EL NINÕ

Southern Oscillation (ENSO) refers to the combined effects of El Ninõ (see above) and a global-scale shift in atmospheric pressure called the Southern Oscillation. In the warm phase of ENSO, El Ninõ warming extends over much of the tropical Pacific and becomes clearly linked to the SO pattern. Many of the countries most affected by ENSO events are developing countries with economies that are largely dependent upon their agricultural and f:ishery sectors as a major source of food supply, employment and foreign exchange. New capabilities to predict the onset of ENSO events can thus have important human impacts. While ENSO :is a natural part of Earth's climate variability, whether its intensity or frequency may change as a result of global warming :is a concern.