气候变化国家评估报告（II）：气候变化的影响与适应

已经观测到的气候变化影响是显著的、多方面的。各个领域和地区都存在有利和不利影响,但以不利影响为主,未来的气候变暖将会对中国的生态系统、农业以及水资源等部门和沿海地区产生重大的不利影响。采取适应措施可以减轻气候变化的不利影响,应将适应气候变化的行动逐步纳入国民经济和社会发展的中长期规划中。由于我国科学研究的相对不足和科学认识能力的局限,目前的气候变化影响评估方法和结果还存在很大的不确定性。应当加强区域适应气候变化的案例研究、扩大研究领域、加强极端天气、气候事件影响的研究,以降低影响评估的不确定性,并提出切实可行的适应对策。     

气候变化对跨境水资源影响的适应性评估与管理框架

气候变化增加了国际河流冲突的可能性,加强跨境水资源适应性管理是流域国可持续发展的必然选择。梳理了适应性相关研究的国内外最新进展,认识到适应性管理的关键问题是要发展一套科学评估未来气候变化影响及适应性策略的程序。通过论述气候变化下跨境水资源的适应性评估与管理框架,提出一个气候变化影响决策评估工具,包括信息收集、需求分析、对策分析、综合评估以及实施与调控5个阶段。该项研究将适应性管理与气候变化、定量化脆弱性及适应能力关联评价、成本效益分析、多目标优化决策和动态调控等有机结合,为从跨界层面制定具有针对性的适应性管理对策提供了思路与方法,有利于促进国际河流流域可持续发展。     

Climate change and road freight safety: a multidisciplinary exploration

The freight and logistics sector is of significant importance as an enabler and driver of the global economy, but it is also inherently vulnerable to hazardous weather. Despite this, there is currently no quantitative assessment of how climate change may affect the sector. This paper applies multidisciplinary climate change impact assessment tools and conceptual frameworks to the road freight sector of Great Britain in order to identify potential future weather-related safety issues. Relationships between weather and freight accidents are determined using road accident data and meteorological observations, which are then used with climate change scenarios to arrive at projections of possible impacts across the regions of Great Britain. Included in the study are industry perceptions of future trends within the sector and wider economy which many affect freight’s exposure and sensitivity to weather. These are elicited through interviews and an iterative expert Delphi study. Hence, unlike many other climate change impact assessments, this innovative study takes into account the potentially significant impact of socio-economic change (including institutional and operational). The results show that summer precipitation and winter ice-related accidents are likely to decrease across most of the country, whereas winter rain-related accidents are projected to increase. However, it is postulated that some of the impacts of climate change will be modified by reflexive behavioural change on the part of the driver and either institutional adaptation or complacency on the part of the road authorities. The paper concludes by framing the study in a range of future scenarios outlining how the socio-economic environment could influence the road transport network and how it is used, modifying the impact of climate change.     

可计算一般均衡框架下的气候变化经济影响综合评估

气候变化是21世纪人类面临的重大挑战之一,并对自然系统和社会经济系统造成了各种负面影响。对气候变化的影响进行经济评估是气候变化研究中的重要问题。而可计算一般均衡框架下的综合评估模型（CGE_IAMs）是评估气候变化经济影响的有效手段之一,文中对气候变化影响经济评估的主要CGE_IAMs进行了文献调研,并对这些模型进行了比较分析。研究表明不同模型在温室气体排放、气候参数的处理方式以及气候影响的引入机制等方面有着较大区别,因而各模型对气候变化影响的经济评估结果也有一定的差异。此外,当前CGE_IAMs在评估气候变化经济影响时存在支撑数据未及时更新、方法不细致以及评估不全面等问题。未来该领域的相关研究应该更加关注于模型与支撑数据的精细化和开源化,此外还应加强CGE_IAMs中经济模块与复杂气候模式的耦合。     

A new scenario framework for climate change research: the concept of shared climate policy assumptions

The new scenario framework facilitates the coupling of multiple socioeconomic reference pathways with climate model products using the representative concentration pathways. This will allow for improved assessment of climate impacts, adaptation and mitigation. Assumptions about climate policy play a major role in linking socioeconomic futures with forcing and climate outcomes. The paper presents the concept of shared climate policy assumptions as an important element of the new scenario framework. Shared climate policy assumptions capture key policy attributes such as the goals, instruments and obstacles of mitigation and adaptation measures, and introduce an important additional dimension to the scenario matrix architecture. They can be used to improve the comparability of scenarios in the scenario matrix. Shared climate policy assumptions should be designed to be policy relevant, and as a set to be broad enough to allow a comprehensive exploration of the climate change scenario space.     

