This commentary is part of a series organized by The Chicago Council's Global Agricultural Development Initiative and the World Food Prize to examine the relationship between biotechnology, sustainability, and climate volatility in the lead up to this year's Borlaug Dialogue.

By Dr. Rattan Lal
Rattan Lal, Ph.D., is a Distinguished University Professor of Soil Science and Director of the Carbon Management and Sequestration Center, The Ohio State University, and an Adjunct Professor of University of Iceland.

The extreme weather and drought the U.S. has experienced in 2012-13 may become a new norm and the impacts of global climate change will be even more severe in certain regions, known as global hotspots, in Sub-Saharan Africa, South Asia, and South America. These regions are already prone to declining agronomic yields and increased food insecurity due to the adverse effects of climate change.

The international community is now experiencing the effects of greenhouse gases trapped in the atmosphere. Between 1800 and 2013, the atmospheric concentrations of CO₂ increased by 43 percent.  This rapid increase is mainly attributed to the depletion of ecosystem carbon pools through common practices of the industrialized world, such as land use conversion, agricultural activities, fossil fuel combustion, and cement production. Agricultural activities in particular have been a predominant source of greenhouse gases (GHGs) through the human history. And more CO₂ was emitted from agricultural activities than fossil fuel combustion prior to the 1940s.

By 2050, global population is projected to surpass 9 billion people and, according to the United Nations Food and Agricultural Organization, agricultural productivity needs to increase by 60 percent to meet the future challenges. Faced with widespread soil degradation, dwindling fresh water resources, and extreme weather-related catastrophe, the prudent strategy is to adopt agricultural systems with built-in resilience against drought and other extreme climate events.

Climate-resilient agriculture is integral to any strategy of adapting to and mitigation the potentially catastrophic effects that climate change may have on the world’s agricultural production and global food security. And one of the focus areas should be on soil organic carbon (SOC) levels.

Soil organic carbon (SOC) is the carbon stored within soil, and it plays a vital role in the health and productivity of the soil. Typically Agro-ecosystems are depleted of their SOC by 25 to 30 percent in well-managed soils and by 70 to 80 percent in poorly managed soils. The critical SOC concentration in the surface 8-inch layer (20-cm depth) is about 1.5-2.0 percent.  Many smallholder farmers are already grappling with current levels at 0.1 percent or less in well-known hotspot areas. Such soils already have low adaptability against severe droughts because crops don’t always have sufficient water storage capacity coupled with shallow rooting depths. In such systems, soils with depleted SOC, may only be cultivated with minimal inputs. As a result, the soil can only produce small yields.  In contrast, sustainably managed soils can be a major sink of atmospheric CO2, produce high agronomic yields, and support growth and development of a farmer, and the community. 

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Sustainably managed soils can increase food security by producing greater yields on less land, with less water, and less energy.  At the same time by maintaining SOC concentration in the soil, such a system will be able to effectively adapt to global climate change.

In addition to maintaining SOC concentrations, some other climate-strategic adaptive approaches include:

• Preserving forests, savannas, prairies, and wetlands;
• Restoring degraded soils, agriculturally marginal lands, and wetlands;
• Recarbonizing the biosphere by sequestering C in soils and forests; and
• Adopting “sustainable intensification” on agricultural lands through producing more from less land area, low consumption of water and fertilizers, less input of energy, decreased emission of CO₂ and other GHGs, and narrowing the large agronomic yield gap.
• Using site-specific soil and water management practices for sustainable intensification such as conservation tillage, complex cropping systems including cover crops and agroforestry, integration of crops and livestock, integrated nutrient management combining organic manures and biological nitrogen fixation along with mycorrhizal associations and inorganic fertilizers, managing soil biota to enhance  disease – suppressive attributes, precision farming, water harvesting and recycling using micro irrigation etc.

Adoption of climate-resilient agriculture would be a major paradigm shift. Producing more crops and livestock per unit input of land, water, and energy in an ever-changing and variable climate, however is the key strategy to sustainably manage the food-climate-soil nexus and ensuring positive developments in global food security in the face of potentially catastrophic decline in agricultural productivity.