Food companies and retailers want to list the “carbon footprint” of food products, but calculating carbon emissions from a food-production system, cattle specifically, is more complex than it might seem, The Wall Street Journal reports.

“Few products demonstrate the messiness of this effort (to measure a product’s environmental impact) more than a simple carton of milk,” The Wall Street Journal article said. “Several studies in various countries have already sought to tally the impact of milk from its production on a farm to the disposal of its carton. In between, the studies try measure such intricacies as the energy used to make the fertilizer to grow feed for the cows, to fuel trucks delivering the milk, and to power refrigerators cooling it in kitchens.”

Click here to read “Hate Calculus? Try Counting Cow Carbon.”

Source: The Wall Street Journal