A climate influencing phenomenon that occasionally makes its way into the news is that of El Niño and La Niña, more correctly qualified with “Southern Oscillation” and abbreviated to ENSO. The warming of the Pacific near South America, heralding the start of an El Niño event is usually noticeable around Christmas, and the name, being Castellano for “the little boy”, is a reference to the Christ child.
For air temperatures through the 1950s, 60s, and 70s, the El Niño events generally coincided with positive anomalies – in other words, higher global temperatures than the established norm. La Niña events would, on the other hand, herald negative temperature anomalies. This, though, as can be seen from the chart, changed around 35 years ago.
While the 1983, 1995 and 1998 El Niño events coincided with significant upward movements in positive anomalies, successive La Niña events have been less effective in drawing those increases back. For that reason, the next two or three El Niño events may prove not merely interesting to scientists, but the bringers of a further step change in global temperatures – a change yet further upwards.
And that upward change would be fuelled by the oceans: the recent rise in global temperatures has not been a straight line phenomenon – though the trend is only going one way – but has periods of apparent hiatus, where there is no discernable upward movement for a few years. In the meanwhile, the oceans are absorbing heat, and it is ocean currents that drive El Niño.
So while the denial lobby tries to infer that taking the period from 1997 to 2011 in isolation can be used to support their latest assertion – that warming has stopped, and that it might, just might, all start to go into reverse – the oceans are gradually storing up heat, ready to kick-start the next phase of temperature rise. That is why we should beware the coming of the Christ child.