Warnings of a powerful El Nino weather pattern this year indicate that we may soon face drought, flooding and extreme heat. What effects are expected? And can we get ready for the worst-case scenario?
A potentially strong El Nino developing in the Pacific Ocean could alter weather patterns globally in the coming weeks. Forecasters caution that this could rank among the most intense El Nino events ever recorded.
There is "real potential for the strongest El Nino event in 140 years," stated Paul Roundy, a professor of atmospheric and environmental sciences at the State University of New York at Albany.
The World Meteorological Organization (WMO) anticipates that El Nino conditions will emerge shortly and persist at least into winter. Depending on its intensity and duration, this climate phenomenon could trigger drought, flooding, heat waves and disruptions to food and water supplies in various regions.
"The world must treat it as the urgent climate warning it is," said United Nations Secretary-General Antonio Guterres. "El Nino conditions will pour fuel on the fire of a warming world."
What is El Nino?
El Nino is a natural climate pattern that occurs every two to seven years. It starts when trade winds over the tropical Pacific weaken, allowing warm water to build up in the Pacific Ocean.
Although the warming area is roughly the size of the continental United States and happens only in one region, its impacts can be felt worldwide.
"By changing the tropical atmosphere, you can then change the atmosphere further away across the mid-latitudes, which is why we care about it so much, even though we're thousands and thousands of miles away potentially," said NASA Goddard Institute for Space Studies Director Gavin Schmidt to DW.
This initiates a global chain reaction, with El Nino being "the first atmospheric domino to fall," he added.
What impacts are expected on the climate?
These reactions vary significantly from region to region. In some areas, that means a heightened risk of drought; in others, flooding.
Parts of Central America, Asia, Africa and Australia often become hotter and drier during El Nino years. The resulting water shortages can impact agriculture, hydropower generation and drinking water supplies. In Honduras, authorities estimate that around 75 municipalities could face severe drought conditions. Tegucigalpa, the country's capital, has already declared a water emergency.
In other parts of the world, the risks are reversed. Along portions of South America's Pacific coast, El Nino can bring torrential rainfall and devastating flooding.
The consequences can last long after the rain stops or reservoirs run dry. El Nino has been linked to crop failures and economic losses potentially reaching trillions. During the 2015-2016 El Nino, poor harvests left millions of people globally in need of food assistance.
Wildfires are also a growing concern. Scientists warn that El Nino is likely to raise the risk of severe heat and drought conditions that fuel fires across Australia, Canada, the United States and the Amazon rainforest.
Storms, reefs and the Atlantic hurricane season
El Nino plays a major role in tropical storm activity.
Scientists expect this year's Atlantic hurricane season to be less active than average. El Nino conditions tend to increase wind shear over the Atlantic, making it harder for storms to form and strengthen.
"The waters are beginning to warm in the central and eastern tropical Pacific," said atmospheric scientist Brian Tang. "Usually when we have an El Nino developing, especially during hurricane season, that suppresses clouds, thunderstorms, precipitation and tropical cyclones in the Atlantic."
But fewer storms don't necessarily mean less danger. Once a storm reaches hurricane strength, it becomes harder to suppress, meaning those that do form could still cause catastrophic damage.
El Nino threatens to make the world even hotter
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The situation is different in the Pacific, where El Nino tends to have the opposite effect, fueling more and stronger storms.
Marine ecosystems are also under strain. Warmer ocean temperatures associated with El Nino can cause coral bleaching and add pressure to reefs already weakened by repeated heat stress linked to climate change.
Agriculture is also affected. In India, mango growers have reported sharply reduced harvests after unusual weather conditions disrupted flowering and fruit development, impacting both supply and income for producers.
How does climate change affect El Nino?
Scientists say there is no clear evidence that climate change is making El Nino itself stronger. But climate change can amplify its effects.
"Climate change can make a severe El Nino drought into an extreme El Nino drought," said Michael McPhaden, a senior scientist at the National Oceanic and Atmospheric Administration.
A warmer atmosphere holds more moisture, increasing the risk of extreme rainfall and flooding. Higher temperatures can also intensify drought by drying soils more quickly.
Because global temperatures are already near record highs, El Nino events can more easily push global temperatures into new record territory.
Can countries prepare for this El Nino?
One advantage of El Nino is that it develops gradually and can be monitored months ahead.
Scientists can track ocean temperatures and atmospheric conditions, giving governments and communities time to prepare.
Forecasts can help authorities protect harvests, strengthen flood defenses and improve early warning systems.
"We know where it will be unusually wet or dry," McPhaden said. "There's plenty of time through these long-range weather forecasts to develop mitigation strategies to avoid some of the worst impacts."
Edited by: Sarah Steffen
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