Solution:The recent increase in the frequency of the El Niño Southern Oscillation (ENSO) can be attributed to global warming. The El Niño current, also known as the countercurrent, flows north to south, 180 km west of the Peruvian coast of South America. It extends from 3° south to 18° south latitude. El Niño is a warm current that, upon its arrival, increases ocean water temperatures by 3°-4° Celsius above normal.