Part 2: Land Use and Livestock: The Desertification Debate

Desertification refers to the persistent land degradation in dry-land ecosystems resulting from various factors such as variations in climate and human activities (UNCCD, cited in WMO). Apart from the great number of natural factors contributing to desertification, it is often the result of long term failure to balance human demand for ecosystem services and the amount the ecosystem can supply (greenfacts.com). A growing world population is increasing pressures on dryland ecosystems such as livestock grazing for food, building materials, irrigations. In 2005, it was reported that 41% of Earth’s total area were occupied by drylands of which 88% were used for grazing (UNEP,1992). (see desertification map)

Source: Millennium Ecosystem Assessment

Overgrazing represents one of the main human activities contributing to desertification (Middleton, 1993). When a grazing land starts to loose its soil quality, plant diversity and starts to develop minimal land cover (Ibanez et al 2007), the land’s carrying capacity is exceeded by livestock overgrazing. The land is unable to support the excessive large number of herds grazing off it, causing an alteration in both quantity and quality of vegetation. Desertification related processes affect rainfall and cloud patterns, biodiversity as well as the global carbon cycle where damaged soil releases carbon back into the atmosphere (UN, 1977). For instance, the Millennium Ecosystem Assessment Report on Desertification (2005) shows how dust storms in China adversely affect Japan, the Korean peninsula and even influences air quality in North America.

Source: Chris Madden 

As I was researching on the topic, I came across a cutting edge debate on desertification to which I wish to reflect on in this second part of my post.

Despite the rather extensive academic scientific knowledge that is documented on livestock overgrazing as a cause of desertification (see above arguments), Allan Savory, a considerably renown Zimbabwean biologist suggests livestock grazing can put an end to desertification.

Now I dare not post the Ted Talk  (2015) on this blog for it contrasting all of its values and beliefs but I came up with a quick summary of what it said:

In brief, he argued that we could reverse global desertification by a 400% increase in livestock grassing and an introduction of holistic management and planned grazing system. If the grass does not decay biologically, then the soil begins to die. Traditionally farmers used to burn grass in order to remove dead materials so that the soil could regenerate. However he argues that this technique is a great source of pollution and consequently the only potential way to go about it is to use bunched and moving livestock to deal sustainably with this problem. He also claims that the hooves of animals break up the crust of algae that previously stopped the absorption of water into the land, and therefore their periodic trampling assures a good cover of the soil (Ted Talk, 2015).

My initial reaction to this talk was rather enthusiastic. We could continue eating meat (and even more of it) and at the same time stop desertification!  Savory had presented his theory in such a visual and simple manner that his holistic management seemed like a reasonable idea. However, I doubted some of his arguments:

-       Firstly he argued, that livestock should be re-introduced on to already 'desertified' land to enable “biological decay and soil regeneration” but what would animals feed on if they are introduced on deserted land?, would we have farm feed for them, causing an even greater amount of deforestation and desertification? 

-       Secondly, he talks about how hunting behaviours enables natural animal trampling.  Unfortunately for Savory, not all deserted areas of the world are being trampled by hunted animals and in fact most of these areas have lost all types of biodiversity, causing species to migrate to other areas of the world.

In response to these doubts, I researched for some potential critiques that arose from this talk. TheJournal of Agricultural System, published a review of experimental results on intensive rotational grazing (proposed through Savory’s holistic management) and its impact on grassland which proved that this technique in no ways improve soil hydrology or the general increase in vegetation production (Briske et al, 2013) to which Savory had claimed the contrary. Similarly, the InternalJournal of Biodiversity with important empirical evidence, proved the following:

“Ecologically, the application of holistic management principles of trampling and intensive foraging are as detrimental to plants, soils, water storage, and plant productivity as are conventional grazing systems" (Carter et al, 2014).

Furthermore, George Monbiot wrote post on his blog regarding the inaccuracy of Savory’s arguments, in which he recalls his conversation with Savory on his controversial desertification talk. Unlike Savory, Monbiot gives a wide range of evidence as to why his theory is scientifically impossible to reproduce. His main argument is that Savory’s statements are not supported by empirical evidence and that in the end his techniques to more harm than good. “If you intend to make a massive and extraordinary scientific claim, and build your position around it, you had better ensure that it has been properly tested, which is why the peer review process exists” - (Monbiot, 2015).

Source: edited by Kelly Nehr

It is important to remain open minded and critical when people claim to have found ‘the one last and only solution’ (Savory, 2015) to an enduring environmental problem. Unfortunately science is not as simple as it may sometimes seem to be, but on the bright side, here are some alternatives to consider in dealing with desertification: