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West Africa Struggles to Fill a Climate Knowledge Gap

The Sahel region has seen drought and downpours intensify but scientists still cannot predict the long-term trend
Koungeul



Flickr/Senegal - Agosto de 2009

DAKAR, Senegal – Just two seasons exist here: the rainy and the dry. At the best of times, the temperamental rains come for three or four months and turn dusty plains into green pastures, forests and fields.

But in the late 1960s, the rains came later and ended earlier. A drought started. Crops failed across the region; freshwater rivers turned to saltwater.

In the Sahel, a semi-arid belt across West Africa south of the Sahara Desert, at least 100,000 people perished and millions of cattle died for want of pasture. That was just in the beginning. The drought persisted – for five years, then 10, then 20.

The severity provoked a humanitarian catastrophe. It was the crisis of a generation, yet scientists did not understand why it was happening.

In the 1980s, with the drought still ongoing, Gregory Jenkins was studying atmospheric science as a graduate student at the University of Michigan. After finishing his doctorate, he moved to Boulder, Colo., for a fellowship with the National Center for Atmospheric Research. He focused on West Africa – in part because of the prolonged drought's ravaging impact. But he also saw a chance to develop a niche in a region where few other climate scientists were active.

"These changes were big. They caused hardship on tens of millions of people. Not for one year, but for decades. And we didn't see anything like that around the globe," said Jenkins.

Today Jenkins is an associate professor at Howard University and a climate modeler, a profession not particularly known for its field opportunities. But early on Jenkins realized that the global climate models are too coarse to tell much about what's going to happen in the Sahelian zone.

He had to get to Senegal.

***

The drought ended in the 1990s. Life in the Sahel hasn't been the same since. Pastoralists couldn't afford to rebuild their herds. Farmers abandoned their fields. Rural areas emptied, with once-thriving regional centers transformed into ghost towns that have never been able to bounce back. The ensuing urban explosion had its own consequences, too – in poverty and crime and even the pressure to leave the continent and go abroad, with papers or without.

Scientists now believe that the Sahelian drought was an indication of climate change. They expect climate change to do a number on this ecosystem, causing droughts and floods, disasters upon disasters. Prevention might not be possible, but if the world knows what's coming, local governments could at least prepare.

In 1993 Jenkins packed some instruments and headed to Dakar. In the two decades since, he has returned every year, traveling the countryside, visiting with friends, installing rain gauges, stopping for a bowl of ceebujen, the national dish of fish and rice. He'll sit with Senegalese colleagues on their ateliers and help their students analyze data. Sometimes he brings his students from Howard University. It's important, he says, to expose young Americans to important science and societal issues abroad.

Senegal has been a good base, too, with consistent political stability over the last 20 years. Every country that it shares a land border with has had a coup d'etat or two or even three since then.

In Africa, weather systems develop from east to west, but continuous data are rare. Security problems and war plague parts of the region. Funds are scarce. "We have no data from Sudan, not much from Chad, and we know the weather systems are developing and going past those areas. And when bad things happen in Mali, we know we lose observations," he said. Satellite data can help, he added, but it is sometimes too coarse to be meaningful.

This gap hampers scientists' ability to understand what the future holds for this part of the world. Scientists don't know if West Africa will be wetter or drier. And that has huge policy and humanitarian implications.

"The tools that we use to tell us something about climate change cannot give us an answer about how to prepare for climate change for most of the continent," Jenkins said.

***

Oumar Sakho grows corn and sorghum during the rainy season at his farm in Sangalkam, about an hour outside of capital city Dakar. He's also the president of a local rural development organization.

In 2011 drought again swept the country, and almost 90 percent of local farmers lost their corn crop. Only the farmers who planted in low-lying areas or basins escaped the drought. Sakho lost just about everything that year. But in 2012, the opposite was true: abundant rains meant that the farmers who planted in basins were flooded out, but other farmers had a bumper crop.

Since 1990 rainfall has returned to the Sahel at levels slightly below the 1900 to 1993 average, according to Global Historical Climatology Network data. But year-to-year variability has been high.

"The problem is that before the rainy season, you have to make a choice," said Sakho. "If you make the wrong choice, you risk losing everything."

Down the road from Sakho sits the model farm of the National Federation of Market Gardeners, where workers on a typical February morning watered cucumbers and cabbage plants with hoses. During the long dry season farmers here depend on irrigation to water their vegetable crops, growing lettuce and tomatoes, green beans and onions, mangos and melons for urban markets all over the country and for export to Europe. Mango revenues alone bring millions of dollars into the Senegalese economy, and Sidy Gueye, the coordinator, said that horticulture here is big business for small farmers.

The water table is normally high, and ground water is easy to come by. But irrigation also depends on the rainy season, Gueye cautioned. "If there's not a good rainfall, the water table suffers."

***

For now, the future of climate research in West Africa  – an area that spans 16 countries – rests partly in about three narrow rooms on the second floor of a run-down building on the edge of the Cheikh Anta Diop University in Dakar.

Science posters line a narrow hallway, crowding out a plaque laboratory director Amadou Gaye received from the Nobel Prize committee for his work on the 2007 IPCC report. On the roof, a cluster of aging instruments measures lightning, dust, solar radiation and wind.

The instruments sometimes break. No one knows how to fix them.

Gaye said that governments in West Africa are eager to get started adapting to climate change, but they don't have any idea what that change might be. "They don't think we need to develop hard science in Africa, only social science," he said.

But many of West Africa's social problems in the future might just come from the lack of investment in this particular hard science, he warns.

After all, had the world known in the 1970s that drought would continue for 20 more years, maybe local governments would have done things differently, he mused. Maybe they would have planned for the rural exodus that swelled the urban areas so fast that the infrastructure could not keep up. Maybe they would have invested earlier in training to help people in the rural areas be more resilient.

Maybe instead of treating the drought as a temporary crisis, they would have recognized that the world they knew would never be the same again.

On the Web:

Gregory Jenkins, Howard University

Sahel precipitation data

This article originally appeared at The Daily Climate, the climate change news source published by Environmental Health Sciences, a nonprofit media company.

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