Future demographic change and its interactions with migration and climate change

This paper examines global demographic change as a driver of migration within the context of anticipated climate change. It begins by briefly considering some theoretical formulations which relate demographic change and migration. It then considers evolving global demographic trends and discusses some of their potential impacts upon migration. It is shown that there is a close spatial coincidence between demographic and climate change “hotspots” that will influence migration in complex ways. It then turns to the complex interaction between demographic change, environmental change and migration, both in the past and potential developments in the future. It concludes with a discussion of the potential impacts of future trends and their policy implications.     

Land-use and climate change within assessments of biodiversity change: A review

Projected changes in biodiversity are likely inadequately estimated when climate and land-use change effects are examined in isolation. A review of studies of the effects of these drivers singly and in combination highlights little discussed complexities in revising these estimates. In addition to considering interactions, different characterisations of climate change, land-use change and biodiversity greatly influence estimates. Habitat loss leading to decreased species richness is the most common land-use change and biodiversity relationship considered with less attention being given to other land-use changes (e.g. other conversions, fragmentation, different management intensities) and biodiversity characterisations and responses (e.g. selected groups of species, increased species richness). Characterisations of more complex relationships between climate change, land-use change and biodiversity however are currently limited by a lack of process understanding, data availability and inherent scenarios uncertainties.     

Index of direction change of zonally averaged wind and change of season

In this paper, a Wind Direction Change Index (WI), which can describe four-dimensional spatiotemporal changes of the atmospheric circulation objectively and quantitatively, is defined to study its evolution and seasonal variation. The first four modes can be obtained by EOF expansion of the zonally averaged WI. The first mode reveals the basic spatial distribution of the annually averaged WI. The second mode reflects the quasi-harmonic parts of the WI deviations. Tropical, subtropical and extratropical monsoon areas can be clearly reflected by this mode. The third mode reflects the non-harmonic parts of the WI deviations. It shows the so-called February reverse in stratospheric atmosphere as well as the asymmetric seasonal changes from spring to fall and from fall to spring due to both the land-sea distribution contrast between the Northern and Southern Hemispheres and the nonlinear effect of atmospheric and ocean fluids. The fourth mode reveals the northward advancing of the global reversed wind fields from spring to summer and their southward withdrawal from summer to autumn.     

Antarctica and global change

The Antarctic region of the globe is of special importance for a wide range of studies of global change. The IGBP research activities needing special focus for global change should be multidisciplinary, should involve both the geosphere and the biosphere, and should be of global as well as local interest. There are a number of important Antarctic research topics which fit these criteria.A decrease of Antarctic sea ice has a positive feedback on global warming. Reduction in the sea ice also impacts on deep ocean circulation and can give a positive feedback to the increase of atmospheric carbon dioxide by the reduction of a deep ocean sink. Changes in the mass balance of the Antarctic ice sheet impact on global sea level. A unique historic record of past climate and global environmental changes is being obtained from deep core drilling in the Antarctic ice sheet. Decreases of stratospheric ozone are most pronounced over the Antarctic in spring. The impact of increases in ultraviolet radiation on the biosphere can be studied in the Antarctic as a precurser to possible changes developing elsewhere around the globe. Changes in the atmosphere and ocean circulations resulting from the decrease in Antarctic sea ice cover can have important effects on ocean surface temperatures which impact on the climates of the continents.These topics are discussed briefly and a number of Antarctic research areas are highlighted which build on existing or planned international programmes and which can make critical contributions to multidisciplinary studies of global change.     

Security and climate change

Despite it being the most studied and arguably most profound of global environmental change problems, there is relatively little research that explores climate change as a security issue. This paper systematically explores the range of possible connections between climate change and security, including national security considerations, human security concerns, military roles, and a discussion of the widely held assumption that climate change may trigger violent conflict. The paper explains the ways in which climate change is a security issue. It includes in its discussion issues to do with both mitigation and adaptation of climate change.     

Learning and climate change

Abstract

Learning—i.e. the acquisition of new information that leads to changes in our assessment of uncertainty—plays a prominent role in the international climate policy debate. For example, the view that we should postpone actions until we know more continues to be influential. The latest work on learning and climate change includes new theoretical models, better informed simulations of how learning affects the optimal timing of emissions reductions, analyses of how new information could affect the prospects for reaching and maintaining political agreements and for adapting to climate change, and explorations of how learning could lead us astray rather than closer to the truth. Despite the diversity of this new work, a clear consensus on a central point is that the prospect of learning does not support the postponement of emissions reductions today.     

