Comparing the FAO and Worldwatch Reports

The 2010 FAO report’s recommendations for addressing climate change through animal agriculture involve selective choices of feed crops and more intensive factory farming. According to the report, more success will come from changing production style and increasing industrial farming in third world countries. There is no mention any results will come from a policy that focuses on educating people about more healthy plant-based options of eating. Based on the authors’ work as livestock specialists, the report goes on to state that supplies of meat and dairy can be met without a systemic shift away from animal farming, but instead with better management of land, more intensification of farming, and more deforestation to meet feed crop requirements. If the focus is on simply improving the livestock sector, silvopasture or regenerative agriculture could have been examples suggested to improve the livestock sector.

The Worldwatch Report

Alternatively, the 2009 Worldwatch report indicates animal agriculture accounts for at least 51 percent of total human-induced GHG emissions in CO2 equivalent (32,564 million tons). The major culprits for this increase from the UN FAO reports are that the Worldwatch report factors in livestock respiration (CO2), undercounted methane, and overlooked land use. The report reviews both direct and indirect sources of GHG emissions from animal agriculture using a full life cycle assessment.

Unlike the FAO reports, the Worldwatch report followed the GHG protocol and included what is considered Scope 3 emissions. Scope 3 includes the many parts of the supply chain not owned by producers. Some other factors they used to determine the 51 percent are underestimated figures, while others are overlooked or already counted for but assigned to different sectors (i.e., deforestation for feed crops). The FAO reports also used outdated models of the carbon cycle and allocated categories like deforestation to other sectors, according to Paul Hawken, author of the New York Times bestselling book Drawdown: The Most Comprehensive Plan Ever to Reverse Global Warming (Penguin Books 2017).

Overall, the Worldwatch report suggests that the UN reports failed to develop a true whole life cycle assessment (LCA) of anthropogenic GHG emissions attributed to livestock. It concludes that promoting plant-based options should be a major focus for addressing climate change and biodiversity issues.

The FAO Reports

The 2013 FAO report only included the change in land use and deforestation over time from animal agriculture, which is relatively small, compared to the Worldwatch report, which includes the huge amount of land already in use for livestock production. The Worldwatch report also includes the deforestation factor related to livestock and livestock feed. There’s much debate on these points, which still require further comparison and research.

Additionally, the 2006 and 2013 FAO reports fail to include an entire category that is increasingly detrimental to the environment. They excluded all aquatic animals farmed for human consumption and livestock feed. Fish farms, for example, can generate significant coastal pollution in the form of excess feed and manure. Escaped fish and disease from these farms can completely deplete wild fisheries.

A 2008 Worldwatch Institute article found the following:

A fish farm with 200,000 salmon releases nutrients and fecal matter roughly equivalent to the raw sewage generated by 20,000-60,000 people. Scotland’s salmon aquaculture industry is estimated to produce the same amount of nitrogen waste as the untreated sewage of 3.2 million people – just over half the country’s population.

Land-based fish farming is not any better. This method has shown to produce significant ecological changes downstream, reducing biodiversity and killing pollution-sensitive species. Overall, fish farming is an inefficient way to feed the world. To raise one pound of salmon, you need over two pounds of wild fish to produce its feed. It is estimated that aquaculture and fish farming is already producing nearly half of humans’ entire seafood consumption, yet there is a lack of standards for what is “good” fish farming and how it can be done sustainably. All this said, the damage caused by animal agriculture needs to include fishing.

The FAO conclusions lack insight into groundbreaking innovations and alternatives to animal farming. The 2006 FAO report even stated, “the principal means of limiting livestock’s impact on the environment must be… intensification.”

New Percentage of GHG Emissions from Animal Agriculture



FAO’s conclusion that animal agriculture’s contribution to anthropogenic global GHG emissions of 14.5 percent is significantly too low. Even if one wants to use the outdated carbon cycle calculations of methane’s GWP or exclude the vast amounts of land use for feed or grazing, that percentage is still too low. There needs to be more research on the respiration of animals and if it has caused a decline in the earth’s photosynthetic capacity and is therefore no longer offset by previous carbon sequestration. More research like this that looks at various examples, instead of making generalizations, is also needed on the recent increases in volatilization in soil carbon based on common animal grazing methods.

A recent analysis published in Science showed that 83 percent of all farmland is used for animal agriculture.

The inclusion of carbon-storing benefits of land better purposed, for example, re-forested, would shift total anthropogenic GHG emissions attributed to animal agriculture well above the FAO’s 14.5 percent. A 2018 report published in Science, “Reducing food’s environmental impacts through producers and consumers,” concluded that the personal contribution to this 14.5 percent would effectively be eliminated on a vegan diet.

Factoring in changes in land use for increased carbon storage on a vegan diet would reduce one’s total personal GHG emissions by 30-50 percent.

A critique of the Worldwatch report makes the point that transportation does not get a full life cycle analysis and so cannot be compared apples-to-apples with the livestock industry. However, as the authors of the Worldwatch report allude to in this response article, the reason why transportation and energy sectors lack full life cycle analyses can be explained.

The most widely-accepted protocol for counting GHG emissions, the Greenhouse Gas Protocol, mandates counting emissions from both direct and indirect sources (other industries), which can result in double-counting. However, the transportation and energy sectors were not done in this way because the guidance and standards set by the Greenhouse Gas Protocol outline that items should only be double-counted when something can be realistically done to reduce them.

Immediate overhaul of the livestock industry through production and consumption can have immediate benefits by looking at the direct and indirect emissions while the same cannot be said about the transportation industry’s indirect emissions. As will be shown, immediate replacement of animal- to plant-based alternative foods can be done relatively quickly, and this is a unique solution for this industry. This transition can be done through a voluntary decision from the consumer to choose plant-based options, or if it becomes pressured from industry and government as a manner to address climate change.