Agrometeorological adaptation strategies to increasing climate variabilityand climate change

This paper starts with summarizing the indications for climate change as th ey 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 greenho use gases have probably been the most important cause of climate change. Co ntinued warming of global climate is expected to occur if atmospheric green house gases keep increasing, with global climate models projecting an incre ase in mean temperature by 1-3 degrees C by 2100 A.D. Upon these general ba ckground trends interannual climate variability has operated. Volcanic erup tions that inject significant amounts of sulphate aerosols into the stratos phere 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 ma jor cause of climate variability on seasonal to interannual time scales. Si nce 1976 El Nino episodes of the Southern Oscillation have increased in fre quency, and become more extreme. There has yet been little analysis of short-term extreme events, such as hi gh intensity rainfall, tropical storms, tornadoes, high winds, extreme temp eratures 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 occ urring while in other areas no changes have currently occurred. Changes in extremes cause significant impacts on agriculture. Strategies to fight slow er variations have already been widely proposed and require application. Ag rometeorologists can assist the agricultural community in developing strate gies to adapt to ICV & CC that should be validated on-farm for improved ext ension advisories, together with fanners. To enhance adaptation and promote sustainable development, strategic planni ng studies for assessment of natural resources, technological change and in novation are required to increase productivity, with sustainable economic g rowth that preserves finite natural resources. The ten most essential agric ultural umbrella projects with agrometeorological priority components in th e literature that either modify the consequences of ICV & CC and/or mitigat e their causes have been selected. The Commission for Agricultural Meteorol ogy has pledged to guide the implementation of projects that assist adaptat ion strategies to ICV & CC within the WMO Agrometeorological Programme. (C) 2000 Elsevier Science B.V. All rights reserved.