文档介绍：全球气候变化论文
全球气候变化及影响选修课结业论文论题:全球气候变化对农业的影响――以对中国农业影响为例摘要根据全球气候的变化,大气中温室气体的浓度在逐渐升高,预计2030年CO2浓度将加倍. 温室气体产生温室效应,会使大气升温,全球平均降水增加,海平面升高等,这些变化对全球农业将产生深刻影响。作物光合作用会增强,但农产品质量可能下降;土壤水分有效利用率将发生变化;农作物分布区域和面积将有大幅度变更;灾害性天气可能会增加;农业病虫害因气温升高可能会扩大危害;海平面升高会淹没一些土地,并使盐渍化扩大。在全球气候变化背景下,中国的气温不断增高,℃,明显高于全球;降水变化趋势不明显,年代际波动较大,也存在明显的地区差别;极端天气气候事件不断增多;气候变暖将使中国各类自然植被发生明显北移,土地荒漠化危Abstract According to the change of global climate, the concentration of greenhouse gases is increasing and CO2 will be doubled in 2030. The effects of greenhouse due to greenhouse gases, will increase the mean temperature, mean precipitation on the earth, and will rise in sea level. All these changes will affect agriculture significantly. The rate of photosynthesis of crop plants will go up, but the yield quality under a doubling CO2 may decrease. Soil water use by plants may change. The distribution and areas of crop s will move toward the north. The effects of drought, heat stress, storms, severe frosts etc. will increase. The distribution and intensity of harmfulness of agricultural pests and disease to the crops may be extended. Some low-lying croplands may be loss through the inundation and may increase salinity of coastal groundwater due to the higher sea level. Under the background of the global climate change, the mean temperature continues to rise in China during the last 50 years, with annual mean surf