广东气候变化评估报告(节选)

IPCC第4次报告指出:近100年全球平均气温升高了0.74℃,最近50年有加速之势,而且很可能主要由人类活动引起;预计21世纪,全球仍将表现为明显的增温,极端天气气候事件及其引发的气象灾害可能更加严重。近50年,广东气温升高与全球平均水平相当,其中珠江三角洲地区是主要增温区域,其次是东南部沿海地区。预计广东在2011~2040年、2041~2070年和2071~2100年的年平均气温可能分别升高约1.0、1.9和2.8℃。在全球变暖的背景下,广东地区气候变化的特征主要表现在:降水变率加大,旱涝灾害频繁;登陆台风的个数减少,初台登陆时间异常;高温日数增加,高温酷热、热浪愈发频繁;低温日数减少,暖冬突出;极端最低气温变化不稳定性增加,寒冷灾害加重;灰霾天气增多,日照时数减少;极端天气气候事件及其引发的气象灾害造成的经济损失显著增大。广东近50年的增暖在很大程度上可能归因于温室气体浓度增加造成的温室效应,这种温室效应已经对增暖做出了实质性的贡献;城市化导致的热岛效应加剧了局部地区的气温上升。气候变暖既有负面影响也有正面影响,但负面影响可能超过正面影响。气候变暖将导致海平面上升,继而可能对广东沿海低洼地区带来严重的负面影响。在过去近100年全球海平面上升约10~20 cm,广东海平面上升速率为1.7 mm/年,海平面上升会使海岸侵蚀加重,咸潮海水入侵加剧;温度上升可能使广东近海珊瑚礁生态系统退化,且变得更加脆弱;珠江口的咸潮上溯的现象可能更加频繁;广东沿海的赤潮可能更加频发。气候变暖将导致农业生产的不稳定性增加,产量波动大,农业成本和投资将增加。此外,气候变化对我省国民经济的一些方面(如水资源、人类健康、人类居住环境、保险和其它金融业)的影响可能以负面为主。为适应和减缓气候变化的影响,建议:通过节能降耗,减缓温室气体排放;采取措施,适应已经发生了变化的气候;提高对气候系统的监测能力;加强气候变化领域的科学研究、适应对策研究及技术开发;在经济社会发展规划中统筹考虑应对气候变化问题;提高公众的气候保护意识;加大资金投入;积极开展合作与交流。     

21世纪新疆区域气候暖湿化趋势预估分析

新疆未来暖湿化的预估分析可为区域气候变化减缓和适应提供重要的科学基础。国际耦合模式比较计划第六阶段（CMIP6）全球气候模式在三种共享社会经济路径（SSPs）下的结果显示,新疆地区未来2021~2100年总体呈现气温升高、降水增加的“暖湿化”现象,但这种变化的具体数值和空间分布存在一定差异。其中SSP2-4.5情景下,相对于1995~2014年,预估2021~2040年新疆地区年平均气温将升高1.2℃左右,年平均降水将增加6.8%。对极端事件的预估结果表明,新疆地区未来暖事件将增加,冷事件将减少;极端强降水事件将增多,且高排放情景下的增加更为显著。新疆地区的未来预估分析,将有助于对新疆地区灾害风险时空变化格局的认识,对未来农业方面等风险防范也有重要的指示作用。     

Past and Future Changes in the Climate of Hong Kong

Over the years, the Hong Kong Observatory has carried out scientific studies to evaluate the observed climate trends and project the future climate in Hong Kong. Analysis of the meteorological observations at the observatory's headquarters in Tsim Sha Tsui since 1885 reveals that the temperature rise in Hong Kong during the past 124 years is in accord with the global rising trend. The accelerated rising trend in the mean temperature in last few decades may be attributed to the anthropogenic influences, especially urbanization. A similar increasing trend is also observed for rainfall. Other observations such as increasing cloud amount and decreasing total global solar radiation are all consistent with the global trend. Studies of past occurrences of extreme temperature and rainfall have also been carried out. The results indicate that cold episodes have become rarer while very hot days and heavy rain events are becoming more frequent. The observatory also makes use of the data from the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) and employs statistical downscaling techniques to carry out projections of temperature and precipitation in the 21st century. It is found that the rise in temperature in Hong Kong will be slightly higher than the global mean in the 21st century. The annual rainfall in Hong Kong is also expected to rise by the end of the 21st century, so is its year-to-year variability.     

