tailieunhanh - Climate Change and Global Food Security - Section 2

Trong khi cuộc cách mạng xanh trong phần sau của 20 thế kỷ có thể đã được tạo điều kiện thuận lợi giống lúa có năng suất cao hơn, tác động của kỹ thuật khai thác tăng nước (đập, hệ thống thủy lợi) vào sản xuất nông nghiệp có thể không được bỏ qua. Thúc đẩy sản xuất nông nghiệp để cô lập carbon sẽ yêu cầu đánh giá cẩn thận của nguồn nước trong tương lai. Sau đây được cho là tác động đến chu kỳ nước trong một khí hậu trong tương lai: (1) các loại khí gây hiệu ứng nhà kính (GHGs) như. | Section II Climate Change and Net Primary Productivity 2005 by Taylor Francis Group LLC 6 Climate Change Effects on the Water Supply in Some Major River Basins RANJAN S. MUTTIAH AND RALPH A. WURBS CONTENTS Two Basins in Ten Major Basins of the INTRODUCTION While the Green Revolution during the latter part of the 20th century may have been facilitated by higher-yield grain varieties the impact of increased water harvesting techniques 147 2005 by Taylor Francis Group LLC 148 Muttiah and Wurbs dams irrigation systems on agricultural production cannot be ignored. The promotion of agriculture to sequester carbon will require the careful evaluation of future water availability. The following are widely thought to impact the water cycle in a future climate 1 greenhouse gases GHGs such as CO2 CH4 and N2O are expected to increase from human related activities such as fuel emission and fertilizer application 2 air and sea surface temperatures SST will rise due to GHGs 3 the number of extreme events flooding drought tornados due to SST-related El Nino Southern Oscillation ENSO events precipitation intensity may increase that is the wet periods will get wetter and the dry periods will get drier 4 the quality of arable land may decline due to increased salinization erosion and poor management and 5 urban population growth will continue at or above current rates. Iraq serves as an example of point 4. While about million ha are potentially cultivable in irrigated agriculture roughly half million ha are actually cultivated due to water logging and salinization problems Food and Agriculture Organization FAO 1997 . Recent extreme events from the late 1990s to the present such as the flooding of the Elbe in Central Europe in August 2002 the 1998 flooding of the Yangzte in China the 2000 and 2002 droughts in .