Projecting and hindcasting potential evaporation for the UK between 1950 and 2099

Evaporation estimation is important for the assessment of a wide range of potential impacts of climate change, yet there are significant questions concerning the relevance of alternative methods for climate change studies, and the uncertainty associated with downscaled driving variables. Using principal components analysis, climate variables related to evaporation have been examined; results show significant differences in correlation structures between observed UK data and climate outputs from a Hadley Centre Global Climate Model (HadCM3). Although employing the GCM data directly in the Penman-Monteith combination equation appears to be practical for estimating current potential evaporation, this approach does not project realistic potential evaporation in the 2080s. A local calibration approach is taken to the derivation of an alternative empirical model for estimating potential evaporation based on GCM outputs, using the Generalised Linear Model (GLM) framework. This appears to provide a robust method for impacts assessment. From the GLM projections, the envisaged change in evaporation will be spatially variable across the UK. It is expected that the southern part of the UK will be more sensitive to the change in evaporation than the north. Moreover, in the 2080s, the range (variance) of the monthly potential evaporation appears to change more than the mean.     

Adaptation of agriculture to climate change

Preparing agriculture for adaptation to climate change requires advance knowledge of how climate will change and when. The direct physical and biological impacts on plants and animals must be understood. The indirect impacts on agriculture's resource base of soils, water and genetic resources must also be known. We lack such information now and will, likely, for some time to come. Thus impact assessments for agriculture can only be conjectural at this time. How-ever, guidance can be gotten from an improved understanding of current climatic vulnerabilities of agriculture and its resource base, from application of a realistic range of climate change scenarios to impact assessment, and from consideration of the complexity of current agricultural systems and the range of adaptation techniques and policies now available and likely to be available in the future.     

Implications of simultaneously mitigating and adapting to climate change: initial experiments using GCAM

Most research on future climate change discusses mitigation and impacts/adaptation separately. However, mitigation will have implications for impacts and adaptation. Similarly, impacts and adaptation will affect mitigation. This paper begins to explore these two veins of research simultaneously using an integrated assessment model. We begin by discussing the types of interactions one might expect by impact sector. Then, we develop a numerical experiment in the agriculture sector to illustrate the importance of considering mitigation, impacts, and adaptation at the same time. In our experiment, we find that climate change can reduce crop yields, resulting in an expansion of cropland to feed a growing population and a reduction in bioenergy production. These two effects, in combination, result in an increase in the cost of mitigation.     

Vulnerable or Resilient? A Multi-Scale Assessment of Climate Impacts and Vulnerability in Norway

This paper explores the issue of climate vulnerability in Norway, an affluent country that is generally considered to be resilient to the impacts of climate change. In presenting a multi-scale assessment of climate change impacts and vulnerability in Norway, we show that the concept of vulnerability depends on the scale of analysis. Both exposure and the distribution of climate sensitive sectors vary greatly across scale. So do the underlying social and economic conditions that influence adaptive capacity. These findings question the common notion that climate change may be beneficial for Norway, and that the country can readily adapt to climate change. As scale differences are brought into consideration, vulnerability emerges within some regions, localities, and social groups. To cope with actual and potential changes in climate and climate variability, it will be necessary to acknowledge climate vulnerabilities at the regional and local levels, and to address them accordingly. This multi-scale assessment of impacts and vulnerability in Norway reinforces the importance of scale in global change research.     

