A new framework for isolating individual feedback processes in coupled general circulation climate models. Part I: formulation

This paper proposes a coupled atmosphere–surface climate feedback–response analysis method (CFRAM) as a new framework for estimating climate feedbacks in coupled general circulation models with a full set of physical parameterization packages. The formulation of the CFRAM is based on the energy balance in an atmosphere–surface column. In the CFRAM, the isolation of partial temperature changes due to an external forcing or an individual feedback is achieved by solving the linearized infrared radiation transfer model subject to individual energy flux perturbations (external or due to feedbacks). The partial temperature changes are addable and their sum is equal to the (total) temperature change (in the linear sense). The decomposition of feedbacks is based on the thermodynamic and dynamical processes that directly affect individual energy flux terms. Therefore, not only those feedbacks that directly affect the TOA radiative fluxes, such as water vapor, clouds, and ice-albedo feedbacks, but also those feedbacks that do not directly affect the TOA radiation, such as evaporation, convections, and convergence of horizontal sensible and latent heat fluxes, are explicitly included in the CFRAM. In the CFRAM, the feedback gain matrices measure the strength of individual feedbacks. The feedback gain matrices can be estimated from the energy flux perturbations inferred from individual parameterization packages and dynamical modules. The inter-model spread of a feedback gain matrix would help us to detect the origins of the uncertainty of future climate projections in climate model simulations.     

Global Oceanic Climate Anomalies in 1980''''s

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Global Oceanic Climate Anomalies in 1980’s

The climate in the 1980’s is characterized by the appearance of two strong ENSO events and by the warmest dec-ade in global mean temperature. Whether there is a linkage between ENSO and global warming? This paper shows the climate anomaly patterns over the global ocean in the 1980’s and their comparison with that of ENSO composite mode and that simulated by 2 × CO2, indicating the role of super ENSO in the establishment of new climate regime in the 1980’s     

Will the tropical land biosphere dominate the climate–carbon cycle feedback during the twenty-first century?

Global warming caused by anthropogenic CO₂ emissions is expected to reduce the capability of the ocean and the land biosphere to take up carbon. This will enlarge the fraction of the CO₂ emissions remaining in the atmosphere, which in turn will reinforce future climate change. Recent model studies agree in the existence of such a positive climate–carbon cycle feedback, but the estimates of its amplitude differ by an order of magnitude, which considerably increases the uncertainty in future climate projections. Therefore we discuss, in how far a particular process or component of the carbon cycle can be identified, that potentially contributes most to the positive feedback. The discussion is based on simulations with a carbon cycle model, which is embedded in the atmosphere/ocean general circulation model ECHAM5/MPI-OM. Two simulations covering the period 1860–2100 are conducted to determine the impact of global warming on the carbon cycle. Forced by historical and future carbon dioxide emissions (following the scenario A2 of the Intergovernmental Panel on Climate Change), they reveal a noticeable positive climate–carbon cycle feedback, which is mainly driven by the tropical land biosphere. The oceans contribute much less to the positive feedback and the temperate/boreal terrestrial biosphere induces a minor negative feedback. The contrasting behavior of the tropical and temperate/boreal land biosphere is mostly attributed to opposite trends in their net primary productivity (NPP) under global warming conditions. As these findings depend on the model employed they are compared with results derived from other climate–carbon cycle models, which participated in the Coupled Climate–Carbon Cycle Model Intercomparison Project (C4MIP).

CO2 threshold for millennial-scale oscillations in the climate system: implications for global warming scenarios

We present several equilibrium runs under varying atmospheric CO₂ concentrations using the University of Victoria Earth System Climate Model (UVic ESCM). The model shows two very different responses: for CO₂ concentrations of 400 ppm or lower, the system evolves into an equilibrium state. For CO₂ concentrations of 440 ppm or higher, the system starts oscillating between a state with vigorous deep water formation in the Southern Ocean and a state with no deep water formation in the Southern Ocean. The flushing events result in a rapid increase in atmospheric temperatures, degassing of CO₂ and therefore an increase in atmospheric CO₂ concentrations, and a reduction of sea ice cover in the Southern Ocean. They also cool the deep ocean worldwide. After the flush, the deep ocean warms slowly again and CO₂ is taken up by the ocean until the stratification becomes unstable again at high latitudes thousands of years later. The existence of a threshold in CO₂ concentration which places the UVic ESCM in either an oscillating or non-oscillating state makes our results intriguing. If the UVic ESCM captures a mechanism that is present and important in the real climate system, the consequences would comprise a rapid increase in atmospheric carbon dioxide concentrations of several tens of ppm, an increase in global surface temperature of the order of 1–2°C, local temperature changes of the order of 6°C and a profound change in ocean stratification, deep water temperature and sea ice cover.     

