CURRENT GLOBAL AGRICULTURAL SCENARIO AND PROJECTED CLIMATE CHANGE IMPACTS ON FOOD SECURITY IN THE LATE TWENTYFIRST CENTURY

摘要

Earth's atmospheric temperature fluctuations, quite a number of times over some of the past geological periods have been attributed to certain natural events and causes. The ongoing phase of global warming owes its origin to the industrial revolution of the mid-18th century and is thus predominantly anthropogenic with progressively increasing emissions of greenhouse gases projected to become double of the preindustrial level of 280 parts per million (ppm) by the year 2085 or so. As a result, global temperature is likely to rise by around 3° Celsius with large latitudinal and regional deviations, by that time. The computerized general circulation models (GCMs) popularly known as climate models, besides projecting quantitative changes in temperature, have also predicted that, in general, tropical areas would have increased mean precipitation (with regional deviations), most of the subtropical areas would have decreased mean precipitation while in the high latitudes precipitation would increase; erratic behaviour of the pattern of precipitation would be a matter of concern especially in the tropical and subtropical regions.