Desert greening is the process of afforestation or revegetation of deserts for ecological restoration (biodiversity), sustainable farming and forestry, but also for reclamation of natural water systems and other ecological systems that support life. The term "desert greening" is intended to apply to both cold and hot arid and semi-arid deserts (see Köppen climate classification system). It does not apply to ice capped or permafrost regions. Desert greening has the potential to help solve global water, energy, and food crises. It pertains to roughly 32 million square kilometres of land.
Revitalizing arid landscapes offers numerous substantial advantages that have a positive impact on the environment, humans, and wildlife. These benefits encompass carbon sequestration, drawing in tourists, generating employment opportunities for local communities, stimulating natural rainfall patterns, and potentially luring back animal species that had migrated due to desertification. The prevention of land desertification is among the 17 sustainable development objectives outlined by the United Nations, a goal that can significantly advance the sustainable progress of desert greening. At present, tree planting stands out as the most efficient means to attain this objective. The process of greening a desert involves the transformation of arid landscapes into fertile, verdant lands with a rich variety of trees and plant species, creating a suitable environment for both humans and animals. It's a systematic approach to afforestation, aimed at converting degraded lands into economically valuable forests that can serve various purposes, including agriculture, carbon offset initiatives, research facilities, timber production, and ecotourism.
Planting trees plays a pivotal role in the advancement of desert greening. Nonetheless, the ongoing tree-planting endeavors are marred by certain shortcomings, such as limited effectiveness, labor-intensive requirements, challenging environmental conditions, and a low survival rate for young trees. Successful desert greening necessitates the establishment of a proficient management team with the necessary technical expertise, the implementation of water retention techniques such as sub-surface drip irrigation, the creation of high-quality nurseries capable of producing drought-resistant seedlings of economically valuable trees and crops, a commitment to environmental sustainability, and measures to control excessive grazing by nomadic herders. These measures are essential to ensure that the green belt created is not misused or subject to degradation.
Methods
Environmental remediation and ecoforestry
Planting trees (pioneer species) and salt-loving plants (halophytes), such as Salicornia Planting trees augmented by dew and rain harvesting technologies like the Groasis Waterboxx Regeneration of salty, polluted, or degenerated soils
Landscaping and green infrastructure
Ecoscaping; landscaping methods which reduce evaporation, erosion, consolidation of topsoil, sandstorms, and high temperatures Floodwater retention and infiltration (flood control)
Agriculture
Desert farming based on fossil groundwater, although not being sustainable
Farmer-managed natural regeneration
Greenhouse agriculture
Holistic management
Inland mariculture
Managed intensive rotational grazing
Permaculture in general – harvesting runoff rainwater to grow plant communities polyculture, composting or multitrophic agriculture Prevention of overgrazing Regenerative agriculture Seawater greenhouses and farming, for example, Seawater Foundation or the IBTS Greenhouse
Other
Prevention of firewood or charcoal use, respectively providing electricity for cooking
Water
Desert greening is substantially a function of water availability. If sufficient water for irrigation is at hand, any hot, cold, sandy or rocky desert can be greened. Water can be made available through saving, reuse, rainwater harvesting, desalination, or direct use of seawater for salt-loving plants. These different paths have unique features, i.e.: conserving water is a cheap solution. Reuse of treated water and the closing of cycles is the most efficient because closed cycles stand for unlimited and sustainable supply – rainwater management is a decentralized solution and applicable for inland areas – desalination is very secure as long as the primary energy for the operation of the desalination plant is available. Direct use of seawater for seawater agriculture is the most potent, only limited by the need for pumping up the water from sea level.