西北太平洋热带气旋气候变化的若干研究进展

热带气旋气候变化研究不仅是当前国际热带气旋气候界的热点科学问题,而且也是具有现实意义的社会问题,各国气象学者和科学家们对此进行了广泛的研究。虽然热带气旋活动与气候变化之间的关系及其相应的内在物理机制至今还处在探究之中,但是近20多年来热带气旋气候学的研究还是取得了显著的进展。本文主要针对濒临中国的西北太平洋海域,回顾了热带气旋活动季节内、年际、年代际变化及其全球变暖背景下的变化趋势的气候学研究。此外,文中也对西北太平洋热带气旋气候学的研究进行了展望,并提出了该领域中一些亟待解决的科学问题。     

西藏冰湖溃决灾害事件极端气候特征

以1960年以来西藏境内已有记载的27次冰湖溃决灾害事件作为研究对象,基于西藏国家气象站点长时间序列（有效记录至今）日气温和日降雨数据,计算得到16个极端气温指数和6个极端降雨指数。通过主成分变换,提取综合极端气温指数和综合极端降雨指数,并进行历史（10年内对比）极端气候特征对比,获得冰湖溃决灾害发生当年及当月极端气候状态,结果表明西藏冰湖溃决灾害发生期（当年及当月）极端气候特征显著,反映极端气候状态对于激发西藏冰湖溃决灾害发生的重要贡献,具体表现为：(1) 67%（18次）的冰湖溃决事件发生当年综合极端气温指数和综合极端降雨指数均大于前期50%年份的综合极端气候指数,其中,13次灾害发生当年极端气候异常水平超过前期70%年份;(2)已有灾害暴发月份记载的25次冰湖溃决事件中,19次冰湖溃决事件发生当月极端气候指数异常偏高,11次冰湖溃决事件发生当月极端气温和极端降水均大于75%往年同期综合极端气候指数;(3)部分灾害事件如扎日错（1981年6月)、龙纠错溃决（2000年8月）等,灾害发生当年极端气温状态低于往年,而暴发当月综合极端气温指数和综合极端降雨指数均大于历史同期水平,表现为加剧状态;(4)所有冰湖溃决灾害发生当月的综合极端气温指数均高于往年同期指数,表明短历时极端气温事件对高原冰湖溃决灾害形成具有重要影响。     

全球气候变暖的检测及成因分析

文章对近年来有关全球气候变暖中一些问题的研究进展作了总结,主要结论如下：全球平均地面气温在过去一百年来上升0.5℃。80年代是近百年来最暖的10年。90年代初继续变暖。1990年是近百年来最暖的一年。1991年仅次於1990年。但是近百年气候变暖的幅度仍未超过自然变率。近千年中,中世纪暖期（900—1300年）的温暖程度就可能与20世纪相当,而小冰期（1550—1850年）气温则可能比20世纪低1.0—1.5℃。已经证实,对几十年到几百年尺度,太阳活动强时太阳总辐射也强,但变化幅度尚待进一步确定。强火山爆     

CMIP5多模式对阿留申低压气候特征的模拟检验与预估

利用观测的海温资料和海平面气压资料,检验了CMIP5(Coupled Model Intercomparison Project 5,CMIP5)多模式对阿留申低压(Aleutian Low,AL)特征指数的时空分布和变化的模拟能力;从AL周期及变化趋势等方面,分析了CMIP5模式预估的未来AL的变化特征。结果表明,CMIP5模式及其集合平均能够很好地模拟AL的环流结构,对AL的气候态有着较强的模拟能力,尤其是模式对于东太平洋海表温度的模拟能力直接影响其对于AL的模拟效果。模式的集合平均对变率强度的模拟偏强,且对于变率的模拟效果逊于对气候态的模拟。22个模式中的16个模式能模拟出AL强度指数的年代际变化周期,对年代际周期有着较好的刻画能力。Historical试验下对于AL的变化趋势存在着较大的不确定性,而相对于两种不同排放情景,随着排放的增加,AL更加偏北,强度增强,年际、年代际周期变得更加显著。在两种排放情景下模式的集合平均以及多数模式模拟出AL有着向北和增强的趋势。     

American evangelicals and global warming

American evangelicals have long played a significant role in American culture and politics. Drawing from a nationally representative survey, this article describes American evangelicals’ global warming risk assessments and policy preferences and tests several theory-based factors hypothesized to influence their views. American evangelicals are less likely than non-evangelicals to believe that global warming is happening, caused mostly by human activities, and causing serious harm, yet a majority of evangelicals are concerned about climate change and support a range of climate change and energy related policies. Multiple regression analyses found that the combination of biospheric, altruistic, and egoistic value orientations is a more significant predictor of evangelicals’ risk assessments and policy support than negative affect, egalitarian or individualistic worldviews, or socio-demographic variables.     

