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

Rapport, 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  missions 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.