El niño is back


El Niño was expected last year but it was a no-show. It finally happened on March 2015 according to scientists at the National Oceanic and Atmospheric Administration.

El Niño is part of a weather pattern divided in two phases. El Niño is the warm phase. The cold phase of this oscillation is called La Niña. El Niño occurs when Indonesian warm water around Indonesia shifts to the Eastern Pacific. Consequently, temperatures in the Eastern Pacific rise from 5 to 6 degrees Celsius above average. This phenomenon can have dangerous consequences such as thunderstorms, floodings, cyclones or droughts.

The last major El Niño event occurred in 1997-1998 and claimed around 23.000 lives worldwide and caused from 34 to 36 billion dollars in damages. Its effects are felt all around the globe and it “releases a ton of energy and can have a huge domino effect” says Michelle L’Heureux. It can deeply impact agriculture and food security. For example wheat crops in Australia have been particularly affected by El Niño in the past.

Currently El Niño is still weak to moderate. Scientific data shows that the subsurface ocean temperatures in the “Niño 34” area –center of Indian Ocean- has been at least 0.5C above average. El Niño happens later than usual and its odds to continue through the entire summer are 50 to 60% according to NOAA. It means that El Niño is less likely to deeply affect weather conditions. However, 2014 is the warmest year ever recorded despite El Niño’s absence. El Niño means higher temperatures than average because of the warmth transfer from the Ocean up to the atmosphere. Consequently, El Niño makes it more likely that 2015 will beat 2014 record. This should be another incentive towards policymakers to find an agreement at Paris in December 2015 for the COP21.