Greenpeace has issued a further report in a campaign to stop the dairy industry using palm kernel expeller imported from Indonesia and Malaysia as stock feed.
Independent scientist Dr Rob Carlton wrote the report that calculates the 1.4 million tonnes of PKE imported into New Zealand during the 2010-11 dairy season could have produced almost 9 million tonnes of carbon emissions.
It says that is equivalent to 12% of New Zealand's total annual greenhouse gas emissions.
Greenpeace has been targeting Fonterra in the campaign to stop New Zealand importing PKE as supplementary feed for dairy cattle.
Palm kernel expeller is a residue left over after extracting oil from the palm seeds.
Greenpeace maintains that the New Zealand dairy industry, as a user of PKE, is contributing to the destruction of tropical rainforests to make way for oil palm plantations.