。结果表明:①1958—2018年,特别是1970年代末以来,全球和中国海洋明显变暖,且中国海洋升温高于同时段全球平均,主要归因于黑潮暖水入侵中国近海陆架的年代际增强;在不同气候情景下(温室气体从低到高排放的情景,RCP2.6,4.5,8.5)中国近海尤其是东中国海(渤海、黄海和东海)可能成为全球海洋升温最高的海区之一。1970年代中期以来,中国东海和南海海表盐度呈现下降趋势。1970年代末以来,中国近海环流变化显著,黑潮入侵东中国海陆架以及通过吕宋海峡入侵南海出现年代际增强,冬季黄海暖流以及南海上层环流年代际减弱。②20世纪以来,全球海平面上升速率约1.5±0.4 mm/a,主要贡献来自海水热膨胀和陆地冰川冰盖融化;2006年以来,全球海平面上升明显加速,上升速率达3.6 mm/a。1980年迄今,中国沿海海平面上升速率为3.4 mm/a,高于同时段全球平均;在不同气候情景下海平面将持续上升,当前沿海地区百年一遇极端水位的重现期将显著缩短。③1970年代之后,热带海洋的海温分布如厄尔尼诺信号出现年代际变化,厄尔尼诺显著增强,持续时间更持久;并且,1990年之后,中部型厄尔尼诺趋于频发,发展年夏季长江流域降水偏少、气温偏高,华南降水偏多,次年春季华南降水偏少,而东部型厄尔尼诺的影响则大致相反;未来厄尔尼诺对中国气候的影响预估有较大不确定性。印度洋海盆增暖明显加强,与此相关的是中国东部高温天气频发。1977年以来,全球超强台(飓)风和海洋热浪等极端事件趋频、趋强。④中国近海总体可能是大气CO_2的汇,每年从大气中吸收约10.8 TgC的CO_2。长江口和珠江口及附近海域有长期酸化和溶解氧降低的现象,但近海碳源汇格局及酸化的长期变化仍不够清楚。此外,未来中国近海盐度、环流、强台风和海洋热浪的变化,以及海洋的碳源汇、酸化和溶解氧的观测和研究亟须加强。     

全球变化对长江三角洲土地持续利用的影响及其对策

全球变化对区域土地持续利用的影响表现为其多方面内容从不同侧面直接或间接地对区域土地利用生产性、安全性、保持性、可行性和接受性产生影响。在长江三角洲地区 ,全球变化对土地持续利用的影响主要表现为不利的方面 :( 1)海平面上升导致土地面积减少及土壤性质恶化 ;( 2 )自然灾害增多导致土地利用安全性降低 ;( 3)酸雨危害加重导致土地生态环境恶化 ;( 4 )地表植被减少及湿润指数降低导致土地退化加剧。针对以上问题 ,应采取以下对策以促进长江三角洲土地持续利用 :( 1)加强全球变化监测与预警 ;( 2 )制定适应于全球变化的土地持续利用规划 ;( 3)增强土地利用对全球变化的应变能力 ;( 4 )加强全球合作 ,减缓不利于人类生存的全球变化速度。     

Deltas at risk

The long-term sustainability of populated deltas is often more affected by large-scale engineering projects than sea-level rise associated with global warming and the global ocean volume increase. On deltas, the rate of relative eustatic sea-level rise is often smaller than the rate for isostatic-controlled subsidence and of the same order of magnitude as natural sediment compaction. Accelerated compaction associated with petroleum and groundwater mining can exceed natural subsidence rates by an order of magnitude. The reduction in sediment delivery to deltas due to trapping behind dams, along with the human control of routing river discharge across delta plains, contributes to the sinking of world deltas. Consequences include shoreline erosion, threatened mangroves swamps and wetlands, increased salinization of cultivated land, and hundreds of millions of humans put at risk.     

