p—σ混合坐标原始方程模式对地气交换的敏感性试验

在五层及九层ｐ－σ混合坐标有限区域原始方程模式中,选择几种方案对影响地气系统之间动量、热量交换的拖曳系数进行了敏感性试验,并以一次寒潮为试验个例。试验结果表明：模式结果对拖曳系数的选取是敏感的;原模式对该系统在青藏高原地区的取值偏小,增大高牟地区的ＣＤ取值能取得更好的预报效果。     

大气季节内振荡的活动与El Nino

用广东省４７个测站１９５４－１９９０年各月的平均气温、降水、日照时数的标准化资料分别作按时间点分解的主分量分析,取其前６个主分量作为各测站的气候特征量,用相关系数－重心法作聚类分析,作出各月、全年综合要素的气候分区。结果表明：（１）将广东各月分为有较显著差异的５个区,则冬半年（１０－翌年４月）各月的分区形式较类似且规律性明显,夏半年（５－９月）各月的分区逐月变化明显,且分区形式差别较大。（２）若用６个自然季节的平均气温、降水、日照时数标准化资料分别作主分量分析,各取前３个主分量作为全年气候分区的特征量,则广东全年的气候区可分为东南沿海、西南沿海、西北内陆３个区。     

气候变暖对中国水稻生产可能影响的研究

利用随机天气模型,将大气环流模式预测的气候情景与水稻模式相链接,研究了气候变暖对中国水稻生产的可能影响。结果表明,大气中ＣＯ２浓度加倍,中国水稻主产区适宜水稻生长的日数将延长６～１１ｄ,积温增加２２０～３３０℃·ｄ。积温的相对增长率由南向北呈增长趋势。水稻产量形成期低温天气出现频率将减少,而高温天气出现的频率增加。若品种与播种、移栽期不变,水稻产量将下降;而若通过改变品种使作物生育期基本保持目前的状况,减产幅度将比品种不变时明显偏小,部分地区还有可能增产。     

IPCC AR6报告解读：气候系统对二氧化碳移除响应

IPCC AR6报告中控温1.5℃和2℃的低排放情景需要在21世纪中叶以后实现净负CO₂排放,这需要在很大程度上依赖CO₂移除措施。AR6对CO₂移除的主要评估结论如下：CO₂移除有潜力从大气中去除CO₂（高信度);如果CO₂移除量超过CO₂排放量,将实现净负CO₂排放,降低大气CO₂浓度,减缓海洋酸化（高信度);通过CO₂移除方法从大气中去除的CO₂会部分被海洋和陆地释放的CO₂抵消（非常高信度);如果净负CO₂排放可以实现并且持续,CO₂引起的全球升温趋势将会逐渐扭转,但是气候系统的其他变化（例如海平面升高）仍会在未来的几十年到千年尺度上持续（高信度);不同CO₂移除方法会对生物化学循环和气候产生广泛的影响,这些影响会加强或减弱CO₂移除的降温潜力,并且影响水资源、食物生产和生物多样性（高信度）。     

How stable are Australian farmers’ climate change risk perceptions? New evidence of the feedback loop between risk perceptions and behaviour

The exact relationship between people’s climate change attitudes and behaviour is a topic that engages policy-makers and researchers worldwide. Do climate change attitudes influence behaviour or is it possible that behaviour can change attitudes? This study uses a unique repeated survey dataset of 275 farmers (irrigators) in the southern Murray-Darling Basin from 2010–11 to 2015–16, to explore the dynamic relationship between climate change risk perceptions and farm adaptation behaviour. Farmers who had an increased risk exposure (expressed through higher debt, larger irrigated areas, greater share of permanent crops, and located in areas with higher temperatures and less rainfall) were more likely to agree climate change posed a risk. Whilst farmers became more accepting towards climate change over the time-period, a significant percentage of these attitudes were unstable. One reason suggested for this instability is the presence of a feedback loop between risk perceptions and behaviour. Namely, new evidence was found that farmers who agreed climate change was a risk in 2010–11, were more likely to undertake farm production decisions to reduce that risk (e.g. changing crop mix, reducing irrigated area and consequently selling water entitlements) – which had the impact of negatively feeding back and reducing their stated climate change risk perceptions in 2015–16. Conversely, farmers who were originally deniers were more likely to undertake somewhat riskier farm production decisions (e.g. increasing water utilisation rates and irrigation areas) – which consequently had the impact of positively increasing their climate change risk perceptions in 2015–16.     

Experience is not enough: A dynamic explanation of the limited adaptation to extreme weather events in public organizations

This study advances theory articulating the micro-level processes behind public organization adaptation to extreme weather. It tackles a persistent puzzle about the limited adaptation to extreme weather among public organizations: why does adaptation remain deficit after public organizations have experienced repeated extreme weather and some catastrophic consequences? We develop a computational agent-based model that integrates extant theory and data from semi-structured interviews of U.S. public transit agency managers, and use the model to investigate how micro-level cognition and behavior interact with environmental constraints to facilitate or impede the diffusion of adaptation. We articulate in greater detail how experience with influential extreme weather events matters to adaptation, highlighting that such experience is insufficient for adaptation to occur. A key insight is that the potential benefits from both increased risk perception and additional financial resources stemming from disaster- or non-disaster-induced opportunities can be underutilized, absent effective coupling between heightened risk perception and availability of resources that creates windows for adaptation. Using this insight, we further identify managerial and policy interventions with maximum leverage to promote adaptation to extreme weather in public organizations. The experiments show that slowing risk perception decay and synchronizing opportunities with extreme weather occurrences can stimulate adaptation.     