What information do policy makers need to develop climate adaptation plans for smallholder farmers? The case of Central America and Mexico

Scientific and technical information can increase the ability of policy makers to make strategic decisions. However, climate change policy is often formulated without significant input from science. We examine whether the availability and accessibility of information related to climate change is a major barrier for policy action on climate change adaptation for smallholder farmers. We also investigate whether scientific information related to climate change is available and used in policy making in Central America and Mexico. Our online survey of 105 decision makers indicated that a lack of scientific and technical information hinders policy makers from developing policies to help smallholder farmers adapt to climate change. Specific needs include information on the impacts of climate change on water availability for agriculture and the areas that are or will be prone to flooding, droughts or landslides. Information about the location of the farmers who are most vulnerable to climate change, the projected temperature and precipitation in agricultural areas and the expected impacts of climate change on crop yields or animal productivity, is also needed. Despite high interest in having scientific information guide policy making, many respondents indicated that policy makers rarely use this information in adaptation planning. In addition to ensuring that relevant information is available to inform policy making, technical and scientific information must be published in venues that are readily accessible for policy makers, easy to understand, and written in a format that is policy-relevant. It is also critical that scientific articles provide specific recommendations for achieving desired policy outcomes.     

Climate change hotspots mapping: what have we learned?

In the past 5 years there has been a proliferation of efforts to map climate change “hotspots” — regions that are particularly vulnerable to current or future climate impacts, and where human security may be at risk. While some are academic exercises, many are produced with the goal of drawing policy maker attention to regions that are particularly susceptible to climate impacts, either to mitigate the risk of humanitarian crises or conflicts or to target adaptation assistance. Hotspots mapping efforts address a range of issues and sectors such as vulnerable populations, humanitarian crises, conflict, agriculture and food security, and water resources. This paper offers a timely assessment of the strengths and weaknesses of current hotspots mapping approaches with the goal of improving future efforts. It also highlights regions that are anticipated, based on combinations of high exposure, high sensitivity and low adaptive capacity, to suffer significant impacts from climate change.     

Climate change: long-term targets and short-term commitments

International negotiations under the UN Framework Convention on Climate Change could take several different approaches to advance future mitigation commitments. Options range from trying to reach consensus on specific long-term atmospheric concentration targets (e.g. 550 ppmv) to simply ignoring this contentious issue and focusing instead on what can be done in the nearer term. This paper argues for a strategy that lies between these two extremes. Internationally agreed threshold levels for certain categories of impacts or of risks posed by climate change could be translated into acceptable levels of atmospheric concentrations. This could help to establish a range of upper limits for global emissions in the medium term that could set the ambition level for negotiations on expanded GHG mitigation commitments. The paper thus considers how physical and socio-economic indicators of climate change impacts might be used to guide the setting of such targets. In an effort to explore the feasibility and implications of low levels of stabilisation, it also quantifies an intermediate global emission target for 2020 that keeps open the option to stabilise at 450 ppmv CO₂ If new efforts to reduce emissions are not forthcoming (e.g. the Kyoto Protocol or similar mitigation efforts fail), there is a significant chance that the option of 450 ppmv CO₂ is out of reach as of 2020. Regardless of the preferred approach to shaping new international commitments on climate change, progress will require improved information on the avoided impacts climate change at different levels of mitigation and careful assessment of mitigation costs.     

Application of the Ricardian Technique to Estimate the Impact of Climate Change on Smallholder Farming in Sri Lanka

This study applies the Ricardian technique to estimate the effect of climate change on the smallholder agriculture sector in Sri Lanka. The main contribution of the paper is the use of household-level data to analyze long-term climate impacts on farm profitability. Household-level data allows us to control for a host of factors such as human and physical capital available to farmers as well as adaptation mechanisms at the farm level. We find that non-climate variables explain about half the variation in net revenues. However, our results suggest that climate change will have a significant impact on smallholder profitability. In particular, reductions in precipitation during key agricultural months can be devastating. At the national level, a change in net revenues of between −23% and +22% is likely depending on the climate change scenario simulated. These impacts will vary considerably across geographic areas from losses of 67% to gains that more than double current net revenues. The largest adverse impacts are anticipated in the dry zones of the North Central region and the dry zones of the South Eastern regions of Sri Lanka. On the other hand, the intermediate and wet zones are likely to benefit, mostly due to the predicted increase in rainfall.     

