El
Niño is back, and global temperature records are in danger
station surveys the bottom of a dry dam on his property on June 7, 2005, in Leigh Creek, Australia. Australia endured its worst drought in decades due to the
MSN,
13
May, 2015
Drought
in Australia; an end to
drought in Brazil; poor crops across Asia; record global
temperatures. If you start hearing about these in the next year,
remember this news from the week:
El
Niño is back.
That's
the word from scientists who have been watching the
tropical Pacific. Surface temperatures there are going up, winds
are shifting and that could mean big weather-related changes
around the world over the next year or so.
El
Niño is
part of a climate cycle in the tropical Pacific known as the El Niño
Southern Oscillation; it flips back and forth every few years
between the cool La Niña and the warm El Niño phases. In the
El Niño phase, ocean surface temperatures rise, easterly trade winds
along the equator slow or even reverse and the planet in general
tends to warm up.
Scientists
expected El Niño last year, but it was a no-show. But this
year, American
researchers reported in March that
a weak El Niño had finally set
in. Now Japanese andAustralian scientists
say it's definitely here, and likely to be much bigger than the
American predictions — with global
implications.
©
Credit: NOAA Maps of typical jet
stream locations and patterns during La Niña (left) and El Niño
(right) winters. Patterns are similar in spring, but are often
weaker. Based on original graphics from NOAA’s Climate Prediction
Center.
In
parts of Brazil, it could mean a lot more rain — which could be a
good thing, with the capital São Paulo and other parts of the
country in
the midst of a wrenching drought. In
Australia, the effect may well be the opposite: drier and hotter
weather in many areas, possibly exacerbating existing water
shortages.
That
heating and drying out could stretch from Australia all the way
around to eastern Africa and southern Asia, possibly cutting into
harvests of key crops like rice, soybeans, corn and palm
oil from India to China to Indonesia.
©
NASA/Jet Propulsion Laboratory
n
the United States, El Niño often brings rain to California and the
South, raising hopes that a return this year would bring drought
relief to the parched West Coast. That seemed unlikely when
scientists identified the weak El Niño in March, figuring it
would be too
small to have much of an impact.
But the prospects for substantial rain could be improved with
the revised forecast.
Meanwhile, the
global forecast is for higher overall temperatures, quite possibly
even a record.
Until
last year, the hottest year on record was 1998, which saw a big El
Niño. After that, the next warmest was 2010, another El Niño
year. Last
year broke both of those records by
a hair, which was a bit of a surprise — and a concern to
many, because it wasn't an
El Niño year.
But
with the overall temperature trend sharply up — the
10 hottest years on record have all come since 1998 —
scientists are anticipating that the warmth contributed by El Niño
may well bring another new global record, and perhaps put to rest the
contention by climate change deniers that global temperatures have
plateaued.
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