Climate change mitigation on tropical peatlands: A triple burden for smallholder farmers in Indonesia

The agricultural use and conversion of tropical peatlands is considered a major source of land-based greenhouse gas emissions. Thus, the protection and restoration of tropical peatlands has recently turned into an important strategy to mitigate global climate change. Little research exists that has investigated the impacts and dynamics that such climate mitigation efforts evoke in local communities living in and around peatlands. We present insights on this from Sumatra, Indonesia and use a climate justice lens to evaluate local outcomes. We show how an increasingly transnational network of state and non-state actors has become involved in developing new laws, policy programs and land-use agreements on Sumatra’s coastal peatlands, aiming at supposedly win–win low-carbon development pathways. We argue that such efforts are open to much of the same criticism that has been raised regarding previous policies and projects aimed at reducing GHGE from deforestation and forest degradation. These projects disregard local perspectives on development, fail to deliver the promised benefits and, through a reconfiguration of local land-use rights, reduce the capabilities of smallholder farmers to benefit from their land. In sum, our analysis suggests that recent policies and projects aimed at mitigating GHGE from tropical peatlands contribute to a redistribution of the global climate mitigation burden onto smallholder farmers in Indonesia. This occurs through their threefold assignment to protect forests, prevent fires and help restore degraded peatlands.     

春季欧亚-北太平洋上空大气质量迁移规律及其对中国同期气候异常的可能影响

利用1979～2013年NCEP/NCAR月平均再分析资料及NOAA研究中心的CMAP（CPC Merged Analysis of Precipitation）月平均降水资料,通过定义欧亚—北太平洋间大气质量迁移指数I_MAMEP,分析了春季欧亚—北太平洋上空大气质量迁移（MAMEP,Migration of Atmospheric Mass over Regions between Eurasia and North Pacific）的年际变化规律及其与同期中国气候异常的联系。结果表明:在北半球中高纬度存在一个纬向分布的欧亚—北太平洋遥相关型,且其可能对中国同期气候异常的形成具有重要影响。春季MAMEP指数具有显著的长期趋势,同时还具有2～4年及5～7年的振荡周期及明显的年代际变化特征。垂直环流和波动运动对欧亚—北太平洋间大气质量迁移具有重要作用。大气质量在欧亚西部低层异常辐合,高层异常辐散,在中、西太平洋地区低层异常辐散,高层异常辐合,在纬向上构成了顺时针的垂直环流圈,将西北太平洋地区的大气质量变动与欧亚大陆上空的变动联系了起来。另外,来自西欧大陆的波扰能量可传播至北太平洋,有利于这些区域上空位势高度异常扰动的维持。I_MAMEP与春季同期降水及地表气温异常关系密切。I_MAMEP为正时,东亚以北地区、鄂霍次克海西岸以及西欧沿岸降水显著减少,欧亚西部及我国华北地区降水显著增加。850 hPa上西伯利亚受反气旋式环流控制,太平洋上空受气旋式环流控制,引起欧亚大陆北部地表显著增温,西伯利亚以东、我国东北、华北—江淮地区及韩国、日本南部地表显著降温。西欧—我国西北部分地区大面积显著降温现象与这两个地区受异常反气旋东侧的偏北气流影响有关。这些结果有利于人们更深刻认识区域春季气候异常形成机理。     

Effectiveness of flood damage mitigation measures: Empirical evidence from French flood disasters

Recent destructive flood events and projected increases in flood risks as a result of climate change in many regions around the world demonstrate the importance of improving flood risk management. Flood-proofing of buildings is often advocated as an effective strategy for limiting damage caused by floods. However, few empirical studies have estimated the damage that can be avoided by implementing such flood damage mitigation measures. This study estimates potential damage savings and the cost-effectiveness of specific flood damage mitigation measures that were implemented by households during major flood events in France. For this purpose, data about flood damage experienced and household flood preparedness were collected using a survey of 885 French households in three flood-prone regions that face different flood hazards. Four main conclusions can be drawn from this study. First, using regression analysis results in improved estimates of the effectiveness of mitigation measures than methods used by earlier studies that compare mean damage suffered between households who have, and who have not, taken these measures. Second, this study has provided empirical insights showing that some mitigation measures can substantially reduce damage during floods. Third, the effectiveness of the mitigation measures is very regional dependent, which can be explained by the different characteristics of the flood hazard in our sample areas that experience either slow onset river flooding or more rapid flash and coastal flooding. Fourth, the cost-efficiency of the flood damage mitigation measures depends strongly on the flood probability faced by households.     

Geographical imbalances and divides in the scientific production of climate change knowledge

Studies on scientific production of climate change knowledge show a geographical bias against the developing and more vulnerable regions of the world. If there is limited knowledge exchange between regions, this may deepen global knowledge divides and, thus, potentially hamper adaptive capacities. Consequently, there is a need to further understand this bias, and, particularly, link it with the exchange of knowledge across borders. We use a world-wide geographical distribution of author affiliations in >15,000 scientific climate change publications to show that (1) research production mainly takes place in richer, institutionally well-developed countries with cooler climates and high climate footprints, and (2) the network of author affiliations is structured into distinct modules of countries with strong common research interests, but with little knowledge exchange between modules. These modules are determined mainly by geographical proximity, common climates, and similar political and economic characteristics. This indicates that political-economic, social and educational-scientific initiatives targeted to enhance local research production and collaborations across geographical-climate module borders may help diminish global knowledge divides. We argue that this could strengthen adaptive capacity in the most vulnerable regions of the world.