Global socio-economic and climate change mitigation scenarios through the lens of structural change

This paper analyses structural change in the economy as a key but largely unexplored aspect of global socio-economic and climate change mitigation scenarios. Structural change can actually drive energy and land use as much as economic growth and influence mitigation opportunities and barriers. Conversely, stringent climate policy is bound to induce specific structural and socio-economic transformations that are still insufficiently understood. We introduce Multi-Sectoral macroeconomic Integrated Assessment Models as tools to capture the key drivers of structural change and we conduct a multi-model study to assess main structural effects – changes of the sectoral composition and intensity of trade of global and regional economies – in a baseline and 2°C policy scenario by 2050. First, the range of baseline projections across models, for which we identify the main drivers, illustrates the uncertainty on future economic pathways – in emerging economies especially – and inform on plausible alternative futures with implications for energy use and emissions. Second, in all models, climate policy in the 2°C scenario imposes only a second-order impact on the economic structure at the macro-sectoral level – agriculture, manufacturing and services - compared to changes modelled in the baseline. However, this hides more radical changes for individual industries – within the energy sector especially. The study, which adopts a top-down framing of global structural change, represents a starting point to kick-start a conversation and propose a new research agenda seeking to improve understanding of the structural change effects in socio-economic and mitigation scenarios, and better inform policy assessments.     

气候变化条件下雅砻江流域未来径流变化趋势研究

雅砻江为我国重要的水电基地,未来气候变化条件下流域径流变化将直接影响雅砻江梯级水库群运行安全和发电调度,因此研究气候变化对雅砻江流域径流的影响十分必要。首先建立了流域月尺度的SWAT模型,然后使用统计降尺度模型（SDSM）模拟未来2006—2100年流域内各站点的气象数据,最后使用流域SWAT模型对未来2006—2100年月径流进行模拟。结果表明,未来雅砻江流域径流呈上升趋势,且增幅随着辐射强迫的增加同步增大,RCP2.6、RCP4.5、RCP8.5这3种典型浓度路径下年平均径流增幅分别为8.9%、12.5%、16.7%,且2020S（2006—2035年)、2050S（2036—2065年)、2080S（2066—2100年）这3个时期年径流量呈现不同的变化趋势,其中RCP2.6浓度路径下为先逐步增加达到峰值后略有减少,RCP4.5浓度路径下为先逐步增加达到峰值后趋于稳定,RCP8.5浓度路径下为持续增加。流域径流年内分配方面,3种典型浓度路径下汛期径流占全年比例在2020S、2050S、2080S这3个时期均为先降后升趋势,整个预测期总体为降低趋势,RCP2.6、RCP4.5及RCP8.5这3种浓度路径下整个预测期的均值分别由基准期的75.9%降低为72.9%、72.0%、71.2%。径流增加会对流域洪水特性产生较大影响,为此应该修正流域设计洪水计算结果和调整防洪调度方案,以降低雅砻江流域梯级水库群因气候变化而产生的运行风险,并提高发电调度效率。     

Reconceptualising adaptation to climate change as part of pathways of change and response

The need to adapt to climate change is now widely recognised as evidence of its impacts on social and natural systems grows and greenhouse gas emissions continue unabated. Yet efforts to adapt to climate change, as reported in the literature over the last decade and in selected case studies, have not led to substantial rates of implementation of adaptation actions despite substantial investments in adaptation science. Moreover, implemented actions have been mostly incremental and focused on proximate causes; there are far fewer reports of more systemic or transformative actions. We found that the nature and effectiveness of responses was strongly influenced by framing. Recent decision-oriented approaches that aim to overcome this situation are framed within a “pathways” metaphor to emphasise the need for robust decision making within adaptive processes in the face of uncertainty and inter-temporal complexity. However, to date, such “adaptation pathways” approaches have mostly focused on contexts with clearly identified decision-makers and unambiguous goals; as a result, they generally assume prevailing governance regimes are conducive for adaptation and hence constrain responses to proximate causes of vulnerability. In this paper, we explore a broader conceptualisation of “adaptation pathways” that draws on ‘pathways thinking’ in the sustainable development domain to consider the implications of path dependency, interactions between adaptation plans, vested interests and global change, and situations where values, interests, or institutions constrain societal responses to change. This re-conceptualisation of adaptation pathways aims to inform decision makers about integrating incremental actions on proximate causes with the transformative aspects of societal change. Case studies illustrate what this might entail. The paper ends with a call for further exploration of theory, methods and procedures to operationalise this broader conceptualisation of adaptation.     

