A screenshot of a Facebook video showing Lake Ngami in Botswana was shared to us. It claims that climate change is not the reason as to why Lake Ngami is drying up because this has happened before.
The post has 1000 reactions, 214 comments and over 1000 shares.
“It would be incorrect to say that this is in any way related to climate change as this lake has dried out in the past. Africa is notorious for its droughts but perhaps it is a forewarning of what is to come,” the post reads.
According to Britannica, the world’s oldest published encyclopaedia, Lake Ngami is a shallow lake at the southwest corner of Okavango Swamp in northwestern Botswana. The swamp and the lake are fed by the Okavango River. In 1950 it had become a sea of grass, and during a severe drought in 1965-66 it dried up completely but after abundant rains it filled again.
Lake Ngami is located at the western part of the lower Okavango Delta in Botswana. Because it does not naturally drain, it serves as a pertinent indicator of environmental change and the climate variability of the basin.
“Seasonal ﬂooding of the Okavango Delta by discharge originating from catchments in the highlands of subtropical Angola as well as there distribution of water to the distributaries that ﬂow into the lakes Periodic Shifts in regional climate and hydrologic changes within the Okavango Delta have caused Lake Ngami to alternate between ﬁlling and drying cycles throughout its existence. However, the lake has remained mostly dry for the majority of the twentieth century,” A 2015 study titled “Processes that control water chemistry and stable isotopic composition during the refilling of Lake Ngami in semiarid northwest Botswana,” says.
Many factors contributed to the drying of Lake Ngami in the past, between 1870s and 1898, Thaoge river which was the water source for it in the northwest was blocked by papyrus and it dried. In the 80 years prior to 1983, the lake had been dry five times for two consecutive years.
Maximum levels were attained in 1898, 1899, 1904, 1925, 1926, 1968/69 and 1978/79 due to the limited inflow and drought years during the 1980s in Botswana according to the Bird Life International, an organisation conserving birds, their habitants and the global biodiversity.
Most recently, the drying of Lake Ngami is attributed to droughts and low rainfall observed in Okavango delta and Angolan Highlands where the river originates.
In an article by Africa Press,Professor Joseph Mbaiwa from the University of Botswana, Okavango Research Institute stated that climate change is the cause of dryness of Lake Ngami. He said that the recurring drought at Lake Ngami has also been observed in Okavango Delta where this lake receives water from.
“With soaring temperatures, erratic precipitation, droughts, flooding and many other natural factors, Climate change is causing the shrinking of the Okavango delta and making it to shift from north to south with some of the channels either drying up or becoming seasonal,” said Prof Mbaiwa in the article.
The claim is Misleading, climate change contributes to the drying of Lake Ngami, the lake levels were expected to fall from October to May but this has changed as extreme droughts exceed the anticipated period of dryness.
This fact-check was produced by Debunk Media Initiative with support from Code for Africa’s PesaCheck, International Fact-Checking Network and African Fact-Checking Alliance network.