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How the Great Green Wall is holding back the Sahara desert

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Re: How the Great Green Wall is holding back the Sahara desert

#21

Post by wara23arish »

anon291 wrote: post #4

It seems crazy to me that after we've had so many unintended consequences preventing earth's natural processes using technology, the same crowd is now celebrating using technology to prevent yet another of earth's natural processes. Regardless of your position on the Sahara desert, it's been growing since Roman times. Personally, I'm in favor of the use of technology to affect the planet, but it seems to me that the…

Everyone is okay with building walls to hold off rising sea waters. Why is this any different?

Re: How the Great Green Wall is holding back the Sahara desert

#22

Post by droningparrot »

deegles wrote: post #16

Reminds me of the proposal to flood the Qattara sea: https://news.ycombinator.com/item?id=35957814

I think the big difference here is that the Qattara Sea would be a major engineering project involving specialized skills and machinery.

The Great Green Wall is more open in that anyone can contribute to its construction. All you need is a shovel and some seeds.

Re: How the Great Green Wall is holding back the Sahara desert

#23

Post by dev1ycan »

VintageCool wrote: post #20
zafka wrote: post #9

Earlier quoted context omitted.

Never is a pretty long time. One of my favorite authors: Doris Lessing, wrote a book called: "Mara and Dan" which has a very interesting take on climate change. I would recommend all of her books to anyone who wants to stretch their perception of our world.

Okay, sure, if you look at geologic timescales then eventually Africa will move and the region of northern Africa will cease to be desert. Within a human timescale, I think "never" is an acceptable term. Atmospheric circulation means that the latitude of the Sahara is blasted with cool dry air from the upper atmosphere. Humans planting trees might slow the spread of the desert, but will not vanquish it. To disrupt th…

"For several hundred thousand years, the Sahara has alternated between desert and savanna grassland in a 20,000-year cycle caused by the precession of Earth's axis (about 26,000 years) as it rotates around the Sun, which changes the location of the North African monsoon."

https://en.wikipedia.org/wiki/Sahara#:~:text=For%20several%2....

Re: How the Great Green Wall is holding back the Sahara desert

#24

Post by blagie »

droningparrot wrote: post #22
deegles wrote: post #16

Reminds me of the proposal to flood the Qattara sea: https://news.ycombinator.com/item?id=35957814

I think the big difference here is that the Qattara Sea would be a major engineering project involving specialized skills and machinery. The Great Green Wall is more open in that anyone can contribute to its construction. All you need is a shovel and some seeds.

Citation required and requested.

I can plant a hundred trees, keep them up for a year, and find a hundred tree stumps in two. I genuinely would like to know where on the spectrum this is:

- This is a fools' errand

- This requires constant upkeep and detailed construction

- This requires mild upkeep

- This is self-sustaining, can be done with a shovel + seeds, and once started, is self-sustaining, with the forest turning the Sahara green

Re: How the Great Green Wall is holding back the Sahara desert

#25

Post by bigbillheck »

bcrosby95 wrote: post #6
debacle wrote: post #5

Earlier quoted context omitted.

I respect the right of Africa to try and reforest, but logically the most likely outcome is that the Amazon will start to die from the lack of the 30 million tons of dust and sand that fall on the Amazon each year from the Sahara. Should Africa's desert be preserved to feed the Amazon? That's a question humanity seems ill equipped to answer.

The Sahara desert is 3.5 million square miles. That will never be re-forested.

Not with that attitude.

Re: How the Great Green Wall is holding back the Sahara desert

#26

Post by thinkingtoilet »

My question is are there downstream effects? The planting techniques are fascinating but the water that they are capturing surely was going some where, right? However little the stream may be, how do they do this without messing up people who are downstream?

Re: How the Great Green Wall is holding back the Sahara desert

#27

Post by pwthornton »

thinkingtoilet wrote: post #26

My question is are there downstream effects? The planting techniques are fascinating but the water that they are capturing surely was going some where, right? However little the stream may be, how do they do this without messing up people who are downstream?

I have to imagine a lot of it evaporated because it wasn't being captured, and then others became runoff that may have gone out to sea if it had been raining too hard.

Re: How the Great Green Wall is holding back the Sahara desert

#28

Post by micromacrofoot »

thinkingtoilet wrote: post #26

My question is are there downstream effects? The planting techniques are fascinating but the water that they are capturing surely was going some where, right? However little the stream may be, how do they do this without messing up people who are downstream?

hard to imagine a downstream effect that's worse than becoming part of the sahara

Re: How the Great Green Wall is holding back the Sahara desert

#29

Post by evandale »

VintageCool wrote: post #20
zafka wrote: post #9

Earlier quoted context omitted.

Never is a pretty long time. One of my favorite authors: Doris Lessing, wrote a book called: "Mara and Dan" which has a very interesting take on climate change. I would recommend all of her books to anyone who wants to stretch their perception of our world.

Okay, sure, if you look at geologic timescales then eventually Africa will move and the region of northern Africa will cease to be desert. Within a human timescale, I think "never" is an acceptable term. Atmospheric circulation means that the latitude of the Sahara is blasted with cool dry air from the upper atmosphere. Humans planting trees might slow the spread of the desert, but will not vanquish it. To disrupt th…

Why are we working in human timescales? It's like saying the sun will never burn out because humans won't be around to see it happen.

To me, that's a pretty bold and naive claim.

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