Triggering transformative change: a development path approach to climate change response in communities

While climate change action plans are becoming more common, it is still unclear whether communities have the capacity, tools, and targets in place to trigger the transformative levels of change required to build fundamentally low-carbon, resilient, healthy communities. Evidence increasingly supports the finding that this transformation is not triggered by climate policy alone, but rather is shaped by a broad array of decisions and practices that are rooted in underlying patterns of development. Even so, these findings have rarely penetrated the domain of practice, which often remains squarely focused on a relatively narrow set of climate-specific policies. This article builds a conceptual framework for understanding the dynamics of community-level development path transformations that may both dramatically reduce GHG emissions and significantly enhance community resilience. This framework illuminates eight critical enablers of innovation on climate change, each of which is illustrated by compelling examples of community-level experimentation on climate change across the province of British Columbia, Canada. It is concluded that community-based climate (or sustainability) policy might be more likely to trigger development path shifts if it employs a longer time horizon, recognition of adaptability and feedbacks, integrated decision making, and systems thinking.     

Scepticism and uncertainty about climate change: Dimensions, determinants and change over time

While scientific consensus and political and media messages appear to be increasingly certain, public attitudes and action towards the issue do not appear to be following suit. Popular and academic debate often assumes this is due to ignorance or misunderstanding on the part of the public, but some studies have suggested political beliefs and values may play a more important role in determining belief versus scepticism about climate change. The current research used two representative postal surveys of the UK public to: measure scepticism and uncertainty about climate change; determine how scepticism varies according to individual characteristics, knowledge and values; and examine how scepticism has changed over time. Findings show denial of climate change is less common than the perception that the issue has been exaggerated. Scepticism was found to be strongly determined by individuals’ environmental and political values (and indirectly by age, gender, location and lifestyle) rather than by education or knowledge. Between 2003 and 2008, public uncertainty about climate change has remained remarkably constant, although belief that claims about the issue are exaggerated has doubled over that period. These results are interpreted with reference to psychological concepts of motivated reasoning, confirmation bias and ‘finite pool of worry’. Implications for communication and policy are discussed.     

下垫面改变导致局地气候变化的理论分析

运用气柱内辐射，相变，对流间的平衡及地表能量平衡条件研究了由于地表状况改变，即植被退化所造成的局地气候变化，结果表明地表反射率的加大及地面热通量的变化造成中国北方降水量的减少和温度的增加。粗糙度的减少也能造成降水量减少和温度增加，这些结果与数值模拟一致。考虑平流作用以后，上述特征不变，但降水及温度改变量发生变化。在全球增暖背景下，降水减少和温度增加要更剧烈些。     

Racing climate change: Collaboration and conflict in California's global climate change policy arena

Media accounts routinely refer to California's Assembly Bill 32 (AB 32), the Global Warming Solutions Act of 2006, as “landmark” climate change legislation. On its surface, this label is an accurate reflection of the state's forward-thinking stance across many environmental issues including pesticides, toxic substances, solid waste, and air quality. For all its promise, however, AB 32 can also be considered a low point in the landscape of conflict between state environmental regulators and California's environmental justice movement. While the legislation included several provisions to address the procedural and distributive dimensions of environmental justice, the implementation of AB 32 has been marked by heated conflict. The most intense conflicts over AB 32 revolve around the primacy of market mechanisms such as “cap and trade.” This article examines the drivers and the manifestations of these dynamics of collaboration and conflict between environmental justice advocates and state regulators, and pays particular attention to the scalar and racialized quality of the neoliberal discourse. The contentiousness of climate change politics in California offers scholars and practitioners around the world a cautionary tale of how the best intentions for integrating environmental justice principles into climate change policy do not necessarily translate into implementation and how underlying racialized fractures can upend collaboration between state and social movement actors.     

Human control of climate change

The use of analogies and repeated feedback might help people learn about the dynamics of climate change. In this paper, we study the influence of repeated feedback on the control of a carbon-dioxide (CO₂) concentration to a goal level in a Dynamic Climate Change Simulator (DCCS) using the “bathtub” analogy. DCCS is a simplification of the complex climate system into its essential elements: CO₂ concentration (stock); man-made CO₂ emissions (inflow); and natural CO₂ removal or absorption in the atmosphere (outflow). In a laboratory experiment involving DCCS, we manipulated feedback delays in two ways: the frequency of emission decisions and the rate of CO₂ absorption from the atmosphere (climate dynamics). Our results revealed that participants’ ability to control the CO₂ concentration generally remained poor even in conditions where they were allowed to revise their emission decisions frequently (i.e., every 2?years) and where the climate dynamics were rapid (i.e., 1.6% of CO₂ concentration was removed every year). Participants’ control of the concentration only improved with repeated feedback in conditions of lesser feedback delay. Moreover, the delay due to climate dynamics had a greater effect on participants’ control than the delay due to emission decisions frequency. We provide future research directions and highlight the potential of using simulations like DCCS to help people learn about dynamics of Earth’s climate.