Scientists declare the beginning of El Niño – 06/08/2023 – Environment

US scientists declare the beginning of El Niño this Thursday (8). According to the National Oceanic and Atmospheric Administration (NOAA), the ocean and atmosphere conditions that characterize the climate phenomenon have been confirmed, and pave the way for possible temperature records in 2024.

El Niño is marked by above-average warming in the Pacific Ocean near the equator. It changes the circulation of the trade winds, which run from east to west, carrying moisture and warmer waters from the coast of the Americas to Asia and Oceania.

Despite taking place in the Pacific, its effects reach other regions of the planet. Some are the general rise in temperatures, increased rainfall or drought in different regions, coral bleaching and even damage to the economy. An example is the impact of the lack of rain, which harms crops. Another is in the fishing activity.

This is because, with the normal westward movement of warm water, deeper, colder water “rises”. This movement is called upwelling, which renews nutrients and is essential for marine fauna off the coast of South America. With El Niño, this does not happen.

El Niño occurs every two to seven years, and is an old phenomenon, with references going back to the 19th century, and has nothing to do with human activity. But it is associated, for example, with temperature records.

One of the main recent milestones was the extreme drought between 2015 and 2016, associated with a “super El Niño”, which caused the biggest fire recorded in the Amazon in Roraima. In a few weeks, the state lost 14,000 km² of forest.

In Brazil, the most common effects are more chance of drought in the North and Northeast. Climate change, in turn, adds an extra concern to the scenario for the coming months by making environments like the Amazon more susceptible to these big fires, which can degrade the forest beyond deforestation.

In the South, El Niño alters the circulation of winds, which form a barrier and prevent cold fronts from the southern hemisphere from circulating across the country. As they remain longer over the region, the frequency of heavy rains increases there.

The NOAA statement does not speak of an extreme El Niño like the one eight years ago, but the probabilities are 84% for a moderate and 56% for a strong one at the beginning of winter in the northern hemisphere, in December.

In May, the World Meteorological Organization, a specialized agency of the UN, declared that there is a 98% chance that global temperatures will reach records in the next five years, and that the probability that this increase exceeds 1.5ºC in relation to the pre-war period industrial is 66%.