A 2018 study by the University of Oxford argues that diets excluding animal products (including milk) have a transformative potential in terms of land use (76% reduction), food’s GHG emissions (49% reduction), acidification (50% reduction), eutrophication (49% reduction) and scarcity-weighted freshwater withdrawals (19% reduction). This is mainly due to the fact that emissions from the production of feed for animals exceed emissions of vegetable protein farming; deforestation is necessary for animal feed (soy, maize) and pasture for grazing. Animal manure and the process of enteric fermentation also contribute to additional emissions.
The environmental impact of dairy alternatives varies depending on the ingredients used as replacements. Soya has gained criticism since it has encouraged deforestation in South America, particularly in the Amazon. However, only 6% of soya is consumed by humans, with the rest used mainly as animal feed. In this case, it’s important to consider consuming products that use organic soya or soya grown outside of South America. Almonds have also recently been criticised for their fertiliser, pesticide and water-intensive nature, with 4.5 litres of almond milk requiring approximately 4,182 litres of water. Considering 80% of almonds are grown in drought-prone California, the impact on water availability is considerable. Furthermore, almonds require bees to support pollination, but the use of pesticides has led to the suffering of 15% to 25% of exposed beehives. Rice is also water intensive, with 4.5 litres of rice milk requiring 554.6 litres of water. Rice paddies contribute to around 10% of agricultural emissions and their added transport emissions are unfavourable. Coconuts do not require pesticides, however, there are issues with monocropping which negatively affects biodiversity, and transportation emissions will always be significant since the crop does not grow well in Europe. Oat milk has a lower environmental impact as it can be grown in cooler climates and as such, is not associated with high deforestation rates in the global South. However, oats which are mass produced and grown in monocultures - a common occurrence - are sprayed with Roundup pesticides containing glyphosate, a carcinogen. Oat milks can be certified glyphosate free or be indirectly so by being certified organic.
The social implications of dairy alternatives are also dependent on the type of ingredients used. Possibly the most ethically at risk crops are coconuts. This is because coconut farmers are some of the poorest farmers in countries like Indonesia and the Philippines, and given these are farmed on small plots of land, prices are unfavourable. Furthermore, without ethical schemes in place for this less popular commodity, it's difficult for farmers to ensure premiums above market price.