Statistical Projections of Ocean Climate Indices off Newfoundland and Labrador

ABSTRACT

Present global climate models (GCMs) are unable to provide reliable projections of physical oceanographic properties on the continental shelf off Newfoundland and Labrador. Here we first establish linear statistical relationships between oceanographic properties and coastal air temperature based on historical observations. We then use these relationships to project future states of oceanographic conditions under different emission scenarios, based on projected coastal air temperatures from global (Canadian Earth System Model, version 2 (CanESM2), Geophysical Fluid Dynamics Laboratory's Earth System Model, version 2M (GFDL-ESM2M)) and regional (Canadian Regional Climate Model (CRCM)) climate models. Estimates based on CanESM2 agree reasonably well with observed trends, but the trends based on two other models result in substantial underestimates. Projected trends are closer to observations under a high emission scenario than under median-level emission scenarios. Over the next 50 years, the increases in projected sea surface temperature off eastern Newfoundland (Station 27) range from 0.4° to 2.2°C. The increases in bottom ocean temperature over the Newfoundland and Labrador Shelves range from 0.4° to 2.1°C. The area of the cold intermediate layer (<0°C) on the Flemish Cap (47°N) section is projected to decrease by 9–35% of the 1981–2010 average. The decline in sea-ice extent off Newfoundland and Labrador ranges from 20 to 77% of the average (0.4–1.5?×?10⁵?km²), and the reduction in the number of icebergs at 48°N off Newfoundland ranges from 30% to nearly 100% of the norm at this latitude. Despite differences among the models and scenarios, statistical projections indicate that conditions in this region will reach or exceed their maxima (sea surface temperature, bottom ocean temperature) and reach or fall below their minima (sea-ice extent, number of icebergs) that were observed during the course of monitoring activities over the past 30–60 years, possibly as early as 2040. We note, however, that the statistical relationships based on historical data may not hold in the future because of the changing influence of input from Arctic waters and because of large uncertainties in projected air temperatures from GCMs.     

REVIEWS OF GEOGRAPHIC SOFTWARE

Reviews of geographic software in this article: GEOGRAPHY MACCHORO OPS83 Population Analysis on Microcomputers with PC or MS DOS STATPAC GOLD THUNDERSCAN     

THE GEOGRAPHY OF MASTODON EXTINCTION

Geographic Software Reviewed in this article:

LIFE TABLES and the LESLIE MATRIX. CONDUIT

MENTMAP2. Lawrence W. Carstensen Jr.

PC-MATLAB, Version 1.0. The Math Works, Inc.

QUICKMAP, version 1.0. Sammamish Data Systems, Inc.

SYSTAT: THE SYSTEM FOR STATISTICS, Version 2.1, Systat Inc.

USA DISPLAY. Instant Tecall     

SOFTWARE REVIEWS

Electromap World Atlas , Version 1.1. Interactive Population Statistical System , Version 1.0. Jerry W. Wicks and Jose Luiz Pereira de Almeida MATHCAD , Version 2.5. Memory Mate. Micro DEM +, Version 5.21. Peter Guth NCSS – Number Cruncher Statistical System , Version 5.02. Dr. Jerry L. Hintze     

METPET: Metamorphic petrology microcomputer programs

METPET is a package of three interactive microcomputer (IBM PC or compatible) programs. FILEMAN is a utility program to create, edit and print 'composition files', i.e. files containing the records of chemical compositions of minerals or rocks, expressed in terms of primary chemical components. PROJECT recalculates selected compositions in terms of new ( secondary ) components. It then projects these compositions onto a subspace defined by two, three or more of the secondary components, first giving a plot on the screen and then, if requested by the user, on a selected graphic device. REACT calculates a possible set of independent reactions between a set of phases, whether pure compounds or solutions. Any linear combination of the independent reactions can be calculated on request.     

An iterative approach for inverse transformation of map projections

ABSTRACT

Map projections are given by forward transformation equations. Inverse transformation is derived from forward transformation analytically or numerically. In this paper, a numerical approach for inverse transformation of map projections is proposed, which is based on numerical differentiation and Newton–Raphson root finding method. This approach can facilitate the program developments for map projections when inverse transformation is needed. Numerical differentiation is tested with three map projections. It is seen that seven-digit precision or more can be reached. Boundary conditions and initial guess problem in inverse transformation are discussed. In terms of initial guess, map projections are divided into three categories, and appropriate initial guess values for cylindrical, pseudocylindrical, azimuthal, and conical projections in normal aspect are suggested. Newton–Raphson method with numerical differentiation is tested with 20 different map projections by using test data sets. The results show that the proposed approach is applicable if appropriate initial guess is available.     

The accountability imperative for quantifying the uncertainty of emission forecasts: evidence from Mexico

Governmental climate change mitigation targets are typically developed with the aid of forecasts of greenhouse-gas (GHG) emissions. The robustness and credibility of such forecasts depends, among other issues, on the extent to which forecasting approaches can reflect prevailing uncertainties. We apply a transparent and replicable method to quantify the uncertainty associated with projections of gross domestic product growth rates for Mexico, a key driver of GHG emissions in the country. We use those projections to produce probabilistic forecasts of GHG emissions for Mexico. We contrast our probabilistic forecasts with Mexico’s governmental deterministic forecasts. We show that, because they fail to reflect such key uncertainty, deterministic forecasts are ill-suited for use in target-setting processes. We argue that (i) guidelines should be agreed upon, to ensure that governmental forecasts meet certain minimum transparency and quality standards, and (ii) governments should be held accountable for the appropriateness of the forecasting approach applied to prepare governmental forecasts, especially when those forecasts are used to derive climate change mitigation targets.

POLICY INSIGHTS

• No minimum transparency and quality standards exist to guide the development of GHG emission scenario forecasts, not even when these forecasts are used to set national climate change mitigation targets.

• No accountability mechanisms appear to be in place at the national level to ensure that national governments rely on scientifically sound processes to develop GHG emission scenarios.

• Using probabilistic forecasts to underpin emission reduction targets represents a scientifically sound option for reflecting in the target the uncertainty to which those forecasts are subject, thus increasing the validity of the target.

• Setting up minimum transparency and quality standards, and holding governments accountable for their choice of forecasting methods could lead to more robust emission reduction targets nationally and, by extension, internationally.