气候变化科学方面的几个最新认知

IPCC第六次评估报告(AR6)第一工作组报告主要从以下几个方面的进展提升了我们对气候系统变化、气候变化原因以及预估未来气候系统变化等方面的认知,对过去气候变化及其与人类活动的关系有了更加清晰、可靠的认识.综合多重证据评估指出,全球气候正经历着前所未有的变化;包括极端事件在内的归因进展已把人类活动对气候系统影响的认识从...     

A survey of urban climate change experiments in 100 cities

Cities are key sites where climate change is being addressed. Previous research has largely overlooked the multiplicity of climate change responses emerging outside formal contexts of decision-making and led by actors other than municipal governments. Moreover, existing research has largely focused on case studies of climate change mitigation in developed economies. The objective of this paper is to uncover the heterogeneous mix of actors, settings, governance arrangements and technologies involved in the governance of climate change in cities in different parts of the world.The paper focuses on urban climate change governance as a process of experimentation. Climate change experiments are presented here as interventions to try out new ideas and methods in the context of future uncertainties. They serve to understand how interventions work in practice, in new contexts where they are thought of as innovative. To study experimentation, the paper presents evidence from the analysis of a database of 627 urban climate change experiments in a sample of 100 global cities.The analysis suggests that, since 2005, experimentation is a feature of urban responses to climate change across different world regions and multiple sectors. Although experimentation does not appear to be related to particular kinds of urban economic and social conditions, some of its core features are visible. For example, experimentation tends to focus on energy. Also, both social and technical forms of experimentation are visible, but technical experimentation is more common in urban infrastructure systems. While municipal governments have a critical role in climate change experimentation, they often act alongside other actors and in a variety of forms of partnership. These findings point at experimentation as a key tool to open up new political spaces for governing climate change in the city.     

情景预估在气候变化科普中的作用

通过对国内外情景预估模拟展现气候变化前景和极端气象条件下的灾害事件正、反两方面的案例分析,总结情景预估应用的经验和教训,提出充分发挥情景预估辅助作用的思路,并展望未来情景预估与虚拟现实等高科技结合的应用前景。     

Climatic trends and impact of climate change on agriculture in an arid Andean valley

Little is known about climate change and its impacts for the arid coastal and mountainous regions in northern Chile. The Elqui river basin, part of the Norte Chico of Chile between 27oS and 33oS latitude, is located south of the hyper-arid Atacama desert. Despite water scarcity, agricultural development in this region has been enhanced by agronomic practices and the marketing of valuable products. This paper characterizes the actual climate conditions and presents an overview and analyses of past climate variability, and future possible climate trends, emphasizing those relevant to agriculture. Precipitation shows an important decrease during the first decades of the past century. Runoff shows decreasing trends for the first half of the past century and increases for 1960 to 1985. Drought appears to be increasing. Statistical downscaling was accomplished using the Long Ashton Research Station Weather Generator. Both future periods of 2011 to 2030 and 2046–65 showed trends to higher minimum and maximum temperature. The number of hot days (maximum temperature greater than or equal to 30°C) has a strong increasing trend during October to April. Even though the downscaled results for precipitation do not show trends, the continuation of the present trend of low amounts is a concern. We discuss some implications of climatic changes for agriculture and we emphasize the importance of adaptation, especially to deal with water scarcity.     

An overview of decadal climate predictability in a multi-model ensemble by climate model MIROC

Decadal climate predictability is examined in hindcast experiments by a multi-model ensemble using three versions of the coupled atmosphere-ocean model MIROC. In these hindcast experiments, initial conditions are obtained from an anomaly assimilation procedure using the observed oceanic temperature and salinity with prescribed natural and anthropogenic forcings on the basis of the historical data and future emission scenarios in the Intergovernmental Panel of Climate Change. Results of the multi-model ensemble in our hindcast experiments show that predictability of surface air temperature (SAT) anomalies on decadal timescales mostly originates from externally forced variability. Although the predictable component of internally generated variability has considerably smaller SAT variance than that of externally forced variability, ocean subsurface temperature variability has predictive skills over almost a decade, particularly in the North Pacific and the North Atlantic where dominant signals associated with Pacific decadal oscillation (PDO) and the Atlantic multidecadal oscillation (AMO) are observed. Initialization enhances the predictive skills of AMO and PDO indices and slightly improves those of global mean temperature anomalies. Improvement of these predictive skills in the multi-model ensemble is higher than that in a single-model ensemble.     

