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WATER POLITICS

Courtesy of National Geographic, an article on the historic drought impacting 20 million living in Horn of Africa:

 

Hope now rests on seasonal rains over the coming weeks. Unfortunately, the forecast is not promising—and perhaps unsurprisingly, it appears climate change is largely to blame. As part of the Famine Early Warning Systems Network (FEWS NET), Chris Funk and colleagues at the University of California, Santa Barbara Climate Hazards Centre use climate models to generate maps of rainfall estimates around the world. They have found that the root of the Horn of Africa’s recent droughts can be found far to the east, in the warm (and warming) waters of the western Pacific Ocean, and in the climatic phenomenon known as La Niña.

Warmer waters, less moisture

The impacts of La Niña and its sibling El Niño—together known as the El Niño Southern Oscillation (ENSO)—are well established in the countries around the Pacific Rim. In the United States, for example, La Niña generally prompts drier winters in the South and Southwest and colder winters in the North, while El Niño induces warmer northern winters and cooler, wetter conditions in the South. But their reach extends across much of the globe, including Africa.

When the sea surface is warmer in the western Pacific—as is the case under La Niña conditions—the air over Indonesia warms, rising and traveling west as far as East Africa. There it collides with air travelling in the opposite direction from the Atlantic, and sinks. That creates hot, dry conditions that also act as a barrier to incoming moisture from the Indian Ocean. (This graphic from the U.S. National Oceanic and Atmospheric Administration illustrates the process.)

The connection has not always been so clear-cut; between 1950 and 1997, only 28 percent of La Niña events were followed by poor rains in the eastern Horn of Africa. However, Funk explains, “following the 1997-98 El Niño, temperatures in the western Pacific increased and have remained high relative to the previous half-century.”

Since then, he notes, approximately 80 percent of La Niña events are followed by a meager rainy season. And, to add insult to injury, as the western Pacific warms, La Niñas also now occur more frequently: There were 12 recorded between 1954 and 1998 and another 12 since then, including the last two years.

Unfortunately, Funk continues, there is little sign of a let-up. “Current sea surface temperature observations and forecasts continue to resemble many recent dry March-to-May rainy seasons,” he says, which suggests strongly that a fourth consecutive failed rainy season is in store.

Dire scenes in Kenya

In a blog post, WFP’s Tomson Phiri describes the scene in parts of rural Kenya. At one pastoral family’s homestead, he writes, the land was “virtually empty and silent, with no livestock in sight. On any given day, they would have had between 200 to 300 animals—camels, cattle, goats and sheep.” The drought, he writes, is “widespread, severe, and likely to grow worse.”

Dead livestock, killed by thirst and hunger, are common along roadsides. As water levels fall, so too does access to clean drinking water. With harvests as much as 70 percent below normal levels, food prices are skyrocketing; Phiri notes that “the amount of cereal that could be purchased with the sale of a goat has dropped in some cases by up to 40 percent below the five-year average in Kenya, and by over 80 percent in parts of Somalia.”

And yet, the situation could still worsen.

Prior to 1999, the countries in the eastern Horn of Africa typically experienced two rainy seasons each year—a so-called “short” season in October-December, and a long season in March-May. But approximately every five to six years the area would suffer a period of drought as one of the rainy seasons failed..

Since 1999, however, on average “poor March to May rains are coming every two to three years.” A single failed rainy season can cause hardship. Two in a row can create famine, as when 260,000 people, half of them children, died in Somalia following back-to-back droughts in 2010 and 2011. If the upcoming season were to fail, it would be the fourth in a row, plunging the region into a drought of a length not experienced since 1981 and placing as many as 20 million people at risk.

Even that does not tell the whole story. Since the October-December rain season in 2016, rains have failed six times. On three of the occasions when rains have come, they have been so heavy that they have caused flooding.

Extreme rains in October to December 2019 were the wettest in East Africa for more than 40 years and affected an estimated 3.5 million people, resulting in a reported 350 deaths and killing approximately 96,000 animals. The explosive vegetation growth prompted by the rains provided food for locusts, which erupted into the largest swarms Kenya had seen for 70 years. In February 2020, local media reported that one single swarm had reached more than 900 square miles, making it perhaps the largest on record in the country.

These massive rains may also be the result of a changing climate. Funk notes not only that warmer atmospheric temperatures allow for more water vapour and hence greater precipitation, but also that the 2019 rains coincided with an extreme Indian Ocean Dipole event, a relatively recently recognised climate pattern that has been called “ENSO’s neighbour” and the “Indian Niño.”

The phenomenon had already been associated with heavier rains in East Africa. In late 2019, Funk notes, sea surface temperatures were “incredibly warm in the western Indian Ocean, in fact the warmest ever in that area, and the winds reversed across the Indian Ocean.” The net result has been a climate change-fuelled battering of the eastern Horn of Africa, drought followed by drought followed by flooding, with barely an opportunity for the region to catch its breath.

The situation is further exacerbated by the fact that, as WFP’s Dunford says, “This is a region beset by conflict. We estimate there are 4.6 million people as refugees, and almost 11 million people that are internally displaced across the region.”