Can We Terraform the Sahara to Stop Climate Change?
Why Hacker News recommends it
Recommended in tree-planting and carbon removal threads as a sourced explanation of why greening deserts is not a simple climate fix.
What it is
Real Engineering examines whether greening the Sahara could draw down carbon and slow climate change. It concludes that the effort would be enormously costly and that changes in albedo and other effects undercut the climate benefit.
Recommended by 3 HN commenters across 2 different months, 2018 to 2021.
What Hacker News said
Recommends cpeterso · 2019-04 · on “Restoring natural forests is the best way to remove atmospheric carbon”
This video ("Can We Terraform the Sahara to Stop Climate Change?") examines how we might do just that. The conclusion is that it's technically possible (like many things), but the cost far outweighs the benefit. It also introduces new climate risks. [this video]
Recommends Latty · 2019-04 · on “Planting 1.2T Trees Could Cancel Out a Decade of CO2 Emissions”
I recently saw a video about doing this - apparently the desert is actually a really bad option if we want to combat climate change - the core problem is that the desert currently reflects a lot of light from the sun. If we cover it with forest or whatever, then suddenly we adjust the albedo of the earth and absorb more heat, negating some of the impact. Combined with the energy need to pump (and desalinate for trees - your suggestion of kelp would presumably help there) water, etc... make it not really work. Source: [this video] I recommend watching the video - it explains it better and goes into detail - it cites its own sources.
Recommends jarenmf · 2021-07 · on “Simple, solar-powered water desalination (2020)”
Greening deserts is not a good solution for climate change. In fact it might worsen climate change due to albedo changes. A nice video about this: [this video]
Cites dereke · 2018-10 · on “Carbon Removal Technologies”
I've been watching waay too many youtube videos about reforestation, agriculture and land management recently and I think I've learned a little from it (links at the end). We no longer have the number of massive herds of animals that used to roam the plains/savannahs grazing, pooing and to a lesser extent escaping from predators. This has meant that the grasslands are no longer trampled on and "fertilised". This has caused the grasses to die back, the soil to degrade, to not hold water and to turn to desert. (see the sahara, the outback, parts of china and the usa). Subsequently we've tried to be really careful with the land and not over graze it etc. which tends to have the opposite effect