A conceptual framework for cross-border impacts of climate change

Climate change impacts, adaptation and vulnerability studies tend to confine their attention to impacts and responses within the same geographical region. However, this approach ignores cross-border climate change impacts that occur remotely from the location of their initial impact and that may severely disrupt societies and livelihoods. We propose a conceptual framework and accompanying nomenclature for describing and analysing such cross-border impacts. The conceptual framework distinguishes an initial impact that is caused by a climate trigger within a specific region. Downstream consequences of that impact propagate through an impact transmission system while adaptation responses to deal with the impact propagate through a response transmission system. A key to understanding cross-border impacts and responses is a recognition of different types of climate triggers, categories of cross-border impacts, the scales and dynamics of impact transmission, the targets and dynamics of responses and the socio-economic and environmental context that also encompasses factors and processes unrelated to climate change. These insights can then provide a basis for identifying relevant causal relationships. We apply the framework to the floods that affected industrial production in Thailand in 2011, and to projected Arctic sea ice decline, and demonstrate that the framework can usefully capture the complex system dynamics of cross-border climate impacts. It also provides a useful mechanism to identify and understand adaptation strategies and their potential consequences in the wider context of resilience planning. The cross-border dimensions of climate impacts could become increasingly important as climate changes intensify. We conclude that our framework will allow for these to be properly accounted for, help to identify new areas of empirical and model-based research and thereby support climate risk management.     

Firm relocation as adaptive response to climate change and weather extremes

Growing scientific evidence suggests that human-induced climate change will bring about large-scale environmental changes such as sea-level rise and coastal flooding, extreme weather events and agricultural disruptions. The speed and extent of these changes and the expected impacts on social and corresponding economic and industrial systems are now moving to the forefront of debates. In this paper, we argue that climate change will lead to significant disruptions to firms which might ultimately create the necessity of a geographical shift of firm and industrial activities away from regions highly affected by climate change. Such a shift might become necessary due to (1) direct disruptions through climate change impacts on firm operations, for instance through droughts, floods, or sea level rise, and due to (2) disruptions in a firm's supplier, buyer or resource base that lead to flow-on effects and adverse consequences for a firm. We propose a framework for integrating firm relocation decisions into firm adaptive responses to climate change. The framework consists of three assessment steps: the level of risk from climate change impacts at a firm's location, the feasibility of relocation, and associated costs and benefits. We apply the framework to two case examples. The first case of electricity distribution firms in Victoria/Australia illustrates how the relocation (undergrounding) of cables could decrease the vulnerability of distribution networks to bushfires and the risk of electricity-caused fires, but would require significant investments. The second case of firms in the Australian pastoral industry points to geographic diversification of pastoral land holdings as possible adaptation option, but also to constraints in form of availability of suitable properties, ties to local communities, and adverse impacts on biodiversity. Implications for adaptation research and practice are outlined.     

气候变化国家评估报告(Ⅱ):气候变化的影响与适应

Significant and various impacts of climate change have been observed in China, showing both positive and adverse effects, dominantly the latter, in different sectors and regions. It is very likely that future climate change would cause significant adverse impacts on the ecosystems, agriculture, water resources, and coastal zones in China. Adoption of adaptive measures to climate change can alleviate the adverse impact, therefore such measures should be incorporated into the medium-and long-term national economic and social development plans. Because China has done relatively limited research on impact assessment and our understanding of climate change is incomplete, the current impact assessment methodologies used and results obtained contain many uncertainties. To reduce the uncertainties and develop effective and practical climate change adaptive measures in China, it is necessary to emphasize regional case studies on adaptive measures, enlarge the scope of climate change research, and strengthen the assessment of the impacts resulted from extreme weather/climate events.     

