On the relation between ENSO and global climate change

Summary Two lines of research into climate change and El Niño/Southern Oscillation (ENSO) converge on the conclusion that changes in ENSO statistics occur as a response to global climate (temperature) fluctuations. One approach focuses on the statistics of temperature fluctuations interpreted within the framework of random walks. The second is based on the discovery of correlation between the recurrence frequency of El Niño and temperature change, while developing physical arguments to explain several phenomena associated with changes in El Niño frequency. Consideration of both perspectives leads to greater confidence in, and guidance for, the physical interpretation of the relationship between ENSO and global climate change. Topics considered include global dynamics of ENSO, ENSO triggers, and climate prediction and predictability.Revised November 14, 2002; accepted November 28, 2002 Published online: June 12, 2003     

Enhancing the relevance of Shared Socioeconomic Pathways for climate change impacts,adaptation and vulnerability research

This paper discusses the role and relevance of the shared socioeconomic pathways (SSPs) and the new scenarios that combine SSPs with representative concentration pathways (RCPs) for climate change impacts, adaptation, and vulnerability (IAV) research. It first provides an overview of uses of social–environmental scenarios in IAV studies and identifies the main shortcomings of earlier such scenarios. Second, the paper elaborates on two aspects of the SSPs and new scenarios that would improve their usefulness for IAV studies compared to earlier scenario sets: (i) enhancing their applicability while retaining coherence across spatial scales, and (ii) adding indicators of importance for projecting vulnerability. The paper therefore presents an agenda for future research, recommending that SSPs incorporate not only the standard variables of population and gross domestic product, but also indicators such as income distribution, spatial population, human health and governance.     

Weaponizing vulnerability to climate change

As scores of climate change adaptation measures are implemented around the world, there have been growing calls among academics and practitioners to also address the processes that underpin human vulnerability to climate change. However, there is mounting evidence that adaptation and vulnerability are linked, such that ostensibly adaptive responses can have negative consequences and augment people’s vulnerability. We analyzed several climate change responses at various scales and developed a typology of five discrete but related modes by which the vulnerability of already vulnerable populations is being [re]produced. Crucially, this work suggests that for at least one of these modes, the vulnerability of other groups is perversely inverted, such that relatively secure populations perceive themselves to be at risk. The cases we present illustrate that people’s vulnerability is being used against them, or put another way, is being weaponized―exacerbating their precarity by excluding them from much needed and due assistance, while directing resources instead to bolstering the well-being of those already well-positioned to respond to climate threats. Our typology provides a theoretical intervention by illustrating how climate vulnerability and security are co-produced, as well as a practical tool to help decision makers to adopt more just and equitable climate policies.     

气候变化与海洋生态系统：影响、适应和脆弱性——IPCC AR6 WGⅡ报告之解读

IPCC第六次评估报告(AR6)第二工作组报告第三章开展了气候变化对海洋的影响和风险,以及生态系统及其服务功能、脆弱性和适应评估。AR6明确指出,人为气候变化已经并将继续显著地改变全球和区域海洋的气候影响驱动因子,包括海温升高、海平面上升、海洋酸化和缺氧,以及营养盐浓度变化等海洋物理和化学因子。例如,20世纪80年代以来全球海洋热浪发生的频率已增加了1倍,到21世纪末期可能增加4～8倍。气候影响驱动因子的变化已经对海洋和海岸带生态系统造成了广泛而深远的影响:1)海洋变暖使得海洋物种自1950年代以来以(59.2±15.5) km/(10 a)的速率向极地方向迁移,导致热带海域生物量减少,中纬度海区热带化,极地和亚极地海区浮游植物生长期提前;2)频繁发生的海洋热浪事件已经接近甚至超过了某些海洋生物的耐受极限或其气候临界点,如暖水珊瑚的大规模白化、死亡,海草和大型海藻的大面积消失;3)海洋变暖、缺氧和酸化使得河口区生物群落结构改变,赤潮等有害藻华事件频发,近海和大洋浮游植物生物量和初级生产力下降;4)海平面上升导致海岸带红树林、盐沼和海草床等生态系统的退化;5)未来全球海洋生态系统面临的风险将不断加剧,尤其是在热带和北冰洋海区。其中,当全球升温1.5℃时(最快到21世纪40年代,SSP5-8.5情景),暖水珊瑚礁预计将减少70％～90％;当升温2℃时,几乎所有的(>99％)暖水珊瑚礁将会消失。目前人类社会采取的一些措施(如建立海洋保护区和红树林生态修复)已越来越不能应对日益增长的气候风险,迫切需要发展变革性的行动措施,推动海洋生态系统恢复力的发展,并需尽快采取强有力的减排措施以减缓全球变暖的影响。     

Assessing climate change impacts in the European north

Global climate change and its regional manifestation will result in significant impacts in the European North. However, in order to determine the consequences of such impacts, a holistic, integrated assessment is needed. This paper sets the stage for the remainder of this volume by describing an attempt to derive such an assessment for the Barents Sea Region through the EU-funded BALANCE project. The paper explains some of the major methodologies employed in the study. It also provides insight into major results obtained and attempts to answer a number of overarching questions. It will be shown that climate change does present a significant threat to environmental and societal integrity in the study region. However, it will also be shown that stakeholders regard other drivers of future changes (economical, political developments) at least as equally important for their personal lives.     

