By Vanessa Meadu and Gareth Salmon

The negative environmental and climate impacts of livestock production have been well-publicised in recent years, but stories framing livestock as universally bad for the environment paint an incomplete picture as far as data is concerned. These narratives ignore huge variations in the impacts of different livestock species, products and production systems, and erase enormous differences among regions. We must understand the best available data on these interactions in order to properly manage livestock production and reduce the worst environmental impacts, while increasing benefits that livestock bring to environment and society.

Livestock data ignites debate about environmental impacts

Back in 2006, the UN Food and Agriculture Organization (FAO) published the report Livestock’s Long Shadow, which aimed to quantify the global livestock sector’s negative impact on environmental issues (including land degradation, atmosphere and climate change, water use and pollution, and biodiversity) and the potential for the sector to offer solutions. The report’s conclusions relating to the livestock sector’s greenhouse gas (GHG) emissions reverberated widely, due in part to erroneous comparisons between both direct and indirect emissions from livestock and direct emissions from transport. The report’s authors have since adjusted their analysis, revising down total direct and indirect livestock emissions from 18 percent to 14.5 percent, and have elaborated that direct livestock emissions make up 5 percent of human-made emissions, a far cry from the 14 percent direct emissions contributed by the transport sector. Nevertheless, these numbers ignited global debate, and the contribution of livestock to the climate crisis remains a hot topic.

Breaking down the numbers

Major global studies have quantified the GHG emissions attributed to livestock production (including assessments for ruminant, dairy specific, poultry and pig production). Most of these data-rich publications come from the FAO, but other groups have also studied and demonstrated the potential scale of the sector’s contribution to climate change, including the International Livestock Research Institute (ILRI), The International Institute for Applied Systems Analysis (IIASA), and the Commonwealth Scientific and Industrial Research Organisation (CSIRO).

A key message from global datasets is that hidden within the significant scale of total emissions is tremendous variation in GHG emissions attributed to units of livestock produce from different sources. This is termed the emissions intensity of production (e.g. kg CO₂eq/kg protein). As part of the Livestock Data For Decisions Livestock Fact Check series a Fact Sheet was produced to dig into the variation behind the commonly referenced 14.5% as livestock contribution to human GHG emissions.

Visualisation: Livestock and greenhouse gas (GHG) emissions by region, species, production systems, and products

 

A new visualisation breaks down livestock GHG emissions by region, species, production system and product. Users can explore how emissions vary depending on the context or location, and further dig into the data to understand how these differences play out.

Production efficiency – a more useful metric

Livestock GHG emissions are best understood in terms of ‘efficiency of production’ – the more protein (or any other measure of value for livestock products) that can be produced for the least emissions, the lower the emission intensity. The LiveGAPS project led by CSIRO demonstrated that efficiency of production varies significantly amongst livestock production systems in Low- and Middle-Income Countries. This means that there are opportunities to improve production efficiency, to produce the same amount of livestock products with less climate impact, or reduce the climate impact of any increases in production. The data demonstrating this variation is used to suggest that livestock can be part of the solution in tackling climate change. A recent paper also suggested that innovative solutions will play a part in reducing environmental impacts.

The challenge of modelling reality

Due to the scale and complexity of the economic, ecological and social systems requiring comprehension, data quantifying global contribution of livestock to GHG emissions is based on statistical models that are designed to reflect reality. For instance the Global Livestock Environmental Assessment model. As the infamous quote goes “All models are wrong, but some are useful”.

Models require data, which for the livestock sector is a challenge, and the very reason LD4D and livestockdata.org exist. Models also require their creators to define a scope and make certain assumptions about the way the world works. As such, there is risk that reality will be unfairly, inefficiently or dangerously interpreted as highlighted by a recent analysis by the Oxford Martin School.

Putting it all together

Discussions and decisions about livestock and environment need to take into account production efficiency and also carefully consider the data on benefits that livestock bring to people and society. There is a good body of evidence around livestock and human nutrition and livestock and economy. There will always be some trade-offs among these objectives. In some cases, it may be necessary to increase production to meet nutritional needs, especially among vulnerable populations in Low- and Middle-Income Countries. In other cases it may be appropriate to reduce consumption of animal products, for example in rich industrialised countries where over-consumption is an issue.

• Watch a video from Prof Mario Herrero: “Can we feed the planet, and stay within planetary boundaries?”

Want more data and evidence?

The newly launched livestockdata.org has a content theme dedicated to promoting data and resources relating to the livestock sector’s interaction with the environment. Suggestions on resources or data to promote are always welcome – please get in touch.

Vanessa Meadu is the Communications and Knowledge Exchange Specialist for SEBI – Supporting Evidence Based Interventions. Gareth Salmon is a Researcher with SEBI. SEBI facilitates the Livestock Data for Decisions (LD4D) Community of Practice and manages livestockdata.org.

Header photo: Dairy cattle in Isingiro District, Uganda, part of the ILRI Program for Climate-Smart Livestock systems (PCSL). Photo: S. Leitner (ILRI) (source)