Sustainable Development in Small Island Developing States

This paper explores the status of sustainable development in small island developing states (SIDS), through the presentation of a case study on the Maldives, which is a typical small island developing state in the Central Indian Ocean. At the outset, a brief history of sustainable development as related to SIDS on the international agenda is outlined, starting from Rio to Barbados to Johannesburg. SIDS are expected to face many challenges and constraints in pursuing sustainable development due to their ecological fragility and economic vulnerability. It is the position of this paper that issues related to environmental vulnerability are of the greatest concern. A healthy environment is the basis of all life-support systems, including that of human well-being and socio-economic development. Priority environmental problems are: climate change and sea-level rise, threats to biodiversity, threats to freshwater resources, degradation of coastal environments, pollution, energy and tourism. Among these, climate change and its associated impacts are expected to pose the greatest threat to the environment and therefore to sustainable development. For small islands dependent on fragile marine ecosystems, in particular on coral reefs, for their livelihoods and living space, adverse effects of climate change such as increased frequency of extreme weather events and sea-level rise will exacerbate the challenges they already face. It is concluded that the paper path from Rio to Barbados to Johannesburg has made significant progress. However, much remains to be done at the practical level, particularly by the developed countries in terms of new and additional efforts at financial and technical assistance, to make sustainable development a reality for SIDS.     

Sea-Level Rise in Public Science Writing: History,Science and Reductionism

Sea-level rise is a dramatic effect of climate change, with profound implications for societies around the world. In the past few years, a rush of literary non-fiction books have appeared that aim to explain the threat of rising seas to the public. This paper critiques how sea-level rise is framed in many of those books, on two accounts. First, anthropogenic sea-level change is frequently framed by accounts of natural variations of sea level in earth history, focusing on geological rather than societal processes. Second, single and sudden floods are often used to exemplify sea-level rise in ways that draw attention away from incremental environmental change in favour of fast-paced but de-contextualized events. The paper argues that both these frames de-politicize sea-level rise and may steer public understanding and discussion away from relevant social, cultural, and ethical considerations. As examples of climate reductionism, these depictions may obstruct rather than facilitate appropriate negotiations in response to predicted sea-level rise.     

Heading for the hills: climate-driven community relocations in the Solomon Islands and Alaska provide insight for a 1.5 °C future

Whilst future air temperature thresholds have become the centrepiece of international climate negotiations, even the most ambitious target of 1.5 °C will result in significant sea-level rise and associated impacts on human populations globally. Of additional concern in Arctic regions is declining sea ice and warming permafrost which can increasingly expose coastal areas to erosion particularly through exposure to wave action due to storm activity. Regional variability over the past two decades provides insight into the coastal and human responses to anticipated future rates of sea-level rise under 1.5 °C scenarios. Exceeding 1.5 °C will generate sea-level rise scenarios beyond that currently experienced and substantially increase the proportion of the global population impacted. Despite these dire challenges, there has been limited analysis of how, where and why communities will relocate inland in response. Here, we present case studies of local responses to coastal erosion driven by sea-level rise and warming in remote indigenous communities of the Solomon Islands and Alaska, USA, respectively. In both the Solomon Islands and the USA, there is no national government agency that has the organisational and technical capacity and resources to facilitate a community-wide relocation. In the Solomon Islands, communities have been able to draw on flexible land tenure regimes to rapidly adapt to coastal erosion through relocations. These relocations have led to ad hoc fragmentation of communities into smaller hamlets. Government-supported relocation initiatives in both countries have been less successful in the short term due to limitations of land tenure, lacking relocation governance framework, financial support and complex planning processes. These experiences from the Solomon Islands and USA demonstrate the urgent need to create a relocation governance framework that protects people’s human rights.     

Evaluation of the Design Features of Interactive Sea-Level Rise Viewers for Risk Communication

Interactive sea-level rise viewers (ISLRVs) are digital tools used to communicate about impacts of sea-level rise (SLR) and support decision-making. This study characterizes how ISLRVs communicate about SLR-related risks and provide decision-making support. It identifies key themes about fostering accurate mental models of SLR processes, informing about inundation likelihood, communicating about related social and ecological risks, and providing features users can apply to specific tasks. We present a framework for understanding this type of communication tool that designers can use to develop robust ISLRVs that can support audiences’ understanding and decision-making needs, and contribute to enhancement of coastal resiliency.     

