# What are some of the global impacts of technologically converting desert biomes into grasslands? [closed]

As per the Koppen climate model, for the purposes of this question deserts are dry, non-polar climates.

https://en.wikipedia.org/wiki/Desert_climate

At a hypothetical time in near future, the human race has transformed all the deserts in the world into grasslands. What are the pros and cons of desert extinction in this world?

Please include references to historical events or earth science. Thank you.

## closed as too broad by Renan, StephenG, Aify, Brythan, L.Dutch♦Jun 6 '18 at 3:27

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• This is far too complex a subject. For example, sand from the Saharas gets blown into the high atmosphere and falls onto the south american rain forest, bringing nutrients. Making the Saharas a jungle might turn the rain forests into a new desert in turn. – Renan Jun 6 '18 at 0:26
• All deserts or just the hot ones, cause the polar bears aren't gonna lime their ice made into grass lands, and where is all that water going – Amoeba Jun 6 '18 at 0:43
• Pros relative to what/who? Cons relative to what/who? Aside from being too broad, this question is very POB right now. – Aify Jun 6 '18 at 1:02

Welp, right off the bat it would cause the extinction of a large number of desert dwelling species, so that's generally frowned upon. But if that's of nominal importance to the people of the world of the tomorrow, far it be for me to pass judgment.

Other than that, deserts don't become deserts through random happenstance. To prevent the imported sod (or whatever was used) from turning back into arid sand, massive changes to global climate would have to be taken. I can't imagine the result changes of this scale would cause, but it would probably cause as many extinctions as the ice age. Again, not my place to judge.

The pro would be a notably easier time traveling though places like the Sahara, but, unless humans forgot how to make airplanes, it wouldn't benefit anyone except the people who live within deserts (who livelihoods and culture just got wiped out. Hope you like being Utah, state that used to be Arizona).

Your future people would get more farmland, probably, but it would have been a lot easier to grow those crops indoors via hydroponics.

As a whole, I wouldn't recommend the world council allocating funds to undergo this project.

• people would get more farmland I believe many current deserts became so due to farming taking over woods and forests. – Renan Jun 6 '18 at 17:19

Just to let you know, I'm much better at cons with a topic like this.

## Let's assume they do this without engineering our orbit to prevent Milankovitch cycles

The immediate question is where the water to do this is coming from, and the less obvious follow up is to ask what they did with the salt.

To paraphrase the video (it's short) water for irrigation naturally contains more salt than rain. The longer an area uses irrigation, the more salt builds up in the soil, so trying to create grasslands through irrigation will literally salt the earth. This in turn will prevent most plants from growing.

To be fair, the video points out that this problem is mostly associated with food crops like corn and wheat, due to their shallow root structures. And while it's true that some native grassland plants can have root systems just over 4.5 meters (15 feet) deep, it probably still won't be deep enough to reach the water table in an arid desert.

So without removing the salt, the con is that they would be salting the land, making any benefit extremely short-term for all of that effort.

But, what if they did remove the excess salt before using it for irrigation? We do have desalination plants already.

Well, don't believe anyone who tells you brine from desalination plants can safely be returned to the ocean.

https://www.scientificamerican.com/article/desalination-breakthrough-saving-the-sea-from-salt/

So the other con is going to be that you're going to have a lot of toxically salty brine on your hands, and even if you turn it into baking soda as in that article, you're still going to have massive amounts of calcium chloride - which is an irritant and desiccant - left over.

https://en.wikipedia.org/wiki/Calcium_chloride