南昌市区与城郊盛夏温度对比观测与分析

通过对南昌市区和城郊1个月的对比观测与分析,发现了造成南昌市盛夏城区最高气温比城郊高的一些原因,并对南昌市盛夏高温预报服务提出了参考建议。     

Global fossil energy markets and climate change mitigation – an analysis with REMIND

We analyze the dynamics of global fossil resource markets under different assumptions for the supply of fossil fuel resources, development pathways for energy demand, and climate policy settings. Resource markets, in particular the oil market, are characterized by a large discrepancy between costs of resource extraction and commodity prices on international markets. We explain this observation in terms of (a) the intertemporal scarcity rent, (b) regional price differentials arising from trade and transport costs, (c) heterogeneity and inertia in the extraction sector. These effects are captured by the REMIND model. We use the model to explore economic effects of changes in coal, oil and gas markets induced by climate-change mitigation policies. A large share of fossil fuel reserves and resources will be used in the absence of climate policy leading to atmospheric GHG concentrations well beyond a level of 550 ppm CO₂-eq. This result holds independently of different assumptions about energy demand and fossil fuel availability. Achieving ambitious climate targets will drastically reduce fossil fuel consumption, in particular the consumption of coal. Conventional oil and gas as well as non-conventional oil reserves are still exhausted. We find the net present value of fossil fuel rent until 2100 at 30tril.US$ with a large share of oil and a small share of coal. This is reduced by 9 and 12tril.US$ to achieve climate stabilization at 550 and 450 ppm CO₂-eq, respectively. This loss is, however, overcompensated by revenues from carbon pricing that are 21 and 32tril.US$, respectively. The overcompensation also holds under variations of energy demand and fossil fuel supply.     

Variability of meteorological elements shaping biometeorological conditions in Szczecin, Poland

In this study, the time and spatial variability of perceptible conditions, determined on the basis of effective temperature in the area of the Szczecin agglomeration are presented. The study was based on air temperature, relative humidity and wind speed data acquired during 2005?C2007 from three emissions stations located in the centre and on the outskirts of the city of Szczecin, Poland. The differences in the values of the measured meteorological components between the studied city locations, in terms of their magnitude and daily structure, were analysed by month and calendar season. The results demonstrate that the temperatures in the city centre were considerably higher throughout the daily cycle, which was most evident during the summer in contrast to winter when the differences were the lowest. Mainly June and July, at 17?C24 UTC (Coordinated Universal Time), were characterized by the average highest intensity of the urban heat island. Reduced relative humidity in the centre of Szczecin, as compared to the suburban areas, was observed particularly during summer. Throughout the daily cycle, this trend was also observed during spring, primarily during the night. Wind speed within the congested housing in the centre of Szczecin was over two-fold lower as compared to the unbuilt-up areas of the outskirts, irrespective of the time of the day and season of the year. Modification of the air humidity, thermal and anemometric conditions was reflected in a considerable variation in heat perception. In summer and spring, between 1300 and 2100 UTC, the most burdening biometeorological conditions, sensed as ??hot?? and ??very hot?? weather, prevailed in the city centre. During winter, on the other hand, the unbuilt-up areas on the city outskirts were the most unfavourable in terms of biothermal conditions, with the predominant categories of perceptible weather conditions throughout the daily cycle being ??cold?? and ??very cold??.     

Water resources for agriculture in a changing climate: international case studies

