The global warming crisis is forcing consideration of innovative and alternative approaches to climate mitigation and reversal. Simply going to a zero fossil fuel economy will not stop catastrophic consequences, even if such an about-face in energy use were achievable. At our current level of 400 ppm atmospheric CO2, we are already well beyond what has been deemed the maximum safe level for human habitation, 350 ppm (Hansen, 2008). Indeed, recent anomalous weather and warming related events, including the unexpectedly rapid loss of arctic sea ice (Maslowski, 2012), may indicate that “amplifying feedbacks” are already underway (Glikson, 2013; Torn & Harte, 2006). This situation, unfortunately, is not likely to be remedied with a simple return to 350 ppm. Doing so may only slow warming to the rate it was at in 1988, when it was last at 350 ppm, and evidence of impact was already alarming (Hansen, 1988; Shabecoff, 1988). In fact, warming will likely be worse in a future 350 ppm scenario, because the cumulative impacts will have weakened the planet’s potential to absorb excess heat. There is probably no actual reversal of warming until CO2 concentrations are brought back to preindustrial levels, well under 300 ppm.

To accomplish this essential and herculean task requires not only cessation of fossil fuel emissions, but also a drawdown of approximately 200 gigatons carbon (200 Gt C) from the atmosphere. It is clear that the only conceivable safe and long-term solution for this is through global ecosystem restoration. This will include forests and wetlands, but particularly, also, grasslands, including prairies and savannas, where carbon is sequestered through the roots of perennial plants and bound in organic soil compounds for decades to millennia (Rabbi, 2013). In total, grasslands comprise the largest ecosystem on Earth and are major stores of terrestrial carbon. By various estimates, they cover between 26% and 40% of the world’s land while containing 20% to 35% of soil carbon (FAO, 2010; Ramankutty, Evan, Monfreda, & Foley, 2008; R. White, Murray, & Rohweder, 2000). Even small percentage increases in soil carbon worldwide can dramatically reduce atmospheric CO2 concentrations.

Entering this conversation is the practice of Holistic Planned Grazing (HPG), in which livestock are herded in a fashion that replicates the beneficial grazing, trampling, dunging, and nutrient recycling dynamics with which wild herding ruminants coevolved with perennial grassland plants and carbon-rich soils (Savory & Butterfield, 1999). Decades of anecdotal evidence and recent studies suggest this practice has great promise, both for ecological functioning, including plant growth and hydrology, and for increasing soil organic carbon (SOC) (Dagget, 2005; Earl & Jones, 1996; Gill, 2009; Howell, 2009; Norton, 1998; Stinner, Stinner, & Martsolf, 1997; Teague et al., 2011; K. T. Weber & Gokhale, 2011). For example, Teague (2011) showed that land managed under a restorative grazing regimen (multi-paddock with ecological goals) had a far higher SOC value than land on a similar site managed with traditional (heavy continuous) grazing. When factoring across all soil profile depths measured, this added carbon equated to a 30 t C/ha.  Additionally, Weber (2011) showed that land under a restorative grazing regimen (simulated Holistic Planned Grazing, SHGP), had significantly improved water holding capacity, measured as percent volumetric-water content, %VWC, when compared with traditionally grazed lands.  Hydrological functioning is correlated with soil carbon (Feger & Hawtree, 2013; Franzluebbers, 2002).

In the absence to date, however, of robust HPG carbon data, this paper infers soil-carbon sequestration potential, based on known SOC values for representative biomes (DOE, 1999; FAO, 2009; Hiederer & Kochy, 2011; Lal, 2004b; UNEP, 2009; R. White et al., 2000; W. White, Wills, & Loecke, 2013), and, in light of this innovative approach to grasslands restoration, reevaluates current estimates on soil C losses and sinks (Lal, 1999, 2004b, 2011). The investigation shows that grassland carbon capture may be far greater, and more rapid, than what has previously been considered possible, where restoration via enhanced ruminant impact had not been factored. Managing livestock in this entirely new way, not just as consumers of grass, but also as essential elements in ecosystem balance, and with restorative goals as an intention, enables significant upward estimation of soil-carbon sequestration potential. Although there are many uncertainties, and future research is needed, these considerations broaden the narrative on climate change mitigation.