It looks like the biggest weather event of the year is unfolding as we speak.
After waving hasta la vista to the flooding rains of La Nina from 2010- 2012, we’ve been ENSO (El Nino-Southern Oscillation) climate-neutral for almost two years. But that’s about to change, with all climate models surveyed by the Bureau of Meteorology now predicting her fearsome brother El Nino will arrive this year. Six out of the seven models forecast the arrival as early as July.
El Nino translates to "boy child" or "Christ child" in Spanish, but this kid packs a big weather punch around the world, with Australia usually copping a big blow.
The El Nino-Southern Oscillation is a climate pattern in the tropical Pacific Ocean that occurs roughly every three to eight years and causes major shifts in the weather around the globe. In its positive phase, La Nina, sea surface temperatures increase in the western tropical Pacific Ocean off the coast of north-east Australia, which is linked to increased rainfall over eastern Australia. In 2010 and 2011, La Nina delivered Australia’s wettest 24-month period on record.
The flip side of ENSO is the negative phase El Nino, where sea surface temperatures are warmer than average in the central and eastern tropical Pacific Ocean off the coast of South America. This is usually accompanied by cooler waters off Australia’s northeast coast and a subsequent decrease in moisture, which typically brings below-average rainfall, hotter conditions and a longer and more severe bushfire season to eastern Australia.
Around two-thirds of El Ninos in the last century have resulted in major droughts across a large part of our country, with eight out of the 10 warmest years on record occurring during El Nino years.
While it’s too early to predict this upcoming El Nino’s strength, current observations suggest that it could be a doozy, with sea temperatures deep below the ocean’s surface a lot
warmer than usual. The last time we saw this kind of temperature anomaly was in 1997, during the strongest El Nino ever recorded. The global effects of this event were devastating, with record flooding in Chile, an extensive smog cloud over Indonesia, marlin caught off the coast of Washington (normally found in the warm waters of Mexico) and parts of Victoria recording very little rainfall. The impacts cost over $30 billion, and the event claimed 23,000 lives.
Someone needs to call That’s Incredible!
(remember that '80s show?!), because I’ve almost reached the end without mentioning global warming. Research published by scientists from the University of New South Wales shows that while we currently experience a strong El Nino event every 20 years, this is expected to double to one in every 10 years as the planet warms. So as global temperatures rise, it looks like El Nino will arrive more often to give those heatwaves an extra boost.
It’s worth noting, however, that 2013 was Australia’s hottest year on record, despite there being no El Nino. I’ve used this analogy before, but Australia breaking those heat records in 2013 during this ENSO-neutral phase is like a racing car driver achieving a record on a wet track with poor tyres. El Nino actually tilts the odds towards extreme weather such as heatwaves, which is what makes this latest forecast so worrisome.
If we’re experiencing our hottest year on record and earlier bushfire seasons when we’re in ENSO-neutral, how severe will it get when El Nino clicks into drive?