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3 HN recommenders · recommended in 5 months, 2017–2020
37:08 · 88K views · Feb 26, 2015
Geoff Lawton documents a permaculture project that turned barren Jordanian desert into green, productive land. It covers the techniques he used.
Cited in climate and carbon-removal threads as an inspiring example of re-greening deserts.
5 comments from Hacker News
>You don't mention that trees also regulate the local microclimate; they tend to make rain, for example. Good point. I'm usually so eager to mention that, too! Trees regulate not only the microclimate, but the macroclimate as well. Isotopic analysis shows that about 80% of all terrestrial rainfall is caused by transpiration from trees and other plants. Trees essentially act as a giant inland irrigation network, using solar power to transport water via the airstream to power the water cycle. [LINK] So trees cause rain. This explains why deforestation causes desertification. I would also recommend the excellent Greening the Desert documentary for an example of the reverse process. this video
Permaculture is going to become a very important subject for study. I have recently gotten interested in the subject and the results have been amazing even in very unpromising conditions. Geoff Lawtons work in Jordan is inspiring: this video
I think you need a more encompassing approach. Permaculture might be something for you. They have developed specialized techniques for all climate zones. For example check out the "Greening the desert" project. this video
>Trees certainly work as a buffer in the sense that carbon in plants is carbon not in the atmosphere, but the amount you could hold is tiny in comparison to the amount that must be sequestered Is it? Let's do the math. Absorbing the 350 teratonnes of human emitted carbon[1] over the 8.4 billion hectares of Earth's non-tundra / non-desert land surface area[2] works out to... 42 tonnes per hectare. If we can green deserts[3] that drops to 30 tonnes. That's 30-40 trees per hectare, at 1 tonne per tree.[4] Or 3 kg per square meter of soil carbon, the equivalent of 25-35 cm of topsoil. More likely some combination of the two. Soil carbon is stored up to 40 meters down by deep rooted plants.[5] Most of our land management is via agriculture, so agriculture seems to be the only lever long enough to make a dent. Practically this implies transitioning from soil destroying tillage to soil building cover crops, long-distance imported fertilizer to in-situ fertility produced by soil organisms, and ecologically unstable monocultures to resiliant polyculture, agroforestry, and rotational grazing systems. The "gotcha" question is not whether we can replace our existing agriculture with these systems. The question is whether we can replace our existing agriculture with itself. Any unsustainable system is, by definition, not a viable replacement for itself. [1] [LINK] . [2] [LINK] [3] this video [4] [LINK] . [5] [LINK]
>most forest owners in the world don't know or don't have incentive to care So why limit yourself to existing forests? Instead of flooding deserts (using energy-intensive/land-intensive/wealth concentrating desalinization), we can re-green those same deserts[1], which restarts the "atmospheric river" that brings water to the interiors of continents. Isotopic analysis has revealed that trees powers the water cycle (by recycling rainfall that would otherwise flow off into the ocean) and causes 80% of Earth's terrestrial rainfall.[2] Compared to desalination this is far less costly (downside being, it's harder for Nestle et al. to profit off it). Yes Virginia, rain literally comes from trees! This partly explains why deforestation leads to desertification. [1] this video [2] [LINK]