ON THE shores of Lake Baringo in Kenya, a slow-motion disaster is unfolding. For the past decade, the water has been steadily rising, swallowing homes, shops, health centres, latrines, electricity supplies, farmland, tourist resorts and more. Malaria, cholera, typhoid and dysentery are increasing. Wildlife is under threat; conflict has broken out between people and animals and old grievances between neighbouring groups have resurfaced.
Since it started rising, Baringo’s surface area has more than doubled, and it isn’t alone. Right across the East African Rift valley, lake water is creeping over animal and human heads. And where East Africa leads, much of the rest of the world is following. North America’s Great Lakes have been rising too. Overall, lakes the world over have expanded to occupy an extra 46,000 square kilometres of space since 1984, roughly the area of Denmark.
When we talk about inland water bodies, , Lake Chad in central Africa and the Great Salt Lake in Utah dominate the conversation. But the global trend is actually the opposite. The cause of these increases has been debated for years, but the consensus has now settled on the real culprit: us. You have probably fretted about impending sea-level rise. Welcome to the untold story of another human-made catastrophe in the making: lake-level rise.
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East African lake-level rise
The East African Rift valley stretches from Ethiopia in the north to Mozambique in the south via Kenya, the Democratic Republic of the Congo (DRC), Uganda, Rwanda, Burundi, Zambia, Tanzania and Malawi. It is home to dozens of lakes, including : Victoria, Tanganyika, Malawi, Turkana and Albert.
The most detailed information on lake-level rise comes from Kenya, which is home to Turkana – the world’s largest permanent desert lake – a bite-sized chunk of Victoria, eight other large lakes, including Baringo, and the Turkwel Gorge dam. All are on an upward trend, with major consequences for the millions of people who live around them.
“What you see are submerged houses and reduced stability of the land around the lake,” says at the University of Nairobi, Kenya, speaking about Lake Nakuru. “Some people have had to find new places to live. Most of them, their livelihoods depend upon this lake. When it bulged outwards, they had to find other sources of livelihood. Even the gate of the [Lake Nakuru] national park, it got submerged into the water.”
Kenya’s diluvian disaster was by at Kenyatta University in Nairobi. He and his colleagues were taking measurements for another project when they inadvertently found that all four lakes in their study – Baringo, Bogoria, Naivasha and Nakuru – had risen alarmingly in the past few years. At Naivasha, the entire lake-fringe of papyrus and acacia trees was underwater. , a big tourist draw, were nowhere to be seen.
Natural climate cycles
Onywere proposed that the rising waters were the result of a natural 50-year climate cycle, as similar flooding had been recorded in Kenya in 1901 and 1963, though not well documented. However, Onywere was unaware of recordings from elsewhere in the region that drowned this 50-year-cycle hypothesis at birth. In 1981, Geoff Kite at the in Nairobi had published between October 1959 and May 1964. It then fell back slightly, but started rising again in 1978 and was still rising at the time of publication. The same was true of three other lakes: Malawi, Tanganyika and Albert.
Kite explored the reasons for the rises and concluded that no human activity could account for it. But he admitted that he couldn’t pinpoint a natural cause either.
Almost as soon as Kite published, Victoria started to recede again. By 2007, it had fallen to more than 3 metres below its 1964 peak and there were . It wasn’t. Victoria did another U-turn and, apart from a brief hiatus, its waters have been rising ever since. According to a 2021 report by the Kenyan government and the UNDP, the surface area of the lake , between 2010 and 2020.
Kenya’s 10 other major lakes are expanding too. UNDP describes the situation as a “crisis”. More than 380,000 people have been displaced and are in “dire need” of humanitarian assistance, having lost livelihoods, schools, utilities and sanitation. Several people have been killed by hippos, which now graze nearer human settlements.
“The rising lake water levels and accompanying flooding have stirred panic and anxiety among the surrounding communities where the floodwaters have left trails of destruction,” says Keriako Tobiko, cabinet secretary of the Kenyan Ministry of Environment, Climate Change & Forestry. The environment and wildlife have suffered as well.
Record-breaking water rises
Lakes in other East African countries have been rising rapidly too. , which straddles Tanzania, the DRC, Burundi and Zambia, has been on an upward trend since 2006 and hit record levels in 2021. Last year, – shared between Malawi, Mozambique and Tanzania – recorded its highest level for eight years.
