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Green Sahara

The Great Desert Where Hippos Once Wallowed

The Sahara sets a standard for dry land. It’s the world’s largest desert. Relative humidity can drop into the low single digits. There are places where it rains only about once a century. There are people who reach the end of their lives without ever seeing water come from the sky.

Yet beneath the Sahara are vast aquifers of fresh water, enough liquid to fill a small sea. It is fossil water, a treasure laid down in prehistoric times, some of it possibly a million years old. Just 6,000 years ago, the Sahara was a much different place.

It was green. Prehistoric rock art in the Sahara shows something surprising: hippopotamuses, which need year-round water.

“We don’t have much evidence of a tropical paradise out there, but we had something perfectly liveable,” says Jennifer Smith, a geologist at Washington University in St Louis.

The green Sahara was the product of the migration of the paleo-monsoon. In the same way that ice ages come and go, so too do monsoons migrate north and south. The dynamics of earth’s motion are responsible. The tilt of the earth’s axis varies in a regular cycle — sometimes the planet is more tilted towards the sun, sometimes less so. The axis also wobbles like a spinning top. The date of the earth’s perihelion — its closest approach to the sun — varies in cycle as well.

At times when the Northern Hemisphere tilts sharply towards the sun and the planet makes its closest approach, the increased blast of sunlight during the north’s summer months can cause the African monsoon (which currently occurs between the Equator and roughly 17°N latitude) to shift to the north as it did 10,000 years ago, inundating North Africa.

Around 5,000 years ago the monsoon shifted dramatically southward again. The prehistoric inhabitants of the Sahara discovered that their relatively green surroundings were undergoing something worse than a drought (and perhaps they migrated towards the Nile Valley, where Egyptian culture began to flourish at around the same time).

“We’re learning, and only in recent years, that some climate changes in the past have been as rapid as anything underway today,” says Robert Giegengack, a University of Pennsylvania geologist.

As the land dried out and vegetation decreased, the soil lost its ability to hold water when it did rain. Fewer clouds formed from evaporation. When it rained, the water washed away and evaporated quickly. There was a kind of runaway drying effect. By 4,000 years ago the Sahara had become what it is today.

No one knows how human-driven climate change may alter the Sahara in the future. It’s something scientists can ponder while sipping bottled fossil water pumped from underground.

“It’s the best water in Egypt,” Giegengack said — clean, refreshing mineral water. If you want to drink something good, try the ancient buried treasure of the Sahara.

JOEL ACHENBACK
Staff Writer, Washington Post

The Green Sahara, A Desert In Bloom. A summary is New North African climate reconstructions reveal three Green Sahara episodes during which the present-day Sahara Desert was almost completely covered with extensive grasslands, lakes and ponds. The ancient buried treasure of the modern Sahara. Although Sahara is the largest desert with the lowest humidity where people may see rain from the sky once in a year. Yet beneath the Sahara are vast treasures of enough fresh water to fill a small sea and also hippo who needs year-round pool lived over there. But due to the shifting of the monsoon towards southern side, Sahara went something worse than drought and converted in modern Sahara around 4000 years ago. 

The ancient buried treasure of the modern Sahara
Although Sahara is the largest desert with the lowest humidity where people may see rain from the sky once in a year. Yet beneath the Sahara are vast treasures of enough fresh water to fill a small sea and also hippo who needs year-round pool lived over there. But due to the shifting of the monsoon towards southern side, Sahara went something worse than drought and converted in modern Sahara around 4000 years ago.

The Green Sahara, A Desert In Bloom. Summary: ... New North African climate reconstructions reveal three 'green Sahara' episodes during which the present-day Sahara Desert was almost completely covered with extensive grasslands, lakes and ponds over the course of the last 120.000 years.

The World's largest desert is Sahara. There rains only once in a century. 6000 years ago, Sahara was green and vast aquifers of fresh water. The dynamics of earth's motion are responsible and monsoons migrate north and south around 5000 years ago. Many geologist says that for climate change rapidly the Sahara had become what it is today. 

Climate change can occur due to natural phenomena like change in earth axis of rotation or sun come closer to earth, but it can happen by human-driven activities also. Sahara is the excellent example of climate change due to natural occurrences that happen a lot 5000 years ago when monsoon shifted dramatically to southward again, as it was earlier before 10000 years ago. Prehistoric rock art, hippopotamuses images support that some time in the back, the place has a sufficient amount of water bodies. Due to climate change surface water gets dried up but still, fresh water will be available somewhere beneath the surface. Climate change also forces the inhabitants to relocate and stay near the Nile valley where prehistoric Egyptian culture flourished. 

The article is based on climate change in Sahara. It totally revolves around the vey facts of drought circulated over the whole Sahara region and how the climate change over a peiod of time made it a drought region.

In the second and thrid para graph of the article, information about fossil water which is contained much below the earth in the sahara region, is brought to the readers notice. in the fifth and sixth paragraph of the article, the very reasons behind climate changes in the Sahara regions are listed out. Some of the importatnt factors that the Sahara, a drought spread regions aredynamics of the Earth and earth's motion around the sun and its inclination on its axis. Titling of the earth hemishpere towards the sun, forms the ideal conditions for formation of the Monsoon, and thus it causes rain in the different parts of the earth, making them inundated. Accordingly, the opposite half of the earth shpere undergoes dificeient rainfall, causing enough conditions for drought.

In last three paragraphs, outcomes of rapid climate changes, have been revealed. it unearths information about how the vegetaion and greenery of the earth are getting exhausted , water holding capacity of the earth are getting decreased due to vegetation drainage. Thus resulting in all the prevalent conditions of water drainage from the land and making the earth a drought spread.

Even possible causes of climate change, be it human driven or natural one, will cause a change in the Sahara region to how much extent , it is a matter which would be revealed in the forth coming days. Also, the fossil water found in the Egypt, beneath the earth, is the best water to drink.

The Sahara world's largest desert . There are many species or animal and plants living un that diverse conditions. Those species all have adapted themselves to the environment of the Sahara.

 There is very little evidence about the biodiversity of the Sahara but above all it is the most beautiful place. The ancients have left this beautiful treasure for us.

Beneath the Sahara are vast aquifers of fresh water, enough liquid to fill a small sea.

Just 6,000 years ago, the Sahara was a much different place.

Prehistoric rock art in the Sahara shows something surprising: hippopotamuses, which need year-round water.

The prehistoric inhabitants of the Sahara discovered that their relatively green surroundings were undergoing something worse than a drought.

It's something scientists can ponder while sipping bottled fossil water pumped from underground.

"It's the best water in Egypt," Giegengack said - clean, refreshing mineral water.

If you want to drink something good, try the ancient buried treasure of the Sahara.