A few related points
This paper discusses the linkages between burgeoning demand for livestock products, growth in livestock production, and the impacts this may have on natural resources, and how these may both affect and be affected by climate change in the coming decades. Water and land scarcity will increasingly have the potential to constrain food production growth, with adverse impacts on food security and human well-being.
Climate change will exacerbate many of these trends, with direct effects on agricultural yields, water availability, and production risk.
In addition to market forces that increase production costs of livestock production through appropriate pricing of greenhouse gas emissions and the changes in consumer purchasing decisions brought about by such economic changes, health and ethical considerations are likely to play an increasing role in modifying consumption patterns of livestock products, particularly in more developed countries.
Competition for Grain
This rising demand for meat and milk is expected to increase prices for maize and other coarse grains and meals used for animal feed. It will also divert agricultural production away from crops and towards livestock feed, reducing cereal supply for human consumption. Water demand to produce fodder for animals may compete directly with irrigation for the production of crops for multiple uses. This particularly hits poor consumers, as the price of cheap staple crops will rise.
Competition for Water
Globally, each person consumes 30-300 l of water per day for domestic purposes, while it takes 3,000 l per day to grow each person's food (Turner et al., 2004). Water scarcity is a globally significant and accelerating condition for 1-2 billion people worldwide, resulting in problems with food production, human health, and economic development. By 2025, 64% of the world's population will live in water-stressed basins, compared with 38% today .
The increases in livestock numbers that will be needed to meet the demand for livestock products have large potential impacts on water resources. But as Peden et al. (2007) note, livestock-water interactions have been largely neglected in both water and livestock research and planning to date.
Competition for Land
Over the last 20 years, large forest conversions have occurred in the Amazon Basin, South East Asia, and Central and West Africa. Cropland has expanded significantly in South East Asia and in parts of West and Central Asia, the Great Lakes region of Eastern Africa, the southern Amazon Basin, and the Great Plains of the United States. Agriculture now occupies about 40% of the global land surface.
The more intensive mixed systems in some regions of South Asia, for example, are already feeling the pressures of increasing human population and livestock product demand, as production factors are seriously limiting production as land per capita decreases significantly.
The conversion of forests and other natural habitats to cropland and pastures has been rapid, especially over the last 150 years. Livestock production can play an important role in deforestation. In recent times, the strongest link has been in Latin America, where extensive cattle grazing has expanded mostly at the expense of forest cover. It is estimated that by 2010 cattle may be grazing some 24 million hectares of land that was forest in 2000.
Livestock are having widespread direct and indirect impacts on biodiversity, via the increasing demand for and consumption of livestock products.
4 key syndromes on biodiversity loss occur:
- The first syndrome, extensive dryland syndrome, where rangelands are contracting to make way for cropping and settlement, with significant impacts on biodiversity.
- The second syndrome is centered on dryland key resources such as towns, markets, riverine areas and wetlands, where unusually high numbers of people and livestock gather. In such places, livestock grazing is heavy, wildlife are all but excluded, and only plants tolerant of heavy grazing thrive.
- The third, a syndrome of wetter environments, is the deforestation / reforestation syndrome, where the presence of pastures indicates that there has been massive biodiversity loss in the conversion from tropical rain forest; or alternatively, the pastures constitute a valuable source of biodiversity in the cases where abandoned pastures are being reforested in the temperate regions.
- The fourth syndrome occurs in forests and woodlands that are used even more intensively. In this syndrome, invasive species are pervasive, there are no wildlife, nutrient pollution is common, and biodiversity is simplified and homogeneous from place to place. This represents almost complete replacement of the native ecosystem, with strong and negative implications for biodiversity.