Would it be possible to turn Sahara desert green again? According to one scientist, yes. Although it wouldn't be a simple, nor small task, on the drawing board it's not just possible to stop the expansion of Sahara desert, but it might be possible actually to reverse its course.

Eugenia Kalnay, a prominent scientist at the University of Maryland, has been working on coming up with ways to do that for a decade now, and she thinks she has finally found a way. Not an easy way, not a fast way, for many of us not even an imaginable way, but definitely a way.

What leads to desertification?

If there's drought, the green vegetation starts to disappear. Once most of it is gone, the remaining lighter colored dirt reflects more of the sun and this cools the land surface. Cooler land surface means that "there's less heat driving air upward into higher and cooler levels of the atmosphere - the process that normally produces precipitation. So there's less rain, killing even more vegetation." (source)

The solution

What Kalnay thought of was that if it works in one direction, you could theoretically be able to make it go in the opposite way as well. She said, "It occurred to me that the same [cycle] would go in the opposite way, so it would increase precipitation, and vegetation, and then more precipitation."

And what she came up with was solar panels. The dark non-reflective panels could heat up the surface and revive rain-bringing currents. Based on her simulation, if we'd cover 20 percent of Sahara with solar panels and wind turbines, the rainfall in the area would increase and it would also bring back vegetation.

After finding the solution, she said that "We were so happy because it seems like a major solution for some of the problems that we have."

The challenge

It all sounds easy enough, right? Well, it does. However, the solar farm that she imagines is around 20% of Sahara, or in other words the size of United States, consisting of a few billion solar panels and windmills. On the other hand, if it would be done, it would generate as much electricity as our entire planet needs right now, plus three times more.

While the size of it all sounds unimaginable, the crazy thing is that the technology for that is already available, so in theory it could be done right now. Turn much of Sahara green plus produce clean energy for the entire world.