In the cocktail bar setting it would not be normal to choose between beef or peas for a cocktail ingredient, but still there are some facts to learn from this story on Vox.com called "How to reduce your food’s carbon footprint, in 2 charts."

Visit the link to see (and blow up) a chart that compares for many foods the land use, transport, packaging, and other factors of foods' carbon impact. It's very interesting. 

The story's subtitle declares that transportation costs of shipping foods to consumers is not a significant factor compared to whether those foods are animal-based (a lot of CO2 emissions from land use, farming, animal feed) versus plant-based. "The distance our food travels to get to us actually accounts for less than 10 percent of most food products’ carbon footprint."

But in the bar setting, really the only animal products we're worried about are eggs used to make frothy cocktails, and maybe a bit of milk. If we compared one plant vs another this chart may reveal more useful differences compared to each other rather than vs meat. But still we can learn from it. 

Some observations:

• Chocolate and Coffee have a larger carbon impact than pork, poultry, and fish! 
• Eggs have a larger carbon impact than milk does, so if you were deciding between making cocktails frothy with egg whites vs milk-washed spirits, go with milk.
• However, nut milks are better than dairy milk in general. (This chart shows nuts having a negative carbon impact overall; I am not sure if they take water use into account but it does not appear so.)
• Soy milk is less than 1/3 the carbon impact of cow milk.
• "0.16 percent of food is air-freighted, while the vast majority travels by boat (including those beloved avocados)"
• "It can be hard to know which products in your grocery store are air-freighted, since they’re almost never labeled as such. But a good rule of thumb is to avoid fresh fruits and vegetables that have a short shelf-life and that come from far away (check the label for their country of origin). Berries, green beans, and asparagus are examples of foods that are often air-freighted. Locally sourced berries, green beans, and asparagus, though, have a low carbon footprint."