Comparing the life cycle greenhouse gas emissions of dairy and pork systems across countries using land-use carbon opportunity costs

Report, 2020

Comparisons of the greenhouse gas (GHG) emissions of
livestock production in different countries using life cycle
analyses (LCAs) can provide insights into the changes in
farm practices that would reduce global emissions. Such
comparisons can indicate whether adopting the methods
of other countries would significantly reduce emissions.
This paper provides such an analysis. It originated with a
request from the Danish Agriculture and Food Council to
benchmark Danish pork and dairy emissions against other
countries, which could inform a strategy for achieving the
council’s announced goal of carbon neutrality by 2050.
One key issue is how analyses of this type factor in the
GHG costs of devoting land to agricultural use. Some LCAs
do not factor in any land costs, and others, in effect, only
factor in costs for crops originating from countries that
have ongoing expansion of agricultural land. As a result,
the livestock systems of some countries can be assigned
higher emissions than those of other countries because of
the origin of their crops, even if their production uses less
land overall.
This paper uses a different land-use approach to compare
the GHG emissions per kilogram of output across 13
countries for dairy, all of which are European, except for
Brazil, New Zealand, and the United States; and across
10 countries for pork, 8 of which are European. In some
cases, the analysis includes more recent data than other
studies to estimate production emissions, which are all
emissions other than land use GHG costs. This paper uses
a model that can help overcome data uncertainties by
incorporating processes that govern relationships between
feed and output per cow and pig.
This analysis also counts land-use carbon costs using
carbon opportunity costs. This approach recognizes that
when more agricultural land is used to generate food,
less land is available to store carbon in native vegetation,
which represents a true GHG cost.