《全球气候变化现状及对策 第三小组.doc》由会员分享，可在线阅读，更多相关《全球气候变化现状及对策 第三小组.doc（8页珍藏版）》请在金锄头文库上搜索。
1、气候变化的现状联合国政府间气候变化专门委员会(IPCC)第4次评估报告再次确认了全球气候变化事实：到2005年止，与100年前相比，全球平均气温已经升高了074。报告称，目前地球产生温室效应的气体比过去1万年中任何一段时期都高，大气中二氧化碳的含量比过去65万年中任何时候都高，比工业革命前高35。2007年14月，全球地表温度更是打破了自1880年以来的所有记录，平均气温比往年上升了1。因为人为加剧的温室效应，地球正在以前所未有的速度变暖。近年来，世界风暴、洪水和干旱发生的次数明显增加，异常的暴雨、降雪和严酷的热浪等灾害性天气气候事件频现。在全球变暖的大背景下，中国近百年的气候也发生了明显变化
2、，变化趋势与全球的总趋势基本一致：一是近百年来，中国年平均气温升高了0508C，略高于同期全球增温平均值，近50年变暖尤其明显，地表气温年均升高11，增暖速率为每10年022，突出体现在冬季增温、连续出现全国性暖冬和西北、华北和东北地区气候变暖。二是近50年来中国年平均降水量逐渐减少，六大江河的实测径流都呈下降趋势，而区域降水变化波动较大。中国年平均降水量平均每10年减少29毫米。华北大部分地区、西北东部和东北地区降水量平均每10年减少20-40毫米，其中华北地区最为明显；华南与西南地区降水明显增加，平均每10年增加2060毫米。三是近50年来，中国主要极端天气与气候事件的频率和强度出现了明显
3、变化。华北和东北地区干旱面积扩大，长江中下游地区和东南地区洪涝加重，农业生产的不稳定性增加。四是近50年来，中国沿海海平面年平均上升速率为25毫米，略高于全球平均水平，海岸带的极端天气事件造成的灾害更明显。五是中国山地冰川快速退缩，西北冰川面积减少了21，并有加速趋势。中国科学家的预测结果表明，中国未来的气候变暖趋势还将进一步加剧。如不能有效应对，气候变化将对生态系统造成不可恢复的影响，人类社会将面临水资源短缺、粮食安全等危机，人类健康、社会经济发展也将受到严峻挑战。联合国政府间气候变化委员会(PCC)第4次评估报告强调：对于过去50年来的全球暖化现象，人类活动要负90的责任。特别是近100年
4、来的全球气候变暖的主要原因，被普遍归结为人类过度向大气排放二氧化碳及其他温室气体的增加。气候变化与人类活动已经使生物灾害频发和生物多样性锐减，水土流失和荒漠化扩展，三江平原和青海湿地功能下降。未来气候变化将使基因多样性、物种分布和生态系统多样性改变，自然保护区功能下降，土壤侵蚀加速泥石流增加土壤肥力下降。气候变化对中国有关重大工程可能产生一定影响。气候变化可能增加长江流域上游降水，引发三峡库区泥石流，滑坡等地质灾害。气候变化对南水北调工程的影响不大，但气温升高对南水北调东线水质的影响不可忽视。未来青藏高原气温有可能变暖，青藏铁路沿线多年冻土会进一步退化，影响某些地段铁路路基的稳定性。气候变化对
5、中国6大林业重点工程的影响有利也有弊某些树种的生长率将提高但部分工程区内的宜林荒地和退耕地可能逐步转化为非宜林地“三北”地区、太行山、西南干热河谷地区的环境可能变得更为恶劣，造林更为困难。气候变化增加疾病发生和传播的机会，危害人类健康，如20世纪9 0年代拉尼娜年登陆台风次数多于厄尔尼诺年其霍乱病例数占总病例数的61，而厄尔尼诺年只占39。预计气候变化将增加心血管病厄尔尼诺、疟疾登革热和中暑等疾病发生的程度和范围。气候变化可能使雪山融化和海平面上升导致山区、海岸和海岛风景地的变迁影响自然保护区和国家森林公园等以生态环境和物种多样性为特色的旅游景点从而对自然和人文旅游资源、以及对旅游者的安全和行
6、为产生影响。中国气候的重要特点是温度变化幅度大于地球上其他同纬度地区，使得冬季采暖、夏天制冷用能的问题与同纬度国家相比更加突出。全球变暖将加剧未来中国夏季制冷的电力消费的持续增长趋势，对保障电力供应带来更大压力。Chinas Efforts in Mitigating Climate ChangeClimate change is a major global issue of common concern to the international community.As a developing country of responsibility, China is among the f
7、irst to formulate a national Agenda 21 entitled Chinas Agenda 21 - White Paper on Chinas Population, Environment and Development in the 21st Century, soon after the United Nations Conference on Environment and Development in 1992, and adopted a series of policies and measures taking into account its
8、 specific national circumstances, making positive contribution to the mitigation of climate change.1). Restructuring the economy, promoting technology advancement and improving energy efficiencyBeginning from the late 1980s, the Government of China paid more and more attention to the change of the e
9、conomic growth pattern and the restructuring of economy, and integrated the reduction of energy and other resources consumption, the promotion of clean production, and the prevention and control of industrial pollution into its national industrial policies. The industrial structure has been signific
10、antly improved through the implementation of a series of industrial policies to accelerate the development of the tertiary industry and restructure the secondary industry. Such change has brought about significant energy conservation benefits.2). Optimizing energy mix by developing low-carbon and re
11、newable energyUnder national policy guidance and with financial support, the share of high grade and clean energy was improved by strengthening the development and utilization of hydropower, nuclear energy, oil, gas and coal-bed methane , and supporting the development and utilization of new and ren
12、ewable energy including biomass, solar, geothermal and wind power in rural areas, remote areas and other suitable areas. Share of coal in Chinas primary energy mix decreased from 76.2 percent in 1990 to 68.9 percent in 2005, whereas the shares of oil, gas and hydro increased from 16.6 percent, 2.1 p
13、ercent and 5.1 percent in 1990 to 21.0 percent, 2.9 percent and 7.2 percent in 2005, respectively. 3). Launching national wide tree-planting and afforestation campaign and enhancing ecology restoration and protectionSince the reform and opening up to the outside world, tremendous achievement has bee
14、n made in tree-planting and afforestation along with the implementation of key forest ecological projects. According to the Sixth National Forest Survey, the acreage of conserved artificial forests in China was 54 million hectares, ranking the top one in the world, and the amount of growing stock wa
15、s 1505 million cubic meters. Total area of forest cover in China was 174.91 million hectares, and the percentage of forest coverage increased from 13.92 percent to 18.21 percent during the period from early 1990s to 2005. In addition to tree-planning and afforestation, China initiated many other pol
16、icies for ecology restoration and protection, including natural forest protection, reclaiming cultivated land to forest or grassland, pasture restoration and protection, further enhancing the capacity of forest as the sinks of greenhouse gas. Meanwhile, urban green area grew rapidly in China as well. By the end of 2005, total green area in the built-up urban area in the whole country reached 1.06 million hectares
