What If We Terraformed The Sahara Desert?

WHAT IF

Why don’t we transform the Sahara Desert into a lush rainforest?

Transcript

00:00 In an effort to fight climate change,

00:07 the Sahara Desert could be going green.

00:10 Literally.

00:11 Plans are being made to terraform the entire Sahara Desert,

00:15 changing it from a dry, barren landscape

00:17 to a lush green space.

00:20 If successful, the transformation could remove

00:22 7.6 billion tons of atmospheric carbon yearly.

00:27 How could we change the nature of such a vast, isolated landscape?

00:33 Could we afford the giant price tag that would come along with it?

00:36 And have we ever done anything like this before?

00:41 This is WHAT IF,

00:42 and here's what would happen if we terraformed the Sahara Desert.

00:47 The Sahara Desert is 8.6 million square kilometers in size.

00:52 It's roughly the size of America,

00:54 if you filled America with sand and took away all the trees.

00:58 Terraforming an area this massive wouldn't be easy.

01:01 In fact, it would cost about $2 trillion a year.

01:05 And unfortunately,

01:07 the price tag would just be the beginning of our obstacles.

01:11 What kind of environmental domino effect would this create?

01:16 Plants and trees are the lungs of the Earth,

01:18 and right now we could use a lot more of them.

01:21 A single hectare of trees can absorb the same amount of carbon dioxide

01:25 you would produce by driving a car for 100,000 kilometers.

01:30 If we could successfully terraform the Sahara,

01:33 it would result in millions of hectares of trees

01:35 being added to the battle against climate change.

01:39 That all sounds great,

01:40 but what are the odds we could pull this kind of transformation off?

01:44 Believe it or not, we already have,

01:46 just on a smaller scale.

01:49 China's Kabuchi Ecological Restoration Project

01:52 saw the successful greening of one-third of the Kabuchi Desert,

01:55 with 70 different plant species over a 30-year time span.

01:59 How could we scale that up for the largest hot desert on Earth?

02:03 One idea is to plant crops and trees,

02:06 and then pump desalinated water from the coast of the Sahara to irrigate them.

02:11 To prevent evaporation,

02:12 the water would be carried by underground pipes to reach the roots directly.

02:17 The ideal things to plant would be eucalyptus trees,

02:20 since they're hardy and they do well in hotter climates.

02:24 Plus, they grow quickly and could be economically beneficial for the region.

02:29 As the trees began to root and stabilize,

02:31 the soil would be replenished with needed nutrients.

02:35 Rainfall amounts would increase,

02:36 and the overall temperature of the Sahara would cool by 8 °C (10 °F).

02:42 Okay, so with time running out in our fight against climate change,

02:46 why aren't we moving faster on such a significant potential solution?

02:52 Well, first off, did we mention that it would cost $2 trillion a year?

02:56 Have fun getting international governments to pitch in on that,

03:00 especially if it's just for the greater good of humanity.

03:03 But even if we could afford it,

03:05 terraforming the Sahara Desert would come with its fair share of issues.

03:09 As the region becomes wetter as a result of millions of new trees being planted,

03:14 the risk of locust plagues increases.

03:17 Yeah, that's right, locusts.

03:19 The swarming pests best known for their biblical associations.

03:22 Wait, locusts can't be that bad, can they?

03:29 Well, a small swarm eats more than what 2,500 people can eat in a day,

03:33 so yeah, they can be that bad.

03:36 However, the biggest problem with terraforming the Sahara

03:39 would be the environmental domino effect it would create.

03:43 The Sahara sand gets carried in the air by wind power,

03:46 and is deposited in South America after crossing the Atlantic Ocean.

03:51 The dust picks up moisture during its journey,

03:54 and when it falls from the sky, rain comes along with it.

03:57 This dust and rain combo falls on the Amazon rainforest,

04:02 helping to fertilize it and providing the ecosystem the water that it needs.

04:06 No Sahara could potentially mean no more Amazon rainforest,

04:11 unless someone else steps in with a plan to avert that crisis.

04:14 So, even though a green Sahara would lower our carbon emissions,

04:19 would it be worth potentially destroying another part of the planet?

04:23 Maybe instead of terraforming one giant location,

04:26 we should spread our greening out around the world.

04:30 But that's a topic for another WHAT IF.

04:34 [music]

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