October 30, 2013
| Photo by Karl Thidemann
The Center for International Environment and Resource Policy (CIERP) hosted Seth Itzkan, President of Planet-TECH Associates, on October 30 for a talk entitled “Climate Mitigation 2.0 – The Promise of Restorative Grazing: Counter-Intuitive Approaches for Reversing Desertification and Global Warming While Meeting Human Needs.”
The lecture was part of CIERP’s Agriculture, Forests, and Biodiversity Program, and continued the discussion begun at Fletcher last year with a visit by Allan Savory, Founder and President of Savory Institute, who will return to Fletcher for a public event and closed student workshop on November 22-23. Savory and Itzkan research and advocate for holistic management of natural resources.
Itzkan began his lecture by defining “Climate Mitigation 2.0” as the idea of restorative development, in contrast to “Version 1.0,” which was primarily focused on reducing use of fossil fuels. He argued that livestock, properly managed, can be a facsimile for wild herding ruminants – and should thus be recognized as a goal of sustainable development efforts.
Grasslands are the largest ecosystem on the surface of the earth. At approximately forty percent of the landed surface, grasslands are on par with forests in terms of storage of terrestrial carbon. Itzkan noted one important difference, however: this carbon is stored in the soil, not the vegetation. “There’s more carbon in the soil than in all vegetation and the atmosphere combined.”
The relevant metric in recovery of degraded grasslands, explained Itzkan, is density of grass cover. This density serves to capture moisture and reverse desertification. “Desertification equals carbon loss, so this is a climate issue…(soil) carbon is a powerful tool in regards to the climate conversation.” The more carbon in the ground, the greater the ability to retain water and replenish the water table, thus surface water remains longer into the dry season. The density of grass cover ensures that water is pulled into the table rather than running off.
Itzkan cited the importance of seminal works such as Lal (1999) and White et al. (2000) in advancing public understanding of the scale of cropland’s effects on carbon emissions. Lal’s research focused on loss of carbon and the negative implications thereof, but Itzkan argued that we can use the same research as a measure of restoration potential. Lal shows that a “new equilibrium” is obtained in soil after a loss of 20-50 Mg C/ha (Mega-gram or tonne per hectare), so, said Itzkan, can the opposite also be true? Can we achieve a new equilibrium working in reverse, adding carbon, instead of losing it?
Itzkan highlighted the fact that cropland is only twenty percent of total grasslands, so holistic grazing represents a large-scale opportunity for climate mitigation. If all 5.2 billion hectares of grasslands were managed for restoration, sequestering between 25 and 60 tons carbon per hectare, the total sink potential would be 130 to 312 GtC, or the atmospheric equivalence of 61 to 147 parts per million CO2.
Itzkan presented visual evidence from a case study in Zimbabwe, where people are using their own animals to regenerate grazing land and water flow. Photos clearly demonstrated a rise in the elevation of the water level during the dry season. Surface pools on the Dimbangombe River were now present in the dry season 1.5 km upstream, and with an increased elevation of 10 meters, from where the previous dry season high water point had been. This occurred in concert with a four-fold increase in the number of livestock – grazing on vegetation that had become noticeably denser as the years progressed. In one location, water plants, such as reeds, were proliferating sideways from the stream. Itzkan explained that these plants were taking advantage of enhanced soil moisture.
In a short video clip, Elias Ncube, Training Manager from the Africa Center for Holistic Management, contrasts prior water shortages with the current level of surface water, stating, “We have changed this place into a kind of wetland…we now only need a pump to supply water for human consumption,” not for animals, as before.
Itzkan then paused to address the obvious question being held by the audience: how is this possible? Conventional wisdom holds that animal husbandry depletes water resources and vegetation.
However, grazing animals are an essential part of the grasslands ecosystem. “The soil needs animals,” Itzkan reminded us, “Animals do not overgraze on their own. In nature, predation encourages natural movement.” Unfortunately, so much of the historic ruminant impact has been lost with the reduction in wild herds, resulting in widespread desertification. We see this in photos of the American West: once large cattle ranches were established as sedentary settlements, replacing the free-ranging buffalo, densely vegetated prairie gave way to soil erosion and increasing dust storms. A stark black and white photo from 1880 depicts a veritable mountain of buffalo skulls piled high, serving to underscore this negative shift. Itzkan argued, “Overgrazing is a human invention, and it’s a question of management. Human mismanagement of animals has been causing desertification for hundreds of years.”
Itzkan ultimately remains positive, noting that this process can be reversed with proper management, by using livestock as a proxy for wild herds. He explained the process employed by the Africa Center for Holistic Management in Zimbabwe, showing several short video clips from his visits. A grazing plan allows managers to work backwards from desired end points. Land is mapped into paddocks, using natural boundaries [railway tracks, rivers, etc.] wherever possible. The kraal, or corral, protects from predators at night and concentrates dung distribution for a short duration.
Movement is key: 7-10 days is the optimum time for the kraal to be in any one location, maximizing the area covered in dung and plant litter without causing erosion. Thus the kraal must be mobile. The process of moving the kraal to a new location takes about four hours. Notes a rancher in one video, “It’s a quick fix [for bare ground]…there’ll be grass wherever you put the kraal.” Interestingly, the lion population is also increasing, further illustrating that the restorative benefits of holistic management are good for the entire ecosystem, including wild grazers and predators, said Itzkan.
Another holistic strategy consists of positioning the kraal directly on the crop field, thus eliminating the need to redistribute dung. This is known as a “treated” crop field, fertilized as a natural by-product of having the animals corralled at the site. In the video, we see this area subsequently transformed into a verdant vegetable garden.
Itzkan concluded by briefly discussing the concept of the “brittleness scale,” invented by Allan Savory, that is a measure of the distribution of humidity over the course of a year, as opposed to total rainfall. For example, areas with seasonal rainfall may get as much rainfall during a few months, say during the typhoon season, as a temperate area receives in a year, and yet, the majority of the year may be quite dry and hot. These areas, according to Itzkan, are “brittle environments that (in the absence of the large herbivores they evolved with) can’t self-regenerate the way a non-brittle environment (that has humidity year-round) can,” noted Itzkan. Degraded brittle environments can, however, be restored through proper livestock management, replicating the nutrient and moisture recycling and redistribution impacts of wild grazers.
On the subject of governance, Itzkan was less optimistic. Many governments enact policies that favor agriculture at the expense of pastoralism, encouraging fixed settlement while at the same time misdiagnosing grazing as the root cause of environmental degradation. He cited one example from South Africa in the 1970s, when people were jailed for having too many livestock, while in the adjacent territory of Lebowa, in a Holistic Management trial, livestock densities were increased, resulting in clearly visible improvements. Itzkan said this reveals the urgent need for further research into Holistic Management and advocacy to inform government policy makers on counter-intuitive innovations that may be efficacious for the environment and the climate.
“What I find very encouraging is this notion of restorative development,” noted Professor Moomaw in closing.
Summary by Kathleen Yaworsky, MALD Candidate F'15
Lal, R. (1999). "Soil management and restoration for C sequestration to mitigate the accelerated greenhouse effect." Progress in Environment Science 1(4): 307-326.
White, R., et al. (2000). Pilot Analysis of Global Ecosystems: Grassland Ecosystems. Washington, DC, World Resources Institute: 81.