INSUBCONTINENT EXCLUSIVE:
Countries around the world from China to the United States are battling heatwaves, with the onset of the climate phenomenon El Nino helping
push temperatures higher.Scientists told Reuters that climate change and El Nino are the major drivers of extreme heat that have seen
temperature records broken in Beijing and Rome, while leaving some 80 million Americans under excessive heat warnings.El Nino is a natural
phenomenon that in addition to contributing to higher temperatures in many parts of the world, also drives tropical cyclones in the Pacific
and boosts rainfall and flood risk in parts of the Americas, Asia and elsewhere.In June, the United States National Oceanic and Atmospheric
Administration (NOAA) declared that an El Nino is now under way
The past three years have been dominated by the cooler La Nina pattern.Scientists have warned that this year looks particularly worrying
The last time a strong El Nino was in full swing, in 2016, the world saw its hottest year on record
Meteorologists expect that this El Nino, coupled with excess warming from climate change, will see the world grapple with record-high
temperatures.Experts are also concerned about what is going on in the ocean
An El Nino means that waters in the Eastern Pacific are warmer than usual
Globally, sea temperatures hit new records for the months of May and June, according to the European Union&s Copernicus Climate Change
That could supercharge extreme weather, Reuters reported.We&re in unprecedented territory,& said Michelle L&Heureux, a meteorologist with
NOAA&s Climate Prediction Center.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, shrinking GDP as extreme weather decimates agricultural production, manufacturing, and helps spread
disease.Governments in vulnerable countries are taking note
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.WHAT CAUSES AN EL NINO?
El Nino is a natural climate pattern borne out of
unusually warm waters in the eastern Pacific.It forms when the trade winds blowing east-to-west along the equatorial Pacific slow down or
reverse as air pressure changes, although scientists are not entirely sure what kicks off the cycle.Because the trade winds affect the
sun-warmed surface waters, a weakening causes these warm western Pacific waters to slosh back into the colder central and eastern Pacific
basins.During the 2015-16 El Nino — the strongest such event on record — anchovy stocks off the coast of Peru crashed amid this warm
And nearly a third of the corals on Australia&s Great Barrier Reef died
In too-warm waters corals will expel living algae, causing them to calcify and turn white.This build-up of warm water in the eastern Pacific
also transfers heat high into the atmosphere through convection, generating thunderstorms.When El Nino moves that warm water, it moves where
thunderstorms happen,& said NOAA meteorologist Tom DiLiberto
&That&s the first atmospheric domino to fall.HOW DOES EL NINO AFFECT THE WORLD&S WEATHER?
This shift in storm activity affects the current
of fast-flowing air that moves weather around the world — called the subtropical jet stream — pushing its path southward and
straightening it out into a flatter stream that delivers similar weather along the same latitudes.If you&re changing where the storm highway
goes … you&re changing what kind of weather we would expect to see,& DiLiberto said.During an El Nino, the southern United States
experiences cooler and wetter weather, while parts of the United States West and Canada are warmer and drier.Hurricane activity falters as
the storms fail to form in the Atlantic due to changes in the wind, sparing the United States
But 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.El Nino could offer a reprieve to the Horn of Africa, which recently suffered five consecutive failed rainy seasons
El Nino brings more rain to the Horn, unlike the triple-dip La Nina, which desiccated the region.Historically, both El Nino and La Nina have
occurred about every two to seven years on average, with El Nino lasting 9 to 12 months
La Nina, which takes hold when waters are cooler in the Eastern Pacific, can last one to three years.IS CLIMATE CHANGE AFFECTING EL
NINO?
How climate change might be affecting El Nino is &a very big research question,& said DiLiberto
While climate change is doubling down on the impacts from El Nino — layering heat on top of heat, or excess rainfall on top of excess
rainfall — it&s less clear if climate change is influencing the phenomenon itself.Scientists are not sure whether climate change will
shift the balance between El Nino and La Nina, making one pattern more or less frequent
If ocean temperatures are rising across the board, it is unlikely the cycle would change, scientists said, as the basic mechanics behind the
phenomenon stay the same.However, if some parts of the ocean are warming faster than others, that could influence how El Nino plays out by
amplifying temperature differences.The post Explainer: How El Nino is helping drive heatwaves and extreme weather first appeared on Ariana
