1. Plan can’t solve---other countries swamp US emissions.

Cattle, as large ruminants, hold an iconic position in many climate and sustainability discussions. The FAO estimated cattle numbers at 1.511 billion head in 2019 (FAOSTAT, 2020) and Fig. 7 shows global cattle numbers versus beef production for some of the major cattle producing countries and regions of the world. The United States is the largest single beef-producing country followed by Brazil. These two countries, along with Europe, collectively produced approximately 50% of the world's beef in 2020. However, this number does not reflect the distribution of global cattle populations. Brazil is the country with the largest number of cattle at 215 million head, with India coming in second at 193 million head. It should be noted that these figures are only for cattle. It does not include the world buffalo stocks of 204 million animals, of which 110 million head live in India. Likewise, Pakistan has almost the same number of buffalo (40 million) as cattle (48 million) totaling 88 million head. Likewise, beef production numbers are usually referring to cattle. If buffalo meat and edible offal from both are included in the production numbers, the values for India and Pakistan more than double from 0.9 and 1.1, to 2.9 and 2.4 MMt, respectively. Africa collectively is home to 361 million cattle, 24% of the global population, and 3.5 million buffalo located mainly in Egypt. In Africa, the agricultural sector is the largest sector of the domestic economy, and livestock are a crucial component of that sector and account for more than 70% of African agricultural GHG emissions. Ethiopia has 63 million cattle, the most of any African country, followed by Sudan and Chad each at 31 million head, Tanzania with 28 million head, Kenya and Nigeria each with 21 million head, Uganda with 16 million head, and Niger, South Sudan, South Africa, Mali and Burkina Faso each with 10–15 million head. Over 250 million cattle live outside of the top beef producing countries and the African continent, reflecting the fact that cattle are found throughout the world, in almost all climatic zones, with the exception of high elevations. They live in more than 200 countries around the world, and they have been bred for adaptations to heat, cold, humidity, extreme diet, water scarcity, mountainous terrain, dry environments, and for general hardiness. Cattle also produce milk, and in 2019, the world production of fresh cow milk was almost 715 MMt, of which 90 MMt was produced in India, and 36 MMt was produced in Africa. As with meat, a lot of milk is also produced by buffalo in India, 92 MMt according to the FAO, making India the largest dairy country, producing an estimated 21% (188 MMt) of the world’s 883 MMt of milk from all species in 2019. The highest cattle densities are found in India, the East African highlands (particularly in Ethiopia), Northern Europe and in South America (Fig. 8). Only 7% of beef (2% cattle population) is produced in intensive systems. Likewise, approximately 88% of milk production occurs within mixed crop and livestock systems, with only 12% being produced in intensive systems (Gerber et al., 2015). The majority of beef, 59% (63% cattle population), is produced in mixed crop and livestock systems, with the remaining 34% of total beef (35% cattle population) being produced on grazing systems. This later group can be further divided into intensive grazing systems that are found in tropical and temperate zones where high-quality grasslands and fodder production can support larger numbers of highly productive animals. These systems are mostly focused on food production, based on individual landownership, and supply about 20% of global beef production. The second category represents pastoral livestock systems that have developed in harsh environments, such as dry lands and cold areas, and which account for less than 15% of total beef production, but which support the livelihoods of 200 million households. These are driven by low animal productivity across large areas of arid lands, feed scarcity, and animals with low productive potential that are often used by smallholder farmers for other services such as draft power, manure and to manage household risk. It should be noted emissions attributable to animals used for draft power are typically excluded from the calculation of meat and milk emission estimates for that species (Gerber et al., 2013). These authors note the efficiency improvements based solely on saleable ASF products that result in herd size reductions could harm traditional farm household livelihoods due to the loss of the non-food goods and services provided by livestock. The developing world currently contributes 75% of global GHG emissions from ruminants and 56% of emissions from monogastrics (Herrero et al., 2013). There is a wide gap in emission intensities that exist on a global and regional scale (Fig. 9), and considerable variation between producers. It has been found that the environmental impact of producing the same product can vary by 50-fold (Poore and Nemecek, 2018). It is estimated that the potential for mitigating livestock emissions – CH4 in particular – by applying the practices of the top 10th percentile of producers with the lowest emission intensities in a given system, region and agro-ecological zone is between 30 and 35% (FAO, 2018). Chang et al. (2021) reported that 88–91% of the livestock CH4 emissions come from enteric fermentation by ruminants (i.e. cattle, sheep, goats, and buffaloes). They predicted that if there are no improvements in CH4 emissions per kg protein, then global livestock CH4 emissions will increase by 51–54% from 2012 to 2050. They estimated that improving production efficiencies in 10 countries (Brazil, China, India, Iran, Madagascar, Morocco, Niger, South Africa, Tanzania, Turkey) where a large increase in livestock production is projected and the current CH4 emissions per kg protein are high could contribute 60–65% of the global reduction in livestock emissions by 2050 (compared to a baseline where emission intensities are held constant in the future). They further found that efforts to improve production efficiency have a much greater potential for GHG mitigating effects than would demand-side efforts to promote balanced, healthy, and environmentally sustainable diets.