Desertification
What is it?
Approximately 1 billion humans populate the arid and semiarid environments, which cover 40% of the global land surface, that are currently threatened by the process of desertification (Verón et al., 2006). A serious threat to the environment and human welfare, desertification is most authoritatively defined as land degradation in arid, semi-arid, and dry sub-humid areas as a result of many factors including climatic variations and human activity (Geist & Lambin, 2004).
Essentially, water-scarce drylands of the world undergo land-degradation, which in turn degrades its productivity.
The complexity of this process provides for ongoing debates regarding its causes, consequences, and its operation as a socioeconomic mechanism (Verón et al., 2006). The foundational understanding of what causes the degradation of agriculturally used drylands consists of excessive human exploitation combined with the ecological fragility of a particular system (Kassas, 1995). Driving forces of human exploitation include an escalation of needs because of increasing population, development of commercial economies as opposed to maintaining subsistence economies, and overall economic and national development that exacerbates conflicts over market prices and land and water use. These aggressive human processes interfere with inherently fragile dryland ecosystems that already experience variable rainfall, thin plant cover, and skeletal soils (Kassas, 1995).
In the most general sense, desertification occurs because human pressures further damage an environment that otherwise would have survived natural fragile conditions.
Local & Global Impacts
Land degradation is a process that occurs world-wide, and desertification is the degradation of drylands, millions of hectares of which exist across all continents except Antarctica (Kassas, 1995). Not only does this form of land degradation directly impact populations in dryland areas, but it is an increasingly important element of global climate change.
Desertification can significantly affect regional climates, animal biodiversity, and induce erosion and “aridification” processes, which cyclically contributes to desertification. It is considered to physically exist in these forms: vegetation loss due to agriculture or other land use, shrub encroachment, and grass invasion into fireproof shrublands. Through ecological connectivity, these forms of desertification interact and can be linked to forces like climate change, land use, and vegetation cover. Examples include emission of nitrogen into the atmosphere from dust movements as a result of degradation, or increased fuel beds for wildland fires and erosion as a result of grass invasion (Okin et al., 2009).
Drylands are heavily connected to the rest of the natural world through the movement of fire, water, and soil, and understanding the degree of connectivity is imperative for effective control and reversal of desertification.
The future
The management of desertification requires corrective actions that create a foundation for the development of sustainable land and water resources (Kassas, 1995).
In raising potential plans to combat desertification, a case study on The Great Plains region in the U.S., in which drought occurred with little notice or damage from 1930-50, is often referenced. During this time, corrective measures explored under the breadth of federal land policy, federal financial support, and investment into developing the publics’ understanding of ecology all aided in reducing the effects of degradation. Examples of sustainable actions include The Taylor Grazing Act of 1934, which established federal control over the suitable number of animals across the land, as well as large-scale-water-management projects in Boulder and Shasta that provided irrigation for extensive farmlands.
However, our climate is shifting as a result of modernizing processes, meaning desertification requires continuous studying. The growth of remote satellite sensing tools and increased understanding of ecosystem ecology represents a new, modern opportunity to adequately assess desertification anywhere in the world at any scale (Verón et al., 2006).
Desertification will exist as long as humans continue to interact with the environment in an unknowingly damaging manner, so any action, whether we draw upon past successes or newly available technology to reduce the connected pathways that induce desertification will be an effort to combat this complex issue.
Creative Commons. (2020). [Texas Panhandle Drought]. Retrieved 2020, from https://newsvibesofindia.com/world-day-to-combat-desertification-and-drought-2020-history-significance-and-celebration-25345/
Geist, H. J., & Lambin, E. F. (2004). Dynamic Causal Patterns of Desertification. BioScience, 54(9), 817. https://doi.org/10.1641/0006-3568(2004)054[0817:dcpod]2.0.co;2
​
IFPRI/Milo Mitchell. (2017). [Land degradation is a prominent problem in Senegal]. Retrieved 2020, from https://www.mamopanel.org/news/blog/2017/aug/17/why-better-soil-could-mean-peace-and-prosperity-af/
​
Jacobson, M. Z., & Jacobson, M. (2012). Preface. In Air pollution and global warming: history, science and solutions (pp. xvii-xviii). preface, Cambridge University Press.
​
Jacobson, M. Z. (2009). Review of solutions to global warming, air pollution, and energy security. Energy Environ. Sci., 2(2), 148–173. https://doi.org/10.1039/b809990c
​
Kassas, M. (1995). Desertification: A general review. Journal of Arid Environments, 30(2), 115-128. https://doi.org/10.1016/s0140-1963(05)80063-1
​
Okin, G. S., Parsons, A. J., Wainwright, J., Herrick, J. E., Bestelmeyer, B. T., Peters, D. C., & Fredrickson, E. L. (2009). Do Changes in Connectivity Explain Desertification? BioScience, 59(3), 237–244. https://doi.org/10.1525/bio.2009.59.3.8
​
Quiroga, M. (2009). [UNCCD Photo Contest 2009]. Retrieved 2020, from https://www.theguardian.com/environment/gallery/2010/dec/15/un-desertification-photo-contest
​
Verón, S., Paruelo, J., & Oesterheld, M. (2006). Assessing desertification. Journal of Arid Environments, 66(4), 751-763. https://doi.org/10.1016/j.jaridenv.2006.01.021