河西地区的生态建设与可持续农业发展战略及对策

本文分析了河西地区主要生态环境问题的现状和成因，认为人类不合理的经济活动和人口压力破坏了干旱区复合生态系统的良性循环维持机理，导致区域的水、土、生态环境之间的平衡被打破，使区域生态环境劣变。对此，文章提出了河西地区生态建设与可持续农业发展的对策建议。     

What are the implications of sea-level rise for a 1.5, 2 and 3 °C rise in global mean temperatures in the Ganges-Brahmaputra-Meghna and other vulnerable deltas?

Even if climate change mitigation is successful, sea levels will keep rising. With subsidence, relative sea-level rise represents a long-term threat to low-lying deltas. A large part of coastal Bangladesh was analysed using the Delta Dynamic Integrated Emulator Model to determine changes in flood depth, area and population affected given sea-level rise equivalent to global mean temperature rises of 1.5, 2.0 and 3.0 °C with respect to pre-industrial for three ensemble members of a modified A1B scenario. Annual climate variability today (with approximately 1.0 °C of warming) is potentially more important, in terms of coastal impacts, than an additional 0.5 °C warming. In coastal Bangladesh, the average depth of flooding in protected areas is projected to double to between 0.07 and 0.09 m when temperatures are projected at 3.0 °C compared with 1.5 °C. In unprotected areas, the depth of flooding is projected to increase by approximately 50% to 0.21–0.27 m, whilst the average area inundated increases 2.5 times (from 5 to 13% of the region) in the same temperature frame. The greatest area of land flooded is projected in the central and north-east regions. In contrast, lower flood depths, less land area flooded and fewer people are projected in the poldered west of the region. Over multi-centennial timescales, climate change mitigation and controlled sedimentation to maintain relative delta height are key to a delta’s survival. With slow rates of sea-level rise, adaptation remains possible, but further support is required. Monitoring of sea-level rise and subsidence in deltas is recommended, together with improved datasets of elevation.

     

Understanding global sea levels: past, present and future

The coastal zone has changed profoundly during the 20th century and, as a result, society is becoming increasingly vulnerable to the impact of sea-level rise and variability. This demands improved understanding to facilitate appropriate planning to minimise potential losses. With this in mind, the World Climate Research Programme organised a workshop (held in June 2006) to document current understanding and to identify research and observations required to reduce current uncertainties associated with sea-level rise and variability. While sea levels have varied by over 120 m during glacial/interglacial cycles, there has been little net rise over the past several millennia until the 19th century and early 20th century, when geological and tide-gauge data indicate an increase in the rate of sea-level rise. Recent satellite-altimeter data and tide-gauge data have indicated that sea levels are now rising at over 3 mm year⁻¹. The major contributions to 20th and 21st century sea-level rise are thought to be a result of ocean thermal expansion and the melting of glaciers and ice caps. Ice sheets are thought to have been a minor contributor to 20th century sea-level rise, but are potentially the largest contributor in the longer term. Sea levels are currently rising at the upper limit of the projections of the Third Assessment Report of the Intergovernmental Panel on Climate Change (TAR IPCC), and there is increasing concern of potentially large ice-sheet contributions during the 21st century and beyond, particularly if greenhouse gas emissions continue unabated. A suite of ongoing satellite and in situ observational activities need to be sustained and new activities supported. To the extent that we are able to sustain these observations, research programmes utilising the resulting data should be able to significantly improve our understanding and narrow projections of future sea-level rise and variability.     

基于STIRPAT模型的甘肃省环境影响分析

能源短缺已成为全球资源环境的主要问题之一，辩明人类活动各因素对能源消费的影响程度，并据此制定和实施可持续的能源消费政策是当前的研究热点。以STIRPAT模型为分析工具，以甘肃省1991～2009年能源消费总量为环境影响指标，分解了人文因素对环境影响的作用大小。结果表明，富裕程度的提高和城市化进程的推进都能够加剧环境的恶化，而且城市化对环境影响的弹性系数是富裕对环境影响弹性系数的278倍。在观测数据范围内，尚未出现环境Kuznets曲线的拐点，仍然处于曲线的上升段。居民消费结构的多样化有利于降低能源消费，其对环境影响的抑制作用略低于富裕对环境影响的加剧作用。最后讨论了STIRPAT模型的优缺点，并指出甘肃省主要相关因子对环境影响的作用机理还有待更深一步的研究