Agrometeorological adaptation strategies to increasing climate variability and climate change

This paper starts with summarizing the indications for climate change as they are reviewed in the most recent WMO global climate system reviews. There are indications in the paper for increasing climate variability in certain areas. Some of the principal causes of increasing climate variability and climate change (ICV & CC) are a mixture of external and internal factors to the climate system. Of changes over the past century, increases in greenhouse gases have probably been the most important cause of climate change. Continued warming of global climate is expected to occur if atmospheric greenhouse gases keep increasing, with global climate models projecting an increase in mean temperature by 1-3 degrees C by 2100 A.D. Upon these general background trends interannual climate variability has operated. Volcanic eruptions that inject significant amounts of sulphate aerosols into the stratosphere cause a cooling of global climate in the order of 0.5 degrees C for a period of 12-24 months. The ENSO (El Nino/Southern Osciallation) is the major cause of climate variability on seasonal to interannual time scales. Since 1976 El Nino episodes of the Southern Oscillation have increased in frequency, and become more extreme. There has yet been little analysis of short-term extreme events, such as high intensity rainfall, tropical storms, tornadoes, high winds, extreme temperatures and droughts to show if the frequency and intensity of these have changed. However, for some of these events in some areas an increase is occurring while in other areas no changes have currently occurred. Changes in extremes cause significant impacts on agriculture. Strategies to fight slower variations have already been widely proposed and require application. Agrometeorologists can assist the agricultural community in developing strategies to adapt to ICV & CC that should be validated on-farm for improved extension advisories, together with fanners. To enhance adaptation and promote sustainable development, strategic planning studies for assessment of natural resources, technological change and innovation are required to increase productivity, with sustainable economic growth that preserves finite natural resources. The ten most essential agricultural umbrella projects with agrometeorological priority components in the literature that either modify the consequences of ICV & CC and/or mitigate their causes have been selected. The Commission for Agricultural Meteorology has pledged to guide the implementation of projects that assist adaptation strategies to ICV & CC within the WMO Agrometeorological Programme. (C) 2000 Elsevier Science B.V. All rights reserved.