The notion of a ‘wet Sahara’ in the recent past is controversial among secular researchers since they struggle to adduce a mechanism to explain it. However, much evidence exists for it and has recently been bolstered through the discovery of ancient shorelines. And unlike the conditions proposed by secular researchers, the conditions produced by a post-Flood Ice Age in the biblical perspective provide mechanisms for explaining the existence of a ‘wet Sahara’.

Paleolake Chad covered an area of 340,000 km. much larger than the current Lake Chad

The Ice Age solution

The biblical rapid Ice Age model can explain the existence of the large and small lakes in the Sahara and the population of animals and people by a northward displacement of the Inter Tropical Convergence Zone (ITCZ). In the same way as were the lakes in the southwestern U.S., and other lakes generally around the 30th parallel of the Northern Hemisphere, the Saharan lakes were first filled during Flood runoff. Residual floodwater would have been left in enclosed basins. Evidence for this could be the marine foraminifera fossils found in the Sahara Desert. Then much more rain in the Sahara during the Ice Age would have either maintained the lakes or filled them up to overflowing, resulting in rivers and streams. Dried-up rivers and streams with amphibian fossils are found below the sand. Such a wet environment was caused by much greater evaporation from the Ice Age warm ocean and a different general circulation from that evident today. But the wet Sahara continued after the Ice Age into the mid-Holocene, likely because the ITCZ was displaced much farther north.

There was only ever one ice age, it followed the worldwide flood and lasted about 700 years.

The Ice Age lasted longer in the Southern Hemisphere (SH) than the Northern Hemisphere (NH). Glacial maximum was reached about 500 years after the Flood with deglaciation taking another 200 years, lasting a total of 700 years. However, the SH would not reach glacial maximum until perhaps 300 years later, because of the time needed for the build-up of the Antarctic Ice Sheet. The atmosphere and oceans of the two hemispheres have only a minimal exchange of water and air between them, so each generally acts independently. And because the SH has much more ocean than the NH, it would take longer for the Southern Hemisphere oceans to cool (cooling is 75% by evaporation and 25% by cool airflow off the continents).

How does this explain the green Sahara in the African Humid Period? It is known that today, the ITCZ migrates seasonally away from the winter hemisphere, within a range of about 10° latitude.⁸ Therefore, after the Ice Age ended in the Northern Hemisphere, the Ice Age in the Southern Hemisphere would have pushed the ITCZ even farther north than it shifts today as the seasons change. The SH Ice Age could easily push the ITCZ 600 km (375 mi) north into the Sahara Desert and cause the green Sahara to persist for centuries after the ice sheets had disappeared from northern regions.

Both creation and secular geologists agree that the earth’s deserts and semi-arid areas were once well-watered. Creation scientists largely attribute this to the warmer ocean water just after the Flood, warmed by the enormous volcanic eruptions that took place during the Flood. Warmer oceans generated huge amounts of evaporation, which caused the great ice sheets to build up rapidly over many parts of the world, leading to the Ice Age. At the same time, the extra water vapour in the atmosphere caused high rainfall at lower latitudes where it was not cold enough to form snow and ice. Thus, the post-Flood Ice Age explains why the earth’s deserts and semi-arid areas were once well-watered.

This high-rainfall condition would have lasted for several centuries until the sea had cooled off and reached equilibrium with the atmosphere, as it is today. In the runoff stage in the last part of the Flood, many lakes would have formed from the ponding of water in enclosed basins on an already waterlogged Earth. After the Flood during the Ice Age, high rainfall would have caused these lakes to grow and be sustained, along with a network of rivers and streams.

Taken from the article “Ice Age megalakes did exist in the Sahara” by Micheal Oard in the Journal of Creation/2023, volume 37, in the section Perspectives