The El Niño weather phenomenon is emerging in the Pacific Ocean, which will affect the climate around the world in the coming weeks. "There is a real possibility that this will be the strongest El Niño in 140 years", says Paul Roundy of the State University of New York.
The effects will be felt at least until winter
The World Meteorological Organization expects that weather conditions characteristic of El Niño will soon begin to be felt, and this will last at least until winter. Depending on the intensity and duration of the phenomenon, it can lead to droughts, floods, heat waves and disruptions in food and water supplies in many regions.
UN Secretary-General Antonio Guterres warned: "Climate conditions associated with El Niño will act as a catalyst for fires in a warming world".
From drought and heat to extreme floods
El Niño is a natural climate phenomenon that occurs every two to seven years. It is caused by the weakening of winds over part of the Pacific Ocean, which leads to the accumulation of warm water. This warming occurs in only one region, and the warmed area is about the size of the United States, but the consequences are felt around the world.
However, the effects are different. In some places, droughts occur, in others, floods. Parts of Central America, Asia, Africa and Australia are becoming hotter and drier. Water shortages there are affecting agriculture, energy supplies and access to drinking water. Tegucigalpa, the capital of Honduras, has already declared a state of emergency.
In parts of the South American Pacific coast, El Niño could bring torrential rains and devastating floods. Scientists are warning of forest fires in Australia, Canada, the United States and the Amazon rainforest. Damage could run into billions.
Harvests in many places will be affected
El Niño also affects tropical storms. Scientists expect this year's Atlantic hurricane season to be weaker than usual. "When El Niño develops, especially during hurricane season, the formation of clouds, thunderstorms, rainfall and tropical cyclones in the Atlantic Ocean is usually suppressed", explains climatologist Brian Tang.
However, fewer storms does not necessarily mean less danger. Once a storm reaches hurricane strength, it is already difficult to control, which means that those hurricanes that do form can still cause catastrophic damage. In the Pacific, El Niño usually has the opposite effect. Here, the phenomenon leads to the formation of more storms that become stronger.
Marine ecosystems are also under pressure. El Niño-induced warming water temperatures can cause coral bleaching and further stress reefs that are already weakened by heat stress from climate change.
Farmers are also feeling the effects. In India, mango growers reported a dramatic drop in their harvest after unusual weather conditions hampered fruit flowering and development.
Cumulative effect with climate change
Scientists have no evidence that climate change is making El Niño stronger, but the phenomenon is accelerating its effects. "Because of climate change, an El Niño-induced drought can become an extreme drought," said Michael McFadden of the U.S. National Oceanic and Atmospheric Administration. El Niño could push average temperatures, which have been rising steadily in recent years, to new record highs.
The phenomenon has been building for months, allowing for some preparation. Forecasts allow authorities to take measures to protect crops, improve flood protection and optimize early warning systems. "We know where it will be unusually wet or dry", says McFadden. "Thanks to long-range weather forecasts, there is plenty of time to develop strategies to limit the damage," he adds.
Author: Josh Axelrod