SUMMARY
New analysis of oceanic patterns offers scientists a new understanding of the causes of the droughts that spurred Ethiopia’s deadly famine of the 1980s
A look back at famine
Everyone older than 35 remembers the tragic famine that ravaged Ethiopia and neighbouring Eritrea between 1983 and 1985 – if not because of the footage of starving children on television then because of the Live Aid concerts organised by Bob Geldof.
In northernEthiopiaalone – the hardest stricken region – more then 400,000 people died from the effects of the famine, mainly because of starvation and disease, but also due to violence inflicted by the oppressive Ethiopian army. According the United Nations, more than one million people died during the three-year famine.
One of the major causes of the disaster was a lingering period of drought that struckEastern Africain the beginning of the 1980s. In Ethiopia, the economy relies heavily on agriculture and the export of agricultural products.
The first signals were already there in 1981, when a less-serious drought wiped out harvests. ButEthiopia’s food reserves were then still large enough to handle what was hoped to be an isolated incident. In the following years, however, the usual spring rains again stayed away, and diseases destroyed crops on a massive scale in the Sidamo region, Ethiopia’ breadbasket.
By the summer of 1984, tens of thousands were dying of starvation and related diseases. Aid agencies said six million people were at risk. Food aid from the West came much too late because Western countries were reluctant to support the Marxist government of Ethiopia, and the famine became the worst in the history of modern Africa.
Thirty years later, it is clear political factors were largely at fault: aside from the West dragging its feet, the Ethiopian government preferred spending the country’s already narrow budget on its army instead of on its starving population.
But what caused the droughts in the first place? Flemish scientists, together with Ethiopian colleagues, have now solved the puzzle. A complex interplay between three oceanic patterns from three different oceans is to blame, they have announced.
Science reveals underlying cause
That oceans have an important impact on global climate is well-known. Lesser known is that climate variability – or the occurrence of local extremes – can be caused by anomalies in oceanic patterns tens of thousands of kilometres away. For example, the effects of El Niño, a band of warm water temperatures that periodically develops off the South American coast around Christmas, are felt globally.
Ethiopian meteorologists have known for many years that their weather is influenced by El Niño. However, a Flemish researcher fromGhentUniversity(UGent) has recently discovered other contributing factors apart from this one powerful “oceanic driver”.
Sil Lanckriet, a UGent meteorologist and PhD student, has pinpointed two other major influences in Ethiopia’s weather system: the so-called Indian Ocean dipole and the monsoons in the south-western part of the Atlantic Ocean.
By doing so, he was able to increase the accuracy of the country’s rainfall model dramatically. The results from the model now fit precisely with the data of the recorded rainfall (or the absence of) during previous decades inEthiopia. In other words, Lanckriet has identified the true cause of the lingering drought that caused the famine inEthiopiaandEritrea.
Description, not prediction
Lanckriet made use of a 15-year-old modelling technique called EOT. “It’s a method used to find large-scale atmospheric patterns,” he says. “In Earth observation data, we use this technique to examine each pixel of millions that make up satellite images and to identify the ones that have the greatest influence on the global picture. Using EOT, we found relevant patterns not only in the Pacific [due to El Niño], but also in the Atlantic and the Indian Oceans.”
According to Lanckriet, all three oceanic patterns were needed to cause the severe droughts that resulted in the famine of the 1980s. “The interplay between them altered the monsoon circulation as well as the air flow in the lower atmosphere in the tropics.”
So is this phenomenon likely to recur? Lanckriet thinks so. “Yes, it is, though we really need all three oceanic patterns to be present at the same time to cause a drought as severe as the one we saw inEthiopia. But predicting future droughts with our currently model is still difficult. It is a diagnostic model and not a real prediction model. However, we hope to construct a drought prediction model for the Northern Horn of Africa soon.”
photo courtesy Wikimedia
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