This integrated study examines the implications of changes in crop water demand and water availability for the reliability of irrigation, taking into account changes in competing municipal and industrial demands, and explores the effectiveness of adaptation options in maintaining reliability. It reports on methods of linking climate change scenarios with hydrologic, agricultural, and planning models to study water availability for agriculture under changing climate conditions, to estimate changes in ecosystem services, and to evaluate adaptation strategies for the water resources and agriculture sectors. The models are applied to major agricultural regions in Argentina, Brazil, China, Hungary, Romania, and the US, using projections of climate change, agricultural production, population, technology, and GDP growth.For most of the relatively water-rich areas studied, there appears to be sufficient water for agriculture given the climate change scenarios tested. Northeastern China suffers from the greatest lack of water availability for agriculture and ecosystem services both in the present and in the climate change projections. Projected runoff in the Danube Basin does not change substantially, although climate change causes shifts in environmental stresses within the region. Northern Argentina's occasional problems in water supply for agriculture under the current climate may be exacerbated and may require investments to relieve future tributary stress. In Southeastern Brazil, future water supply for agriculture appears to be plentiful. Water supply in most of the US Cornbelt is projected to increase in most climate change scenarios, but there is concern for tractability in the spring and water-logging in the summer.Adaptation tests imply that only the Brazil case study area can readily accommodate an expansion of irrigated land under climate change, while the other three areas would suffer decreases in system reliability if irrigation areas were to be expanded. Cultivars are available for agricultural adaptation to the projected changes, but their demand for water may be higher than currently adapted varieties. Thus, even in these relatively water-rich areas, changes in water demand due to climate change effects on agriculture and increased demand from urban growth will require timely improvements in crop cultivars, irrigation and drainage technology, and water management.     

Testing supply-side climate policies for the global steam coal market—can they curb coal consumption?

The achieved international consensus on the 1.5–2 °C target entails that most of current fossil fuel reserves must remain unburned. A major contribution has to come from coal as both the most abundant and the most emission-intensive fuel. Currently, a majority of climate policies aiming at reducing coal consumption are directed towards the demand side. In the absence of a global carbon-pricing regime, these policies are prone to carbon leakage and other adverse effects. Supply-side climate policies present an alternative and increasingly discussed approach to reduce the consumption of fossil fuels. In this article, I employ a numerical model of the international steam coal market to examine two supply-side policies that are currently discussed in academic literature and by policy-makers, alike: (1) a production subsidy reform introduced in major coal-producing countries and (2) a globally implemented moratorium on new coal mines. The model simulates global patterns of coal supply, demand, and international trade, with endogenous investment in coal production and transportation capacities. I find that mere production subsidy removal, while associated with a small positive total welfare effect, leads to a minor reduction of global emissions. By contrast, a mine moratorium induces a much more pronounced reduction in global coal consumption by effectively limiting coal availability and strongly increasing prices. Depending on the specification of reserves, the moratorium can induce a coal consumption path consistent with the 1.5–2 °C target.     

Effects of summer precipitation on urban transportation

Potential shifts in summer precipitation due to an enhanced greenhouse effect indicate the possibility of more rain days and heavier rains in the Midwest, and this study assessed the effects of such changes on transportation in Chicago using a 3-year period of data. Traffic accidents in the metropolitan area doubled on rainy days, with 30% more accidents in more densely populated urban areas than in suburban-rural areas. During rain events accident severity (number of injuries) was 55% higher in suburban and rural areas where less dense but higher speed traffic flows exist than in the city, however. Rain days during dry months produced more accidents and injuries than during normal or wet months. Three times as many accidents occurred during heavy rain periods (> 12.8 mm) as during nonrain conditions. Rain had a negligible influence on weekday traffic volume on busy highways but there was a 9% decrease in traffic volume on rainy weekends. A 3–5% decrease in ridership of public transportation occurred on rainy days, with most decreases during midday. Nationally, 27% of all fatality-producing aircraft accidents occurred during rainy weather conditions, as did 57% of the 30-min flight delays at Chicago's O'Hare Airport. Results suggest that given continued transportation use patterns extend into the future, a future climate with more summer rain days, somewhat higher rain rates, and more storms would mean more total vehicular accidents, more total injuries in vehicular accidents, decreased ridership on public transportation systems, and more aircraft accidents and delays. A drier climate would likely experience fewer moderate to heavy rain events but results show that rain events during drier conditions produced a greater frequency of accidents and injuries per event than during wetter conditions.     

