Environment Counts | Global environmental impact of livestock production in 2050
Author: Geoff Zeiss – Published At: 2011-11-20 10:54 – (901 Reads)
Current per capita levels of livestock production are unsustainable and are projected to become even more unsustainable in 2050. To be sustainable in 2050, greenhouse gas emissions per unit livestock protein produced will have to be reduced to 13%, biomass appropriation to 25%, and reactive nitrogen mobilization to 14% of year 2000 levels.
As of 2000, the livestock sector is estimated to have contributed 14% of anthropogenic greenhouse gas emissions (18% taking into account land use, land use change, and forestry), 63% of reactive nitrogen mobilization, and consumed 58% of directly used human appropriated biomass globally.
In a recent publication simple, but conservative, models have been used to estimate GHG, biomass appropriation, and reactive nitrogen mobilization under different scenarios for 2050.
Assuming levels of livestock production in 2050 as projected by the United Nations Food and Agriculture Organization (FAO), it is estimated that direct livestock-related greenhouse gas (GHG) emissions from meat, milk, and egg production will increase by 39%, biomass appropriation by 21%, and reactive nitrogen mobilization by 36% over 2000 levels.
To illustrate the range of options available for sourcing human dietary protein, three additional scenarios have been modeled. In the first poultry was substituted for beef. In the second it was assumed that human protein dietary requirements were provided by meat/eggs and dairy. In the third, human protein requirements were provided by soybeans. Assuming the United States Department of Agriculture (USDA) recommendations for kilogram per capita/year protein consumption levels, GHG emissions, biomass appropriation, and reactive nitrogen mobilization have been estimated for 2050 global population levels.
|GHG(Gt CO2-e)||Biomass(Gt C)||Reactive N(Mt Nr)|
It has been estimated that to prevent the Earth’s mean surface temperature rising above 2 Â°C, per capita GHG emissions must be reduced below one tonne per year by 2050. In 2000 the livestock sector already produced 52% of the sustainable threshold for anthropogenic greenhouse gas emissions. Similarly direct biomass appropriation by the livestock sector already consumed 72% of the sustainable threshold. The reactive nitrogen mobilization by livestock production exceeded the sustainability threshold by 117%. By 2050, these shares will increase to 70%, 88%, and 294% of the proposed sustainable thresholds. To be sustainable in 2050, greenhouse gas emissions per unit livestock protein produced will have to be reduced to 13%, biomass appropriation to 25%, and reactive nitrogen mobilization to 14% of year 2000 levels.