Climate metrics and the carbon footprint of livestock products: where’s the beef?

Abstract

The livestock sector is estimated to account for 15% of global greenhouse gas (GHG) emissions, 80% of which originate from ruminant animal systems due to high emissions of methane (CH 4 ) from enteric fermentation and manure management. However, recent analyses have argued that the carbon footprint (CF) of ruminant meat and dairy products are substantially reduced if one adopts alternative metrics for comparing emissions of GHGs-e.g., the 100 year global temperature change potential (GTP 100 ), instead of the commonly used 100 year global warming potential (GWP 100 )-due to a lower valuation of CH 4 emissions. This raises the question of which metric to use. Ideally, the choice of metric should be related to a climate policy goal. Here, we argue that basing current GHG metrics solely on temperature impact 100 years into the future is inconsistent with the current global climate goal of limiting warming to 2°C, a limit that is likely to be reached well within 100 years. A reasonable GTP value for CH 4 , accounting for current projections for when 2°C warming will be reached, is about 18, leading to a current CF of 19 kg CO 2 -eq. per kilo beef (carcass weight, average European system), 20% lower than if evaluated using GWP 100 . Further, we show that an application of the GTP metric consistent with a 2°C climate limit leads to the valuation of CH 4 increasing rapidly over time as the temperature ceiling is approached. This means that the CF for beef would rise by around 2.5% per year in the coming decades, surpassing the GWP based footprint in only ten years. Consequently, the impact on the livestock sector of substituting GTPs for GWPs would be modest in the near term, but could potentially be very large in the future due to a much higher (>50%) and rapidly appreciating CF.

Environmental sustainability assessment of the manufacturing process of a biological active pharmaceutical ingredient

“…It is estimated that the livestock sector is responsible for around 15% of the total greenhouse emissions globally. 39 As mentioned, in the ELPS considered in this study the impact of deforestation is not included, however it has an impact on carbon emissions due to activities associated to the deforestation such as burning of felled vegetation and factors like soil carbon and carbon sequestration losses. 38 The resource-based method results show a wider range due to the heavy impact given to land occupation in the CEENE methodology.…”

Comparison of five methods for the estimation of methane production from vented in vitro systems

“…Methane is a potent greenhouse gas with a global warming potential that is 34 times greater than that of carbon dioxide . The livestock sector is responsible for producing approximately 15% of global greenhouse gas (GHG) emissions . Currently, 80% of the GHG emissions generated by livestock consist of methane from enteric sources .…”

“…The livestock sector is responsible for producing approximately 15% of global greenhouse gas (GHG) emissions . Currently, 80% of the GHG emissions generated by livestock consist of methane from enteric sources . Enteric methane is produced when ingested plant compounds are fermented in the rumen to produce intermediary products such as carbon dioxide and hydrogen, which are then captured by the rumen methanogens and converted to methane, and this is then excreted mostly by eructation …”

“…[3][4][5] Currently, 80% of the GHG emissions generated by livestock consist of methane from enteric sources. 5,6 Enteric methane is produced when ingested plant compounds are fermented in the rumen to produce intermediary products such as carbon dioxide and hydrogen, which are then captured by the rumen methanogens and converted to methane, and this is then excreted mostly by eructation. [7][8][9] Several strategies have been proposed for reducing enteric methane production (MP), and in order to assess these strategies it is important to accurately quantify MP.…”

Lightweight mid-infrared methane sensor for unmanned aerial systems

“…Methane is a strong greenhouse gas and plays a key role in determining the climate impact of sources such as wetlands, livestock, and oil and gas equipment [1][2][3]. There is a continuing need for technology to better understand and track the sources and sinks of methane at the local scale.…”