Linkages between climate change and sustainable development

Climate change does not yet feature prominently within the environmental or economic policy agendas of developing countries. Yet evidence shows that some of the most adverse effects of climate change will be in developing countries, where populations are most vulnerable and least likely to easily adapt to climate change, and that climate change will affect the potential for development in these countries. Some synergies already exist between climate change policies and the sustainable development agenda in developing countries, such as energy efficiency, renewable energy, transport and sustainable land-use policies. Despite limited attention from policy-makers to date, climate change policies could have significant ancillary benefits for the local environment. The reverse is also true as local and national policies to address congestion, air quality, access to energy services and energy diversity may also limit GHG emissions. Nevertheless there could be significant trade-offs associated with deeper levels of mitigation in some countries, for example where developing countries are dependent on indigenous coal and may be required to switch to cleaner yet more expensive fuels to limit emissions. The distributional impacts of such policies are an important determinant of their feasibility and need to be considered up-front. It follows that future agreements on mitigation and adaptation under the convention will need to recognise the diverse situations of developing countries with respect to their level of economic development, their vulnerability to climate change and their ability to adapt or mitigate. Recognition of how climate change is likely to influence other development priorities may be a first step toward building cost-effective strategies and integrated, institutional capacity in developing countries to respond to climate change. Opportunities may also exist in developing countries to use regional economic organisations to assist in the design of integrated responses and to exploit synergies between climate change and other policies such as those designed to combat desertification and preserve biodiversity.     

Climate change and adaptation: an integrated framework linking social and physical aspects in poorly-gauged regions

Various frameworks related to climate change and adaptations that have been developed to date have notable benefits as well as significant limitations. It is not always practical to implement advanced climate change frameworks in situations with limited data availability. Social aspects, such as people’s experience and perception, are often under-prioritized. Therefore, this study introduces an integrated framework linking social and physical aspects of climate change to assess its impacts on water resources and to evaluate differing adaptation options in poorly gauged basins. A case study of the Kali Gandaki River Basin (KGRB) in western Nepal is presented to demonstrate the applicability of this framework. Results of the study show that people of the mountainous Mustang district in the KGRB have perceived climate change or climate variability, its impacts on water resources, as well as other water-related issues and potential adaptations or responses. Furthermore, evaluation of people’s perception using available physical data confirms the increase in temperature and average annual discharge in the Kali Gandaki River as well as poor water use, as a major problem at all levels in the basin. Despite increasing water availability, a concurrent increase in water use is difficult due to topographic constraints on irrigation development. However, the impacts of climate change are particularly severe in Mustang, owing to the fact that a large proportion of the population depends on a climate-sensitive livelihood like agriculture. Therefore, various adaptation options are identified in the agricultural sector, and one relevant option is further evaluated. The framework developed in this study has the potential to be further applied to other poorly gauged basins.     

The economics of climate change impacts and policy benefits at city scale: a conceptual framework

Cities are particularly vulnerable to climate change and climate extremes in part because they concentrate many activities, people and wealth in limited areas. As a result they represent an important scale for assessment and understanding of climate change impacts. This paper provides a conceptual and methodological framework for urban economic impact assessment of climate change. The focus of the paper is on model-based analysis of future scenarios, including a framing of uncertainty for these projections, as one valuable input into the decision-making process. The paper highlights the main assessment difficulties, methods and tools, and selected examples across these areas. A number of challenges are unique to climate change impact assessment and others are unique to the problem of working at local scales. The paper also identifies the need for additional research, including the need for more integrated and systemic approaches to address climate change as a part of the urban development challenge as well as the need to assess the economic impacts of climate change and response policy at local scale.     

Impact assessments and policy responses to sea-level rise in three US states: An exploration of human-dimension uncertainties

Uncertainties in the human dimensions of global change deeply affect the assessment and responses to climate change impacts such as sea-level rise (SLR). This paper explores the uncertainties in the assessment process and in state-level policy and management responses of three US states to SLR. The findings reveal important political, economic, managerial, and social factors that enable or constrain SLR responses; question disasters as policy windows; and uncover new policy opportunities in the history of state coastal policies. Results suggest that a more realistic, and maybe more useful picture of climate change impacts will emerge if assessments take more seriously the locally embedded realities and constraints that affect individual decision-makers’ and communal responses to climate change.