Wyrd - OE: that which has become; fate-shaping; destiny-unfolding

Friday, 9 May 2014

Is the 'little fella' about to bring big trouble in his wake?

Peruvian fishermen fear him, hurricane-battered Pacific islanders hope for him, and parched Californians are right now praying for him. El Niño - the 'little boy' or Christ-child - is gathering himself for a reappearance later this year, ready to wreak havoc with weather across the globe. Today the US's Climate Prediction Center pegged the chances of an El Niño event swarming across the Pacific at 65% for the summer - and 80% for the autumn.

With the hot-tempered little lad come changes across the globe - from heightened fire-risk in Australia and winter cloudbursts in California, to fisheries failures in the east Pacific. Naturally enough, headline writers are rolling out the gloom-and-doom headlines. Time to mark up a notch to the growing chorus of 'climate chaos', then? 

Not so fast.

After all, El Niño, for all its global meteorological drama, is part of a natural rhythm of wind and ocean movements, which have persisted for millennia. 

The sea-temperatures across the middle of the world's largest ocean have beat out an erratic pulse between hot (El Niño) and cool (La Niña) since at least the start of the last ice-age. There is certainly drama in El Niño, and the wave of consequences it pushes across the rest of the world. But it is a drama that's rather long in the tooth.

There is, however, something else of far-reaching significance in the story of this year's potential El Niño. When it comes to measuring global temperatures, it turns out that El Niño years are hot years. During La Niña and 'neutral' years, the Pacific ocean tends to store vast amounts of heat beneath its surface, especially in the western parts of the ocean. When El Niño arrives, and stamps his little foot, much of that heat is released back to atmosphere.

On average, El Niño years are 0.1 to 0.2 C warmer, across the globe,  compared to years without an El Niño or La Niña. In effect, El Niño's are periods when global warming gets a little kick. Given that the last 15 years or so have seen global surface air temperatures held back on a leash, compared to decades before, that additional energy could come as something of a shock.

It doesn't end there. 

That kick of extra energy might be considerably more forceful than normal - not all El Niños are created equal. Some are relatively tame, like 2010's. Some are monsters, like the one that struck in 1998, the so-called 'super El Niños'. And 2014 may be one to earn the 'super' suffix. Already some meteorologists, looking at the vast pool of anomalously warm waters heading towards the surface, see signs of this year's El Niño being a big one. The Kelvin wave that kick-started predictions of an El Niño has one of the largest temperature anomalies on record.

If it does turn out to be super-sized, we could see global temperatures soar to new heights over the next year or so.  With many of the planet's critical systems near to tipping points of irreversible change - from the Arctic sea-ice, to the Amazon rain-forests, to patterns of ocean circulation - that's not good news. Let's hope that the cries of this particular little infant are quickly soothed.

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