An analysis of regional climate change in Switzerland

Summary An analysis of daily climatological data covering the period from 1901 to 1992 for four locations in Switzerland (Zurich, Lugano, Davos, and Säntis) has been made. The study has highlighted the fact that climate change this century is characterized by increases in minimum temperatures of about 2 K, a more modest increase in maximum temperatures (in some instances a decrease of maxima in the latter part of the record), little trend in the precipitation data, and a general decrease of sunshine duration through to the mid 1980s. The interannual variability is generally large, and filtering of the data to remove high-frequency noise shows that the regional climate undergoes a series of fluctuations of between 8 and 20 years' duration. The temperature change over this century is of greater magnitude than the global temperature changes published in the literature, reflecting an amplification of the global signal in the Alpine region; warming has been most intense in the 1940s, followed by the 1980s; the cooling which intervened from the 1950s to the late 1970s was not sufficient to offset the warming in the middle of the century.Pressure statistics have been compiled as a means of providing a link between the regional-scale climatological variables and the synoptic, supra-regional scale. These statistics show that pressure also exhibits a number of decadal-scale fluctuations, with the appearance of a new and anomalous behavior in the 1980s; in this decade, pressure reaches annual average values far higher than at other times this century. The pressure field is well correlated with the North Atlantic Oscillation (NAO) Index for distinct periods of the record (1931–1950 and 1971–1990) and is almost decorrelated from the NAO Index for the other decades of the century; this is indicative of transition from one climatic régime to another, dominated by zonal flow when the correlation with the NAO Index is high. In the 1980s, when zonal flow over the North Atlantic is strong, episodes of persistent, anomalously high pressures (blocking highs) are seen to occur over Switzerland, particularly during the winter season. The difference between the zonal and non-zonal régimes is particularly marked between the decade of the 1950s and that of the 1980s.The impact of this change between the 1950s and the 1980s on a number of climatological variables has been investigated statistically in order to provide an illustration of the manner in which changes in synoptic régimes (i.e., climate change) impacts upon climate characteristics on a regional scale. The analysis shows that temperature, precipitation, snow depth, and sunshine duration are indeed sensitive to large-scale influences; not only can yearly mean changes be quantified, but also seasonal and monthly fluctuations.With 26 Figures     

Climate of scepticism: US newspaper coverage of the science of climate change

This two-part study integrates a quantitative review of one year of US newspaper coverage of climate science with a qualitative, comparative analysis of media-created themes and frames using a social constructivist approach. In addition to an examination of newspaper articles, this paper includes a reflexive comparison with attendant wire stories and scientific texts. Special attention is given to articles constructed with and framed by rhetoric emphasising uncertainty, controversy, and climate scepticism.     

Asking about climate change: Reflections on methodology in qualitative climate change research published in Global Environmental Change since 2000

There is increasing evidence that climate change will strongly affect people across the globe. Likely impacts of and adaptations to climate change are drawing the attention of researchers from many disciplines. In adaptation research focus is often on perceptions of climate change and on vulnerability and adaptation strategies in a particular region or community. But how do we research the ways in which people experience changing climatic conditions, the processes of decision-making, the actual adaptation strategies carried out and the consequences of these for actors living and dealing with climate change? On the basis of a literature review of all articles published in Global Environmental Change between 2000 and 2012 that deal with human dimensions of climate change using qualitative methods this paper provides some answers but also raises some concerns. The period and length of fieldwork and the number and types of interviews conducted are, for example, not always clear. Information on crucial aspects of qualitative research like researcher positionality, social positions of key informants, the use of field assistants, language issues and post-fieldwork treatment of data is also lacking in many articles. We argue that this lack of methodological information and reflections is particularly problematic in an interdisciplinary field such as climate change research and journals such as Global Environmental Change and that clearer communication is key to facilitate truly interdisciplinary dialogue.     