Projection of the East Asian westerly jet under six global warming targets

东亚高空急流(简称急流)对夏季东亚地区的天气和气候有着重要影响。本文利用CMIP5的历史气候模拟试验和RCP8.5路径下的未来气候变化预估试验数据,预估了急流在6个全球变暖阈值(1.5℃,2.0℃,2.5℃,3.0℃,3.5℃和4.0℃)下相对于当代气候的变化情况。结果表明东亚高空西风在1.5℃阈值下略微减弱。在2.0℃阈值下,西风在急流轴(约40°N)南侧增强,北侧减弱。这种变化趋势在2.5℃和更高的变暖阈值下愈加明显,使急流轴逐渐向南移动,但急流强度变化不大。研究表明,在急流的入口和出口区,对流层中上层大气升温速度相对较慢,导致在急流轴南(北)侧出现向南(北)的负(正)经向温度梯度,使西风在南(北)侧增强(减弱).     

全球变暖中的科学问题

2013年各国政府间气候变化专门委员会（IPCC）第一工作组发布了第五次气候变化科学评估报告,以大量的观测分析和气候模式模拟证据,继续强调由于人类排放增加,全球正在变暖,未来将继续变暖的观点。本文综述研究全球变暖的几个深层次的科学问题,即多套全球气温观测资料的差异、不同标准气候态时段的作用、20世纪全球变暖的检测和归因及未来全球气温变化的走向,以此提出需进一步研究的科学问题。结果表明;需要进一步提高观测资料的质量;注意不同标准气候态时段对应的数值的不同;应进一步改善气候模式模拟年代际变率的能力及研究近15 a全球变暖减缓和停滞的原因,从而改善气候模式的模拟效果;造成预估未来全球气候变化的不确定性主要来自气候模式的差异、未来排放情景的差异及气候系统内部变率影响和自然外强迫的作用。     

Personal experience with climate change predicts intentions to act

The public's willingness to engage in mitigation actions has not received as much attention as the level of belief in Global Warming (GW), especially on the international stage. Research in Western nations indicates that people systematically misunderstand GW and the actions required for mitigation. Important factors that influence judgments about mitigation actions include personal experiences, beliefs, knowledge, values, and worldviews. We present results of an international survey (25 samples from 24 countries) measuring general intentions to act and willingness to engage in specific actions. Our analysis reveals that endorsement of specific actions is (a) lower than general endorsement of mitigation, (b) accompanied by higher intra-individual variance, and (c) more strongly related to personal experiences with GW. This pattern can be attributed to the compatibility between the proximal construal of specific actions and the nature of the personal experience. Lastly we provide recommendations on how these findings can be used to encourage mitigation action.     

Early warnings and emerging accountability: Total’s responses to global warming, 1971–2021

Building upon recent work on other major fossil fuel companies, we report new archival research and primary source interviews describing how Total responded to evolving climate science and policy in the last 50 years. We show that Total personnel received warnings of the potential for catastrophic global warming from its products by 1971, became more fully informed of the issue in the 1980s, began promoting doubt regarding the scientific basis for global warming by the late 1980s, and ultimately settled on a position in the late 1990s of publicly accepting climate science while promoting policy delay or policies peripheral to fossil fuel control. Additionally, we find that Exxon, through the International Petroleum Industry Environmental Conservation Association (IPIECA), coordinated an international campaign to dispute climate science and weaken international climate policy, beginning in the 1980s. This represents one of the first longitudinal studies of a major fossil fuel company’s responses to global warming to the present, describing historical stages of awareness, preparation, denial, and delay.     

Who remembers a hot summer or a cold winter? The asymmetric effect of beliefs about global warming on perceptions of local climate conditions in the U.S.