Evolution of the Parisian urban climate under a global changing climate

The evolution of the Parisian urban climate under a changing climate is analyzed from long-term offline numerical integrations including a specific urban parameterization. This system is forced by meteorological conditions based on present-climate reanalyses (1970–2007), and climate projections (2071–2099) provided by global climate model simulations following two emission scenarios (A1B and A2). This study aims at quantifying the impact of climate change on air temperature within the city and in the surroundings. A systematic increase of 2-meter air temperature is found. In average according to the two scenarios, it reaches +?2.0/2.4°C in winter and +?3.5/5.0°C in summer for the minimum and maximum daily temperatures, respectively. During summer, the warming trend is more pronounced in the surrounding countryside than in Paris and suburbs due to the soil dryness. As a result, a substantial decrease of the strong urban heat islands is noted at nighttime, and numerous events with negative urban heat islands appear at daytime. Finally, a 30% decrease of the heating degree days is quantified in winter between present and future climates. Inversely, the summertime cooling degree days significantly increase in future climate whereas they are negligible in present climate. However, in terms of accumulated degree days, the increase of the demand in cooling remains smaller than the decrease of the demand in heating.     

北京及周边地区城市尺度热岛特征及其演变

采用北京及市郊地区共16个标准国家气候站的1961～2000年40年温度资料对北京及周边地区的城市尺度热岛特征及其演变进行了研究.研究表明北京城区与郊区温度是同位相升降,且郊区温度一直低于城区.其温差维持并同位向振荡,温度逐年升高,城区与郊区温差逐年增大,表明北京热岛效应一直稳定存在,而且北京的热岛效应在随时间加剧.以海淀为代表的北京城区大部热岛效应显著,门头沟、石景山、丰台、房山和通县等地是局地升温的显著区域.因此,北京具有城市、卫星城市"热岛"多中心的复杂特征.分析热岛效应增强的趋势表明世纪末的10年与80年代的10年相比,北京城区与郊区的热岛效应增强趋势显著.特别是以海淀为代表的北京城区大部,热岛效应进一步明显增强;北京的东南部的局地升温效应加剧,通县也是一个明显的升温区域,并有一个从河北省伸向北京东南部的"暖脊". 尺度滤波分析表明,北京城市热岛效应10年变化的增强区域与城市位置十分吻合.北京城市热岛效应还具有中尺度特征.以海淀为代表的北京城区大部是热岛的主要中心,主中心内还有几个更小的高中心嵌套其中,分别位于三环路以内的西部和北部.北京城郊热岛效应发展趋势仍是严峻的,须进一步努力进行北京及周边地区环境的改善.     

Assessment of balanced burden-sharing in the 2050 EU climate/energy roadmap: a metamodeling approach

In this paper we propose a non-cooperative meta-game approach to designing and assessing climate agreements among 28 European countries that will be compatible with the EU 2050 climate target. Our proposed game model is identified through statistical emulation of a large set of numerical simulations performed with the computable general equilibrium model GEMINI-E3. In this game, the players are the 28 European countries, the payoffs are related to welfare losses due to abatements and the strategies correspond to the supply of emission rights on the European carbon market. We show it is possible to design a fair burden-sharing rule that equalizes welfare losses between countries to approximately 1.2 % of their discounted household consumption. The associated European CO₂ price in 2050 reaches $1100, a figure in line with previous studies. Lastly, the paper discusses various implementation issues of these types of negotiations and evaluates the cost of non-cooperation among EU countries.     

西安市气候变暖与城市热岛效应问题研究

选取1961—2003年西安站和周围4站月平均气温资料, 利用西安站与周围4站气温距平滑动平均变化趋势的差异, 发现该站平均气温有两个明显的上升期, 热岛效应使西安站平均升温1.07 ℃, 并建立了西安市城市热岛效应模型。在此基础上分离了气候变暖过程中由于城市热岛效应引起的增温作用。     

城市气候承载力定量化评价方法初探

本文从气候天然容量、城市气候压力和城市协调发展能力3个方面选取24个指标构建较完整的城市气候承载力评价指标体系。气候天然容量指数采用内梅罗指数法计算,城市气候压力指数和城市协调发展能力指数采用基于熵权的综合评价方法计算,进而构建城市气候承载力综合评价函数以量化评价结果。以上海市为例,对其气候承载力进行定量化评价。研究表明,本文建立的气候承载力评价指标体系是可行的,它可以描述某一城市时域上的变化,也可以对区域气候承载力开发利用过程中存在的问题进行甄别,并可作为气候预警响应的依据,为我国建立区域气候安全管理机制提供技术参考。分析上海市2004-2013年这10年间气候承载力的变化趋势,结果表明研究期内上海市气候承载力整体劣于基准年值,且因深受气候天然容量的影响而处于较大波动状态。     