An overview of mainland China temperature change research

There has been significant effort devoted to investigating long-term trends in land surface air temperature over mainland China by Chinese scientists over the past 50 years, and much progress has been made in understanding dynamics of the changes. This review highlights research conducted by early Chinese climatologists, and particularly Professor Shaowu Wang from Peking University, with special focus on systematic work that has been conducted since the mid to late 1970s. We also discuss major issues that remain unresolved in past and current studies. The most recent analyses indicate that the country-average annual mean surface air temperature rose by 1.12°C over the past 115 years (1901–2015), with a rate of increase of about 0.10°C decade^–1. Temperatures have risen more rapidly since the 1950s, with the rate of increase of more than 0.25°C decade^-1. However, the recent increase in temperatures is in large part due to contamination by systematically biased data. These data are influenced by unprecedented urbanization in China, with a contribution of urbanization to the overall increase of annual mean temperatures in mainland China of about one third over the past half a century. If the bias is corrected, the rate of increase for the country-average annual mean surface air temperature is 0.17°C decade–1 over the last 50–60 years, which is approximately the same as global and Northern Hemispheric averages in recent decades. Future efforts should be focused towards the recovery and digitization of early-year observational records, the homogenization of observational data, the evaluation and adjustment of urbanization bias in temperature data series from urban stations, the analysis of extreme temperatures over longer periods including the first half of the 20th century, and the investigation of the observed surface air temperature change mechanisms in mainland China.     

On writing good histories of climate change and testing social science theories

David G. Victor is co-Leader, project on Implementation and Effectiveness of International Environmental Commitments (IEC), International Institute for Applied Systems Analysis, A-2361 Lazenburg, Austria. The views expressed here are his own.     

The discourses of climate change science: Scientific reporting,climate negotiations and the case of Papua New Guinea

This paper analyses climate science as a discourse to reveal how it enables and constrains climate change negotiations and action. Focusing on long-term outcomes projected in the Intergovernmental Panel on Climate Change’s Fifth Assessment Report and the World Bank’s “Turn Down the Heat” reports, this paper examines processes of discourse structuration and institutionalization to identify the dominant discourses which frame climate action. We trace the dominant discourses identified in the scientific reports – Survivalism, Ecological Modernisation and Economic Rationalism – through the Paris Agreement and selected Leader Statements and Intended Nationally Determined Contributions from COP21. From the 24 states included in this analysis, Papua New Guinea (PNG) is developed as a case study to investigate the hybridity and institutionalization of discourses. Even though PNG’s rhetoric and commitments at COP21 express Survivalism, the state’s policy frameworks rarely move beyond solutions found in Economic Rationalism and Ecological Modernisation. This suggests that states strategically adopt hybrid discourses drawn from climate science in line with their positionality, political economy and interests. Understanding how discourses drawn from climate science manifest in national policies has significant implications not only for how science is communicated at the international level but also for understanding different state positions in the global climate governance regime.     

Linking science more closely to policy-making: Global climate change and the national reorganization of science and technology policy

This paper examines the national trends behind recent efforts to link scientific research more closely to policy-making. It discusses the evolution of these efforts within the Clinton Administration in general and the U.S. Global Change Research Program (USGCRP) in particular. The paper describes the politics surrounding the establishment of the National Science and Technology Council (NSTC) and its Committee on Environment and Natural Resources, of which the USGCRP is a part, and concludes with an appraisal of the NSTC and of the “assessments” component of the USGCRP.     

An annotated bibliography on the greenhouse effect and climate change

The literature on climate change from an enhanced greenhouse effect is large and growing rapidly. The problems considered are increasingly inter-disciplinary. For these reasons many workers will find useful pointers to the literature in the fields interacting with, but outside of, their own. We present here an annotated bibliography on issues relating to changes in the concentrations of Earth's greenhouse gases. The areas covered include theory and numerical modelling of climate change; cycles involving carbon dioxide and other radiatively important trace gases; observations of climate change and the problems associated with those observations; paleoclimatology as it relates to previous changes in the greenhouse gases; the impacts on and interactions with managed and natural ecosystems from climate change; policy issues related to climate change and to the limitation of climate change; history of the study of the greenhouse effect; and some other causes of climate change. Selection of papers has been made to facilitate rapid introduction to most of the important issues and findings in an area. Over 600 articles, reports, and books are discussed.     