Virtue and vulnerability: Discourses on women, gender and climate change

In the limited literature on gender and climate change, two themes predominate - women as vulnerable or virtuous in relation to the environment. Two viewpoints become obvious: women in the South will be affected more by climate change than men in those countries and that men in the North pollute more than women. The debates are structured in specific ways in the North and the South and the discussion in the article focuses largely on examples from Sweden and India. The article traces the lineage of the arguments to the women, environment and development discussions, examining how they recur in new forms in climate debates. Questioning assumptions about women's vulnerability and virtuousness, it highlights how a focus on women's vulnerability or virtuousness can deflect attention from inequalities in decision-making. By reiterating statements about poor women in the South and the pro-environmental women of the North, these assumptions reinforce North-South biases. Generalizations about women's vulnerability and virtuousness can lead to an increase in women's responsibility without corresponding rewards. There is need to contextualise debates on climate change to enable action and to respond effectively to its adverse effects in particular places.     

气候变化影响适应和脆弱性评估报告进展：IPCC AR5到AR6的新认知

IPCC第六次评估报告第二工作组(IPCC AR6 WGⅡ)重点关注气候变化的影响、风险、适应性和脆弱性。报告以最新的数据、翔实的证据、多元的方法定量评估了气候变化对自然和人类系统的影响。相比于AR5,AR6 WGⅡ取得了以下进展:1)内容上明确了气候变化的影响归因于人为气候强迫、非气候因子作用和天气敏感性识别等三类;气候变化带来的127个关键风险将变得广泛、普遍或不可逆转,将全球变暖限制在1.5℃,可大大减少气候变化对自然和人类系统的损失和破坏,指出来适应转型的重要性;2)在评估方法上,AR6采用了最新的SSPs和RCPs组合的SSPs情景,综合性更强;3) AR6对风险和解决方案的关注有所增加,并在AR5的基础上明确了5个“关注理由(RFCs)”的关键风险面临的风险水平将在较低的全球变暖水平上变为高到极高;4) AR6明确了气候行动的紧迫性,将适应和减缓相结合以支持气候恢复力(CRD)发展,指出了立即行动以应对气候风险的重要性和紧迫性。     

Classifying knowledge on climate change impacts, adaptation, and vulnerability in Europe for informing adaptation research and decision-making: A conceptual meta-analysis

Knowledge on climate change impacts, adaptation, and vulnerability is fragmented, because it is found in disparate case studies which use inconsistent terminology and focus on distinct aspects relevant to adaptation. While large-scale syntheses such as the Assessment Reports of the Intergovernmental Panel on Climate Change provide a high level overview and are useful for international decision-making, there is a need for systematic and flexible access to this research-based knowledge in order to aid future adaptation research and decision-making. Against this background, we present a ‘conceptual’ meta-analysis, a novel approach to meta-analyse studies on climate change impacts, adaptation, and vulnerability in Europe. The meta-analysis results in a classification scheme for relating the diverse studies. This scheme consists of (i) a classification of studies according to the type of adaptation-relevant results they produce and (ii) a hierarchical classification of the regional and thematic context of studies. The implementation of this scheme, for example in the form of a database, overcomes some of the identified gaps of current adaptation knowledge representation. We furthermore present a quantitative analysis of the classified studies that exemplifies how the developed classification scheme can be applied to get a systematic and quantitative overview of the knowledge they contain. Thus, the conceptual meta-analysis and the classification scheme represent a first step towards a systematisation of knowledge on climate change impacts, adaptation, and vulnerability and may be seen as a useful complement to qualitative literature reviews.     

Operationalizing longitudinal approaches to climate change vulnerability assessment

The past decade has seen a proliferation of community-scale climate change vulnerability assessments globally. Much of this work has employed frameworks informed by scholarship in the vulnerability field, which draws upon interviews with community members to identify and characterize climatic risks and adaptive responses. This scholarship has developed a baseline understanding of vulnerability in specific places and industries at particular times. However, given the dynamic nature of vulnerability new methodologies are needed to generate insights on how climate change is experienced and responded to over time. Longitudinal approaches have long been used in sociology and the health sciences to capture the dynamism of human processes, but their penetration into vulnerability research has been limited. In this article, we describe the application of two longitudinal approaches, cohort and trend studies, in climate change vulnerability assessment by analyzing three case studies from the Arctic where the authors applied these approaches. These case studies highlight how longitudinal approaches can be operationalized to capture the dynamism of vulnerability by identifying climate anomalies and trends, and how adaptations develop over time, including insights on themes such as social learning and adaptive pathways.     

Social,environmental and health vulnerability to climate change in the Brazilian Northeastern Region

A regional vulnerability study in relation to the projected patterns of climate change (A2 and B2 scenarios) was developed for the Brazilian Northeastern region. An aggregated Vulnerability Index was constructed for each of the nine States of the region, based on the following information: population projections; climate-induced migration scenarios; disease trends; desertification rates; economic projections (GDP and employment) and projections for health care costs. The results obtained shall subsidize public policies for the protection of the human population from the projected impacts of regional changes in climate patterns.     

The local impacts of climate change in the Ferlo, Western Sahel

Recent increases in the accuracy of climate models have enhanced the possibilities for analyzing the impacts of climate change on society. This paper explores how the local, economic impacts of climate change can be modeled for a specific eco-region, the Western Sahel. The people in the Sahel are highly dependent on their natural resource base, and these resources are highly vulnerable to climate change, in particular to changes in rainfall. Climate models project substantial changes in rainfall in the Sahel in the coming 50 years, with most models predicting a reduction in rainfall. To connect climate change to changes in ecosystem productivity and local income, we construct an ecological–economic model that incorporates rangeland dynamics, grazing and livestock prices. The model shows that decreased rainfall in the Sahel will considerably reduce local incomes, in particular if combined with increases in rainfall variability. Adaptation to these climate change projections is possible if reductions in rainfall are followed by destocking to reach efficient grazing levels. However, while such a strategy is optimal from the perspective of society, the stocking rate is determined by individual pastoralists that face few incentives to destock.