A review of whole farm systems models of greenhouse gas emissions from beef and dairy cattle production systems

Self Cite

The farm level is the most appropriate scale for evaluating options for mitigating greenhouse gas (GHG) emissions, because the farm represents the unit at which management decisions in livestock production are made. To date, a number of whole farm modelling approaches have been developed to quantify GHG emissions and explore climate change mitigation strategies for livestock systems. This paper analyses the limitations and strengths of the different existing approaches for modelling GHG mitigation by considering basic model structures, approaches for simulating GHG emissions from various farm components and the sensitivity of GHG outputs and mitigation measures to different approaches. Potential challenges for linking existing models with the simulation of impacts and adaptation measures under climate change are explored along with a brief discussion of the effects on other ecosystem services.Keywords: adaptation, farm-models, greenhouse gases, mitigation, ruminants ImplicationsWhole-farm models are valuable tools to study the feedback and feedforward interactions between mitigation of greenhouse gas (GHG) emissions and adaptation to climate change for ruminant-based production systems. All of the processes affecting GHG emissions and farm productivity involve the cycling of C and N within the farm, most of which will be affected by climate change. However, not all farm models include such responses to climatic drivers, and there is a need for further development and testing of the models under diverse climatic conditions. Modelling of the complex interactions between farm components and the environment, including the socio-economic aspects, is instrumental for providing strategic direction to the development of climate and food-related policies. Despite the contribution of nontemperate livestock systems to total global GHG emissions, there is a dearth of specific farm models to assess GHG emissions from these regions. Modelling of soil carbon (C) fluxes is still largely absent or very simplified in many studies even though soil C has the potential to be the largest source or sink of C for grassland-based livestock systems. IntroductionAccording to The Food and Agriculture Organization (FAO) (Steinfeld et al., 2006) livestock production systems contribute about 18% of global anthropogenic greenhouse gas (GHG) emissions. Livestock is also currently one of the fastest growing agricultural subsectors in developing countries (Thornton, 2010), with projections indicating that by 2050 worldwide animal production is expected to increase by 80% compared with 2005 (Alexandratos andBruinsma, 2012). Although demand for non-ruminant meat has been increasing more rapidly than that for ruminant meats and, consequently, the importance of grasslands in livestock production and trade has been declining, increased milk and beef demand, potentially produced via grassland-based systems, is expected to increase (Fiala, 2008;Thornton, 2010). It is thus projected that the global annual growth rate of beef until 2050 will be 1.2%, clos...

mentioning

confidence: 65%

Section: Model Evaluation and Uncertaintymentioning

confidence: 99%

Whole-farm models to quantify greenhouse gas emissions and their potential use for linking climate change mitigation and adaptation in temperate grassland ruminant-based farming systems

Prado

Crosson

Olesen

et al. 2013

Self Cite

“…Greater intensification of animal housing and livestock management can also contribute to decreasing the relative GHG emissions at an individual level. Intensification can be defined as the increased use of external inputs and services to increase the system efficiency which is typically associated with lower GHG Ei (Burney et al, 2010;Crosson et al, 2011). A reduction in the area per animal (increasing the stocking rate) or restricting access to pasture, are characteristic of intensive systems.…”

Section: Contribution Of Livestock To Global Greenhouse Gas Emissionsmentioning

confidence: 99%

Current available strategies to mitigate greenhouse gas emissions in livestock systems: an animal welfare perspective

Llonch

Haskell

Dewhurst

et al. 2017

Livestock production is a major contributor to greenhouse gas (GHG) emissions, so will play a significant role in the mitigation effort. Recent literature highlights different strategies to mitigate GHG emissions in the livestock sector. Animal welfare is a criterion of sustainability and any strategy designed to reduce the carbon footprint of livestock production should consider animal welfare amongst other sustainability metrics. We discuss and tabulate the likely relationships and trade-offs between the GHG mitigation potential of mitigation strategies and their welfare consequences, focusing on ruminant species and on cattle in particular. The major livestock GHG mitigation strategies were classified according to their mitigation approach as reducing total emissions (inhibiting methane production in the rumen), or reducing emissions intensity (Ei; reducing CH 4 per output unit without directly targeting methanogenesis). Strategies classified as antimethanogenic included chemical inhibitors, electron acceptors (i.e. nitrates), ionophores (i.e. Monensin) and dietary lipids. Increasing diet digestibility, intensive housing, improving health and welfare, increasing reproductive efficiency and breeding for higher productivity were categorized as strategies that reduce Ei. Strategies that increase productivity are very promising ways to reduce the livestock carbon footprint, though in intensive systems this is likely to be achieved at the cost of welfare. Other strategies can effectively reduce GHG emissions whilst simultaneously improving animal welfare (e.g. feed supplementation or improving health). These win-win strategies should be strongly supported as they address both environmental and ethical sustainability. In order to identify the most cost-effective measures for improving environmental sustainability of livestock production, the consequences of current and future strategies for animal welfare must be scrutinized and contrasted against their effectiveness in mitigating climate change.Keywords: animal welfare, climate change, livestock, mitigation, sustainability ImplicationsLivestock is a major contributor to climate change. In the context of an expected increase in the consumption of animal products, livestock producers must reduce their impact on the environment. A number of strategies have been proposed to reduce greenhouse gas (GHG) emissions from livestock, including ruminants. These strategies are based on changes in feeding, breeding and management practices. However, their implications for the animal's health and welfare still need to be explored. This paper tabulates and discusses the potential welfare hazards and benefits of implementing the most prominent strategies and identifies the most costeffective (GHG reduction v. welfare) strategies to mitigate climate change. Contribution of livestock to global greenhouse gas emissionsThe global livestock sector contributes significantly to anthropogenic GHG emissions. Direct emissions (through enteric fermentation and losses from manure) from livest...

“…As a result, there was a need to develop models for GHG emissions from Irish systems of production. To this end, Crosson et al (2011) undertook and published a review of whole-farm system models of GHG emissions from beef and dairy cattle production systems.…”

Section: Introductionmentioning

confidence: 99%

“…The case for adopting a whole-farm approach is strongly made by Crosson et al (2011). Intergovernmental Panel on Climate Change (IPCC) reporting protocols include GHG emissions that arise in agricultural systems in three IPCC sectors, namely, agriculture, land-use change and forestry and energy (IPCC, 1997).…”

Section: Introductionmentioning

confidence: 99%

The Carbon Navigator: a decision support tool to reduce greenhouse gas emissions from livestock production systems

Murphy

Crosson

O’Brien

et al. 2013

Self Cite

The Carbon Navigator has been developed to support the objective of reducing the carbon intensity of the dairy and beef sectors of Irish agriculture. The system is designed as a knowledge transfer (KT) tool aimed at supporting the realisation at farm level of the mitigation potential. The objective of this paper is to outline the potential role of KT in reducing greenhouse gas emissions in the context of a growing body of science, which identifies potential mitigation. The EU policy framework for agriculture and the environment is examined in terms of its effectiveness in supporting the reduction in emission intensity of agriculture. The important role for KT in reducing agricultural emissions is highlighted. The Carbon Navigator is introduced as a potential aid to achieving improved adoption of emission-reducing technologies and practices at farm level. The paper outlines the criteria guiding the selection of mitigation technologies in Irish ruminant agriculture, describes the technologies and practices included in the system and outlines the basis for their inclusion. The approach of developing the Carbon Navigator to integrate into existing infrastructure and data systems as well as into the existing KT systems is outlined.