Climate Change and ICLS
 

Integrated Crop-Livestock Systems and Climate Change

 

The livestock sector has expanded rapidly in recent decades and will continue to do so as demand for meat and dairy products continues to grow. An increase of up to 68 percent by 2030 from the 2000 base period has been estimated and this is mainly driven by population and income growth in developing countries (FAO, 2006. World Agriculture: towards 2030/2050). Livestock is also the world’s largest user of land resources, with grazing land occupying 26 percent of the earth’s ice-free land surface, and 33 percent of cropland dedicated to the production of feed (FAO, 2009. The State of Food and Agriculture: Livestock in the Balance). The quick expansion of the sector is a cause of overgrazing and land degradation and an important driver of deforestation. It is also responsible for methane and nitrous oxide emissions from ruminant digestion and manure management, and is the largest global source of methane emissions. However, the carbon footprint of livestock varies considerably among production systems, regions, and commodities, mainly due to variations in the quality of feed, the feed conversion efficiencies of different animal species and impacts on deforestation and land degradation (FAO, 2010. Green House gas emission from the Dairy Sector. A life Cycle Assessment). Significant productivity improvements are needed for developing countries to meet growing food security and development requirements, while minimizing resource use and GHG emissions from production.

 

Partitioning of milk production and greenhouse gas emissions over livestock production systems and climatic zones

A study on greenhouse gas emissions from the dairy sector has shown that, although grassland based and mixed systems* both contribute around 50 percent to, grassland based systems, on average, account for 60 percent of the global sector’s emissions, whereas mixed systems are characterized by a lower emission intensity, and are thus estimated to account for only 40 percent of emissions. The average emissions from grassland based systems are 2.72 kg CO2-eq. per kg of fat and protein corrected milk (FPCM), compared to an average of 1.78 kg CO2-eq. per kg of FPCM, in the mixed systems. Within the grassland systems, most of the milk production is found in temperate regions, which also includes the tropical highlands. The share of milk production in the temperate regions (grassland and mixed) is larger than their share in the total emissions, indicating a lower emission per kg of milk than the average.

 

*Mixed farming systems: are those systems in which more than 10% of the dry matter fed to livestock comes from crop by-products and/or stubble or more than 10% of the value of production comes from non-livestock farming activities (Seré and Steinfeld, 1996).

Land used for livestock production, including grazing land and cropland dedicated to the production of feed, represents approximately 70 percent of all agricultural land in the world. Overgrazing is the greatest cause of degradation of grasslands. Improved land management practices would help to achieve a balance between competing demands for animal food products and environmental services. Improved pasture management and silvopastoral systems are effective ways to conserve the environment and mitigate climate change. Recent linking of pasture regeneration policies and programmes to no-till based integrated crop/pasture/livestock systems in Brazil appears promising for both farmers and the environment. Sustainable intensification and improved manure management are further options to reduce GHG emissions per unit of livestock product, and the use of biogas from animal waste can reduce dependence locally on fossil energy.