One way to change the world’s climate and its appearance would be by excavating the Sahara Reservoir.  This reservoir would take water from the Mediterranean and Atlantic, desalinize it, use it for hydroelectical energy production, and dump it into a reservoir that has a bottom at least 250 meters below sea level. 

A retaining wall around North Africa would be where the salt water would be desalinized before being allowed to flow down through hydroelectrical systems.  The water would empty into the reservoir at the end.  Employees of the reservoir system and its services would live in the wall.  They might be the displaced people that used to live in the desert.  But once the reservoir starts filling, they will need to live somewhere.

Plasma excavation equipment would remove sand and material down to 250 meters below sea level with plasma cutting heads.  There might be over 1000 of these pieces of equipment involved in the excavation work. 

Since plasma is being used, much of the sand will form glass.  This would be called Sahara glass and would be used around the world.  The glass would be excellent building material.  It could be used for the formation of more “land” for Hong Kong, Tokyo, and anywhere else that needs more land for such things as airports. 

Once the reservoir is excavated and the excavation equipment is through, it will be removed and water will be let in at a rate high enough to allow more electricity to be generated than all the hydroelectical systems in the world until the reservoir is full.  That may take weeks.  After years of excavation work, the filling of the Sahara Reservoir will be something astronauts would notice from space. 

Once the reservoir is filled, it will become the largest body of fresh water in the world.  It may contain over five times more water than the Great Lakes.  It will lower the world sea level at least a couple meters and lower the average temperature of the world at least a couple degrees.  The could be the difference between uncontrollable global warming and an inviting and stable environment.   With a large body of water instead of the world’s largest desert, the average temperature of North Africa could be lowered over 30 or 40 degrees. 

The Sahara Reservoir, if it becomes a reality, would be one of the future wonders of the world.  It will cost trillions of dollars to excavate.  But it may spare the world even more money that would be required to pay for ecological disasters.