The US National Oceanic and Atmospheric Administration (NOAA) declared on Thursday that the El Nino climate pattern is now underway, bringing the threat of more frequent tropical cyclones in the Pacific, increased rainfall and flooding in parts of the Americas and rising temperatures across the globe.
El Nino and its counterpart, La Nina, are climate patterns that originate in the Pacific Ocean every two to seven years on average, and can affect weather worldwide. The past three years have been dominated by the cooler La Nina pattern, but the start of El Nino is set to bring warmer temperatures and extreme weather conditions around the globe.
The last time a strong El Nino was in full swing in 2016, the world experienced its hottest year on record.
NOAA said there is a 56 percent chance that when this El Nino peaks in strength – normally during the Northern Hemisphere winter – it will be a strong event, meaning that Eastern-Pacific sea surface temperatures will be at least 1.5C higher than normal.
“It’s too early to say how the current El Nino storyline will unfold, but if it does unleash its full power in 2024 then it’s very likely that yet another record global temperature will be breached,” said Richard P. Allan, professor of climate science at the University of Reading, UK.
Global impact
An increase in extreme weather events – from drought to cyclones – is also expected.
Typically, the southern United States experiences cooler and wetter weather during an El Nino, while parts of the US West and Canada are warmer and drier.
Tropical cyclones in the Pacific get a boost, with storms often spinning toward vulnerable islands.
Some parts of Central and South America experience heavy rainfall, although the Amazon rainforest tends to suffer from drier conditions. And Australia endures extreme heat, drought and bushfires.
First to feel the impact will be countries close to the Pacific, such as the west coast of the Americas, Japan, Australia and New Zealand, but “many remote regions are affected by El Nino too,” said Wilfran Moufouma Okia, head of the regional climate prediction services division at the World Meteorological Organisation (WMO).
“A broad pattern shows El Nino coincides with a large area of drought over Australia, the Indian Peninsula, South Africa and the northern part of South America,” Okia added. “We also see floods in the south of the US and some parts of Central Asia – those are not all regions close to the Pacific, but they are often affected the same way when there is an El Nino.”
Following announcements from weather bureaus in the US and Japan, countries are already rushing to prepare. Peru has set aside $1.06 billion to deal with El Nino's impacts and climate change, while the Philippines – at risk from cyclones – has formed a special government team to handle the predicted fallout.
Agricultural production at risk
The weather impacts may be milder in Europe.
“It is somewhat more likely that Spain, Portugal and France experience a wetter autumn, with warmer conditions more generally across much of central and southern Europe in October and November,” Allan said.
But the economic impacts of the global weather phenomenon are likely to leave their mark.
“Wide-ranging, large and often concurrent impacts across the world can certainly affect Europe indirectly through socioeconomic damage that can cause prices to rise and some goods to become scarce,” Allan added.
This year's El Nino could lead to global economic losses of $3 trillion, according to a study published last month in the journal Science. GDP levels are likely to shrink as extreme weather decimates agricultural production and manufacturing, as well as helping to spread disease.
Early signs of hot, dry weather caused by El Nino are threatening food producers across Asia, and could lead to winter crop production falling 34 percent from record highs in Australia. Rising temperatures could also impact palm oil and rice production in Indonesia, Malaysia – which between them supply 80 percent of the world's palm oil – and Thailand.
Meanwhile, American growers are counting on heavier summer rains from the weather phenomenon to alleviate the impact of severe drought.
El Nino adding to global warming
Experts are also concerned about what's going on in the ocean.
Following the last El Nino in 2016, warmer waters caused anchovy stocks off the coast of Peru to plummet and killed off nearly a third of the corals in Australia's Great Barrier Reef.
An El Nino means that waters in the Eastern Pacific are warmer than usual. But even before this El Nino began, the average global sea surface temperature was about 0.1C higher in May than any other on record. That could supercharge extreme weather.
Then there is the ongoing impact of man-made climate change.
“El Nino will add an additional warming,” said Okia.
In the next five years, there is a 66 percent chance that global temperatures will – temporarily – rise higher than the 1.5°C above pre-industrial levels limit set out in the Paris Agreement.
“That's a combination of both El Nino and global warming,” Okia said.
In past years, the cooler La Nina cycle helped to slow down warming. “Yet we still saw some extreme temperatures,” Okia said.
In the long term, the relationship between El Nino and global warming caused by human activity does not bode well.
“It is clear that the unusually wet, dry and hot weather extremes will intensify as a warmer, thirstier atmosphere can even more effectively sap water from the ground in one region and dump it as heavy rainfall in another,” Allan said.
“Climate change is amplifying El Nino impacts that include flooding, droughts, heatwaves and wildfires where and when they occur.”
(With Reuters)
