If the Sahara was a forest lots of years ago ;Why cant they clear the sand and mine coal???

Answer 1

The climate of the Sahara has undergone enormous variation between wet and dry over the last few hundred thousand years. During the last ice age, the Sahara was bigger than it is today, extending south beyond its current boundaries. The end of the ice age brought better times to the Sahara, from about 8000 BC to 6000 BC, perhaps due to low pressure areas over the collapsing ice sheets to the north. Once the ice sheets were gone, the northern part of the Sahara dried out. However, not long after the end of the ice sheets, the monsoon which currently brings rain to the Sahara came further north and counteracted the drying trend in the southern Sahara. The monsoon in Africa (and elsewhere) is due to heating during the summer. Air over land becomes warmer and rises, pulling in cool wet air from the ocean. This causes rain. Paradoxically, the Sahara was wetter when it received more solar insolation in the summer. In turn, changes in solar insolation are caused by changes in the Earth's orbital parameters.

By around 2500 BC, the monsoon retreated south to approximately where it is today,[8] leading to the desertification of the Sahara. The Sahara is currently as dry as it was about 13,000 years ago.[9] These conditions are responsible for what has been called the Sahara Pump Theory.

Answer 2

There's plenty of evidence that large parts of Saharan Africa were once covered by trees before being covered by encroaching sand dunes. Other parts of Africa that were recently desert are now vegetated (see the "fossilized" Kalhari Desert, Namibia). This is all evidence of significant climatic change within the very recent geological past, say, within the last 100,000 years, and is probably connected with the last ice age.

However, it takes many million years for coal to form. You need a rather special combination of geological factors for coal formation. These include a warm, wet climate, a gently subsiding sedimentary basin, and periodic marine inundation allowing the accumulation and preservation of thick peat deposits in an anoxic (oxygen-starved) environment. You also need subsequent burial under at least several kms of overlying sediment (the precise amount varying according to the geothermal gradient or heat flow from the Earth) to facilitate the change from layers of watery peat into seams of hard coal). Now you may have some big sand dunes in the Sahara, but nowhere near several kms thick!

So the bottom line is - sorry - no coal under the sand dunes of the Sahara.

(On a practical note, can you imagine how difficult it would be to shift all that sand without the wind blowing it back again?!?)

Answer 3

O.K. Coal Formation 101. Coal is the end product of lacustrine (lake) and coastal marine plant growth. In other words, lots of water is needed. As conditions reached anoxic (the absence of oxygen) conditions, a reducing environment became condusive to the formation of peat. With the proper pressure and temperature relationships coal if formed. The bottom line is that the Sahara may or may not have had these conditions. If these conditions occurred then it becomes a complicated matter of locating the coal pockets; not an easy task given all that sand, hot weather and lack of water. In addition, most coal contains sulfur, thus making it an undesirable fossil fuel. Until the price of coal skyrockets, any unproven reserves of coal in the Sahara Desert will remain buried under all that sand.

Answer 4

Just because the Sahara was a forest for some period of time just doesn't make for it having coal deposits. Moreover, there is plenty of coal in the US that has processing equipment in place, and the cost of clearing the sand (where do you put it?) would be tremendously high.

Answer 5

I like this one - the Sahara as with all of the deserts across the globe need to be land filled and flooded with sea water! The rising sun will allow for waters to recede and the sea levels can only go lower given time.
As for the rainforest being built there - I think modern people will more likely be in to build a bathing area for all walks of life.
Mixed with cement sands can cure the whole of Africa and could house everyone as it does the rest of the world. No more huts and cattle going belly-up!
As for mining - the only pure thing they will get out is salt! It's too darn hot for anything else - time for a dip and cool off!

Answer 6

There probably isn't any coal down there. The set of conditions required to make coal may have never existed there and only other types of fossils remain to show that a forest was ever there. I believe that peat bogs and swamps are more likely to produce coal than forests.

Answer 7

Have you ever tried digging in sand to make a sand castle? Or even walking in sand? How it just keeps pouring back, and pulling down, no matter how much you dig?

Answer 8

it's always been desert - no evidence to the contrary, just speculation