低纬高原城市昆明的气候特征

以低纬高原城市昆明为研究对象，利用城市内的实测资料与城郊昆明气象站的资料进行了比较研究，分析了城市内外的气候特征、变化规律及其差异，得到了一些有益的结果，可为探讨低纬高原城市气候特征和形成机制、城市环境污染防治及城市建筑的规划、设计提供依据。     

2000—2017年山地城市百色气候承载力定量评价

利用2000—2017年百色市气象资料和城市社会经济发展数据,构建以气候天然容量、极端气候事件压力、城市气候压力和城市协调发展能力四个评价指数组成的城市气候承载力综合函数,客观定量评价广西西部山地城市百色2000—2017年的气候承载力变化。结果表明：21世纪以来,百色市的气候承载力整体呈现一种波动上升的状态,反映百色的城市建设与气候之间的协调力增强,城市建设发展仍有较大的气候承载空间。百色城市气候承载力对极端天气气候事件,特别是干旱事件较为敏感;人为影响因子对气候承载力具有重要影响。提升气候承载力和应对气候变化能力应从提高防御自然灾害能力和城市协调发展能力、降低城市气候压力着手,建立可持续发展的城市气候生态系统。     

Impacts of Climate Change on the Global Forest Sector

The path and magnitude of future anthropogenic emissions of carbon dioxide will likely influence changes in climate that may impact the global forest sector. These responses in the global forest sector may have implications for international efforts to stabilize the atmospheric concentration of carbon dioxide. This study takes a step toward including the role of global forest sector in integrated assessments of the global carbon cycle by linking global models of climate dynamics, ecosystem processes and forest economics to assess the potential responses of the global forest sector to different levels of greenhouse gas emissions. We utilize three climate scenarios and two economic scenarios to represent a range of greenhouse gas emissions and economic behavior. At the end of the analysis period (2040), the potential responses in regional forest growing stock simulated by the global ecosystem model range from decreases and increases for the low emissions climate scenario to increases in all regions for the high emissions climate scenario. The changes in vegetation are used to adjust timber supply in the softwood and hardwood sectors of the economic model. In general, the global changes in welfare are positive, but small across all scenarios. At the regional level, the changes in welfare can be large and either negative or positive. Markets and trade in forest products play important roles in whether a region realizes any gains associated with climate change. In general, regions with the lowest wood fiber production cost are able to expand harvests. Trade in forest products leads to lower prices elsewhere. The low-cost regions expand market shares and force higher-cost regions to decrease their harvests. Trade produces different economic gains and losses across the globe even though, globally, economic welfare increases. The results of this study indicate that assumptions within alternative climate scenarios and about trade in forest products are important factors that strongly influence the effects of climate change on the global forest sector.     

Effects of Climatic Change on a Water Dependent Regional Economy: A Study of the Texas Edwards Aquifer

Global climate change portends shifts in water demand and availability which may damage or cause intersectoral water reallocation in water short regions. This study investigates effects of climatic change on regional water demand and supply as well as the economy in the San Antonio Texas Edwards Aquifer region. This is done using a regional model which portrays both hydrological and economic activities. The overall results indicate that changes in climatic conditions reduce water resource availability and increase water demand. Specifically, a regional welfare loss of $2.2–$6.8million per year may occur as a result of climatic change. Additionally, if springflows are to be maintained at the currently desired level to protect endangered species, pumping must be reduced by 9–20% at an additional costof $0.5 to $2 million per year.     