An example of fingerprint detection of greenhouse climate change

As an example of the technique of fingerprint detection of greenhouse climate change, a multivariate signal or fingerprint of the enhanced greenhouse effect is defined using the zonal mean atmospheric temperature change as a function of height and latitude between equilibrium climate model simulations with control and doubled CO₂ concentrations. This signal is compared with observed atmospheric temperature variations over the period 1963 to 1988 from radiosonde-based global analyses. There is a significant increase of this greenhouse signal in the observational data over this period.These results must be treated with caution. Upper air data are available for a short period only, possibly too short to be able to resolve any real greenhouse climate change. The greenhouse fingerprint used in this study may not be unique to the enhanced greenhouse effect and may be due to other forcing mechanisms. However, it is shown that the patterns of atmospheric temperature change associated with uniform global increases of sea surface temperature, with El NinoSouthern Oscillation events and with decreases of stratospheric ozone concentrations individually are different from the greenhouse fingerprint used here.     

Stories from the IPCC: An essay on climate science in fourteen questions

Women’s experiences as Intergovernmental Panel on Climate Change (IPCC) authors, have been explored showing how gender, race, nationality, etc. increase barriers to participate in the production of climate science even for the best scientists. Recently, the IPCC Gender Task Force, conducted another survey exploring barriers to participation in the IPCC that included men as well as women. The Gender Task Force released a report on gendered barriers mostly focusing on quantitative responses. This paper presents a qualitative analysis of the fourteen open-ended questions in the survey. In addition to qualitative analysis, storytelling and the concept of feminist objectivity are useful approaches to convey the complicated web of responses of over 500 scientists about their experiences participating in the IPCC and in climate science more broadly. Gender, race and nationality continue to be barriers. I stress the connection between exclusions of underrepresented scientists in the IPCC with the persistent western belief that science is an objective and impartial practice. The paper brings attention to exclusionary structures that prevent participation in the IPCC and in science more broadly, but also provides stories of how these are resisted. These stories go beyond recognizing people as disadvantaged toward addressing the intersecting structures that exclude people from participating in science. As climate science becomes more diverse, and evidence points toward the benefit of diversity for superior science, understanding barriers and opportunities for scientists participating in multidisciplinary and international reports such as the IPCC becomes increasingly important. The stories provide a theoretical and methodological catalyst for international science institutions who seek to increase the influence and presence of underrepresented groups in science and produce superior science.     

An economic analysis of potential impacts of climate change in Egypt

Projections of climate impacts on crop yields simulated for different General Circulation Model (GCM) scenarios are used, in a recursively dynamic general equilibrium framework, to account for potential economy-wide impacts of climate change in Egypt. Comparing these impact projections to those obtained under a reference, business-as-usual, scenario assuming some moderate changes in the political, economic or technological spheres, indicates that global warming has potentially negative effects. The analysis is based on a global assessment of potential climate change-induced variations in world commodity production and trade. The Egyptian agricultural sector, and the non-agricultural sector to a lesser extent, are projected to be increasingly less self-sufficient. Specific potential adverse impacts are identified. The simulation results show that high-cost adaptation measures involving major changes in the agricultural system and practices may mitigate these adverse impacts. Stimulating economic development of the rural areas and creating appropriate conditions for effective diffusion and development of technologies — particularly for the agricultural sector — would seem a desirable strategy. Perhaps, more importantly, the simulation results show that the assumption of exogenously determined technological progress may be inappropriate, in which case the potential adverse impacts of a future warming of the global climate are likely to be fewer than is indicated in this study — if prevailing constraints on productivity growth in the major food and feed grains are ‘released’ by endogenous advances in technology.