The exact cause of the rising waters has long been debated. There are three possibilities, none of them mutually exclusive. One is natural climate variability, with greater rainfall the main driver. Another is natural geological activity: the rift system is tectonically dynamic and shifting plates under the lakes could conceivably change water levels. The third is human activity – principally global warming, which increases rainfall, and land-use change leading to increased water runoff into the lakes and greater sedimentation, which raises the lake bed and blocks outflow streams.
Climate change to blame
Right now, the finger points firmly at human activity, especially climate change. A 2021 study of water levels in Kenya’s lakes Baringo, Bogoria, Nakuru, Solai, Elementaita and Naivasha . Even though much of East Africa is in drought, the rift lakes region has seen increased rainfall. “Climate change is a major cause of the rising water levels,” says Onzere, the co-author of another study that largely .
Not everyone agrees, however. “The preferred scapegoat is always climate change, but I see anthropogenic land use change as the critical factor altering the hydrological cycle,” says Sean Avery, an engineer and hydrology specialist at King’s College London who is based in Kenya.
Tectonic activity also hasn’t been ruled out. A recent study of Lake Beseka in Ethiopia, which covers an area about five times its extent in 1972, found that . According to the researchers, the most plausible explanation is tectonic activity, which has torn open the lake bed, allowing groundwater to seep in, and has created new basins in which water can collect.
Nevertheless, the Kenyan government report is very clear on where it places blame. “The main reason for the rising water levels is climate change,” it says.
As usual, then, the Global South is bearing the early brunt of climate change. But Western countries largely responsible for emissions aren’t immune.
A hemisphere away, other bodies of water are also on the rise. In 2013, Lake Michigan in the US was at a record low, but then started rising rapidly and hit record highs in 2021. Nearby lakes Superior, Erie and Huron also hit record highs; the last of the five North American Great Lakes, Ontario, was well above average too. The waters have receded somewhat since then, but left behind a lot of . Some 40 million people live near the shores of the Great Lakes in the US and Canada.
At last year’s American Geophysical Union (AGU) hydrology conference in San Juan, Puerto Rico, at the US National Oceanic and Atmospheric Administration’s Great Lakes Environmental Research Lab reiterated the cause. Climate change is affecting all three of the factors that control lake levels, she said. These are precipitation over the lakes, runoff from the land and evaporation.
The lakes have risen and fallen quickly in the past, but never quite as fast. There is a historically rapid change in both directions, says at the Illinois State Geological Survey.
Great Lakes flood risk
Similar surges are forecast in the future. A model presented at another recent AGU conference in Chicago predicted that , exposing people and nature to greater damage from storm surges and flooding.
Other models are more circumspect. According to at the University of Michigan, it is still unclear how climate change will influence the three drivers of lake levels in North America. “There’s significant variability and uncertainty,” he says. Some models show large increases, others slight declines. What we can say is that water level variability in the future will be at least as great as it has been in the past, says Vandeweghe.
This story of lake-level rise is being repeated across the globe. Last year, a team led by at Southern University of Science and Technology in Shenzhen, China, from 1984 to 2019. The team came up with the 46,000-square-kilometre expansion figure mentioned earlier, but found that, if you eliminate lakes that are shrinking, the growth amounts to 167,000 square kilometres.
Around half of that involves reservoirs, but the rest is natural lakes. This spells further bad news for the climate. Lakes of all sizes are prolific sources of greenhouse gases because the decomposition of organic matter on their beds produces carbon dioxide, methane and nitrous oxide. Lakes account for an estimated .
According to the study, the extra lake area over the course of the study increased carbon emissions by 4.8 million tonnes a year, roughly the same as Kenya’s annual emissions.
Back in Kenya, fears are growing that the rising waters of Baringo will impose ecological disaster on its neighbour, Bogoria, a world heritage site and well-known tourist destination. Many of Bogoria’s famous hot springs have already been submerged in recent years and it has seen vast flocks of flamingos decimated. But worse is to come if Baringo creeps any nearer. Bogoria is a salty, alkaline lake, which is what makes it attractive to flamingos. Baringo is freshwater. If the two merge, Bogoria’s ecosystem will be ruined. The two are in the same basin and used to be 20 kilometres apart, but are now just 13 kilometres from each other.
For the foreseeable future, the lakes will carry on getting bigger. “If we continue doing things the way we are doing, it means levels are going to rise,” says Onzere. “Only if we have normal temperatures and normal rainfall amounts will the lakes come back to normal.” The world isn’t just burning, it is drowning too.