北京市能源系统气候变化脆弱性分析与适应建议

1951-2014年,北京市年平均气温以0.37℃/10a的速度上升,且热岛效应强度和范围增大。随着北京城市化发展,气候变化给北京市能源系统带来的额外压力也趋于显著。本研究着重分析了气候变化条件下能源系统的脆弱性。研究结果表明,气候变化下北京市能源系统的脆弱性主要表现在高温天气条件下,电力需求负荷超过电力供应系统设计最大负荷;低温条件下,天然气供应短缺;极端天气给能源生产、能源供应和能源运输造成威胁。针对北京市能源系统的脆弱性,借鉴国际经验,提出了北京市能源系统提升气候变化适应能力的短期战略和长期战略,并分别从政策、技术和管理方面提出了短期战略的适应建议。     

昆明城市热岛效应立体分布特征

利用低纬高原城市昆明城内外垂直观测资料，探讨了低纬高原城市的城市气候立体分布特征，通过比较分析，得出如下初步结果：昆明城市热岛效应不仅在地面附近存在，而且在城市上空也存在；其城市热岛效应为夜间强，影响高度高（＞50m)；昼间弱，影响高度低（＜50m)；近地面强，上空弱；昆明城市区域的气温垂直分布昼间为随高度增高温度递减，而夜间为逆温分布；受昆明城市周边环境影响，昆明城市热岛效应最大值中心呈现随高度增高而偏多现象。如此的气温立体空间分布，将对城市污染扩散、建筑物的设计、城市节能等产生影响。     

Effects of projected climate change on energy supply and demand in the Pacific Northwest and Washington State

Climate strongly affects energy supply and demand in the Pacific Northwest (PNW) and Washington State (WA). We evaluate potential effects of climate change on the seasonality and annual amount of PNW hydropower production, and on heating and cooling energy demand. Changes in hydropower production are estimated by linking simulated streamflow scenarios produced by a hydrology model to a simulation model of the Columbia River hydro system. Changes in energy demand are assessed using gridded estimates of heating degree days (HDD) and cooling degree days (CDD) which are then combined with population projections to create energy demand indices that respond both to climate, future population, and changes in residential air conditioning market penetration. We find that substantial changes in the amount and seasonality of energy supply and demand in the PNW are likely to occur over the next century in response to warming, precipitation changes, and population growth. By the 2040s hydropower production is projected to increase by 4.7–5.0% in winter, decrease by about 12.1–15.4% in summer, with annual reductions of 2.0–3.4%. Larger decreases of 17.1–20.8% in summer hydropower production are projected for the 2080s. Although the combined effects of population growth and warming are projected to increase heating energy demand overall (22–23% for the 2020s, 35–42% for the 2040s, and 56–74% for the 2080s), warming results in reduced per capita heating demand. Residential cooling energy demand (currently less than one percent of residential demand) increases rapidly (both overall and per capita) to 4.8–9.1% of the total demand by the 2080s due to increasing population, cooling degree days, and air conditioning penetration.     

成都地区城市化对气候影响的模拟研究

为了研究成都地区城市化对当地气候的影响,利用不同时期的下垫面土地利用类型数据和耦合单层城市冠层模型(UCM)的WRF（Weather Research and Forecasting）模式对成都夏季和冬季城市化效应进行了模拟研究,得到以下主要结论:1）成都地区城市化使夏季城区上空出现增温区域。城区地表气温升高约2.8°C,边界层高度升高约150 m,冬季地表气温平均升高约0.6°C,边界层高度升高约25 m。夏冬两季气温日较差均减小。2）受城市化影响,成都地区夏季和冬季2 m相对湿度减小,感热通量增加,潜热通量减小,且夏季变化程度强于冬季。3）城市化使地表的粗糙度增加,进而使夏季和冬季风速在城区减小,减小约0.1~0.6 m s?1,但夏季风速减小区域较冬季更大。城市化还使城市上空低层散度减小,辐合作用增强,垂直速度增大,夏季水汽往高层输送明显。4）夏季,城市化作用使日平均和白天时段降水量在城区的迎风区和下风区均增加,夜间降水量在下风区域增加,对迎风区域影响不明显。     

气候变化与城市全要素生产率：理论与实证

利用1994—2014年中国城市数据探讨气候变化对城市全要素生产率（TFP）的影响。研究发现：气候变化（气温变化和降水量变化）对城市TFP均有负面影响,其中降水量的影响更显著,但对中国东部地区城市的TFP影响不明显;经济发展水平越高的城市,其TFP受气候变化的影响越小,而经济发展水平越低,这种影响就越显著;城市产业结构越趋合理,天气与气候的影响越低,反之则影响越大。其中降水量的变化对三大产业都有影响,对第一产业影响最显著。