Meat Eaters Guide: Methodology - Environmental Working Group

Post- farmgate emissions constitute just 10.4 percent, a relatively small portion, of the overall carbon
footprint of a kg of consumed beef. Processing (including freezing) accounts for nearly half of post-
farmgate beef emissions, but just 5 percent of total GHG emissions, followed by home cooking (4
percent), and domestic transport (1 percent) waste disposal (.3 percent).
2. Lamb Production
Figure 3. Beef: Production Dominates Greenhouse Gas Emissions
Production Emmissions
of Consumed Beef, 56%
The life cycle analysis was based on a typical Idaho lamb production system as well as two Ohio systems,
one average and the second highly productive. 51 The CO 2 e/per kg presented in our study is an
average of the three systems. Since roughly 50 percent of lamb is imported, we include ocean transport
(adjusted for 50 percent of lamb consumed) in our post-farmgate emission totals. However, all of
our GHG estimates for production are based on US lamb production systems.
a. Key Production and Modeling Details
• Lambs are ration-fed a diet of barley, corn, hay and some pasture grass.
• Ewes receive both feed rations and pasture grass.
• Finished lambs are sold for slaughter at roughly 125 lbs.
• As in the beef system, male animals (rams in this case) are purchased for use (at an approximate
ratio of 35 ewes per ram) and replaced every few years.
• Replacement ewes are raised within the herd (as in the Idaho lamb system) or purchased
from outside (as in the Ohio lamb system). Approximate replacement rate is 15-20 percent per
year.
• Co-products include wool, sheepskin, tallow and meat-and-bone meal, as well as culled or
replaced animals that were either sold or died.
Environmental Working Group Meat Eaters Guide: Methodology 2011 27