This paper explores the phenomenon of local climate perception and the extent to which public perceptions match climate conditions as recorded in instrumental climate data. We further examine whether perceptions of changes in local climates are influenced by prior beliefs about global warming, through the process of motivated reasoning. Using national survey data collected in the United States in 2011, we find that subjective experiences of seasonal average temperature and precipitation during the previous winter and summer were related to recorded conditions during each season. Beliefs about global warming also had significant effects on subjective experiences with above-normal temperatures, particularly among those who believed that global warming is not happening. When asked about the summer of 2010, those who believed that global warming is not happening were significantly less likely to report that they had experienced a warmer-than-normal summer, even when controlling for demographics and local climate conditions. These results suggest that the subjective experience of local climate change is dependent not only on external climate conditions, but also on individual beliefs, with perceptions apparently biased by prior beliefs about global warming.     

太原气候变暖特征及主要极端天气气候事件变化研究

近45a来，太原平川和山区年平均气温为明显上升趋势，夜间增温是太原气候变暖的一个重要特征。1986年、1993年分别为山区和平川年平均气温转折年份，山区从1985年开始冬季平均气温发生突变。近45a来，太原年降水量呈减少趋势，主要是夏、秋季降水减少造成。在气候变暖的背景下，太原平川和山区年暴雨日数变化平稳，高温和春旱发生频次在增加，山区夏旱也呈缓慢增加趋势；太原山区霜期明显缩短，初霜在推迟，终霜在提前。     

A Modeling Study of Climate Change and Its Implication for Agriculture in China Part II: The Implication of Climate Change for Agriculture in China

The potential CO2-induced impacts on the geographical shifts of wheat growth zones in China were studied from seven GCMs outputs. The wheat growth regions may move northward and westward under the condition of a doubling CO2 climate. The wheat cultivation features and variety types may also assume significant changes. Climatic warming would have a positive influence in Northeast China, but high temperature stress may be produced in some regions of central and southern China. Higher mean air temperatures during wheat growth, particularly during the reproductive stages, may increase the need for earlier-maturing and more heat-tolerant cultivars.     

云南冰雹的变化特征

利用1961-2008年云南120个测站逐月冰雹资料,分析了近50年云南冰雹的时空变化特征及其对气候变暖的响应。结果表明：（1）云南冰雹具有明显的区域分布。全年冰雹日数从云南西北到东南大致呈多—少—多—少相间隔的区域分布特征;夏季与秋季分布相似,滇西北偏多,滇西南偏少;春季与冬季分布相似,滇西北及滇东北偏少,从西北到东...     

Considering the options: climate targets for all countries

Abstract

This paper assesses five options for targets that could be taken by all countries to meet the ultimate objective of the climate change convention: fixed, binding targets; dynamic targets; non-binding targets; sectoral targets; policies and measures. Each is evaluated according to criteria of environmental effectiveness, cost-effectiveness, contribution to economic growth and sustainable development, and equity. While fixed, binding targets continue to be viable for industrialised countries, they do not seem suitable for many developing countries in the near future. Dynamic targets could alleviate developing countries' concerns about constraining their development as well as broader concerns about possible introduction of “hot air” in a world trading regime; they could also be considered for some or all industrialised countries. Non-binding targets could be politically appealing to developing countries, alleviate fears about development and/or hot air, but might only allow conditional participation in emissions trading by developing countries. Sectoral targets could offer a pragmatic first step—although their cost-effectiveness might be questioned. Finally, targets based on commitments to implement specific policies and measures might drive mitigation action and be part of negotiated packages including financial and technological co-operation. All these options may coexist in the future.     

Policy innovation in a changing climate: Sources,patterns and effects

States have been widely criticized for failing to advance the international climate regime. Many observers now believe that a “new” climate governance is emerging through transnational and/or local forms of action that will eventually plug the resulting governance gaps. Yet states, which remain oddly absent from most discussions of the “new” governance, will remain key players as governance becomes more polycentric. This paper introduces a special issue that explores the ability of states to rise to these interconnected challenges through the analytical prism of policy innovation. It reveals that policy innovation is much more multi-dimensional than is often thought; it encompasses three vital activities: invention (centering on the ‘source’ of new policy elements), diffusion (that produces different ‘patterns’ of policy adoption), and the evaluation of the ‘effects’ that such innovations create in reality. The papers, which range from qualitative case studies to large ‘n’ quantitative studies, offer new insights into the varied roles that states play in relation to all three.They show, for instance that: the policy activity of states has risen dramatically in the past decade; that state innovation is affected to similar degrees by internal and external factors; and that policies that offer flexibility to target groups on how to meet policy goals are most effective but that voluntary reporting requirements are ineffective. This paper draws upon these and many other insights to offer a much more nuanced reflection on the future of climate governance; one that deservedly puts states at the front and center of analysis.