The irony of having to fill out a captcha before you can play the game is really something

Not just transport but all processes in the supply chain after the food leaves the farm — processing, transport, retail, and packaging — mostly account for a small share of emissions.

This data shows this is the case when we look at individual food products. However, studies also show that this holds true for actual diets; for example, researchers Vilma Sandström and colleagues studied the footprint of diets across the EU. Food transport accounted for only 6% of emissions, whilst dairy, meat, and eggs accounted for 83%.

https://ourworldindata.org/food-choice-vs-eating-local

Factory farming is very much a global problem that's not limited to the US

We estimate that over 90% of farmed animals globally are living in factory farms at present. This includes an estimated 74% of farmed land animals (vertebrates only) and virtually all farmed fish.[1] 

https://www.sentienceinstitute.org/global-animal-farming-estimates

It's not just more people that's caused factory farming. It's increase per capita consumption. The rates of per capita consumption are enormously different. If everyone ate like Americans, we would need 137% of the world's habitable land which includes forests, urban areas, arable and non-arable land, etc. Cutting down every forest wouldn't even be enough

https://ourworldindata.org/grapher/share-of-global-habitable-land-needed-for-agriculture-if-everyone-had-the-diet-of

There are perceptional reasons why it may feel like milk worked better such as it being cooled vs using room temperature water. Or from being the second thing used. Or from various different factors

But the research above suggests it doesn't do as much as people think it does

The infection risks are not the same. Milk has stuff in it that microbes like for growing where water doesn't have nearly all that. Other stuff can enter inside. The eye infection pathway is concerning especially right now when bird flu seems to enter that way and is in large quatities of dairy milk. Not all pasturization methods are certain to actually remove it (i.e flash pasturization might not)

Edit: A minor point to clarify, capsaicin is in pepper spray but not tear gas. They often do get conflated but they are different

Note: When they say animal they're probably using the arguably misleading metric of direct emissions from the creatures themselves. The emissions from animal agriculture include a good chunk from the deforestation and growing of feed for it which would be tied to multiple categories here

Only if they consent :3

(but also probably not great in terms of infection risk either)

That's what people claim, but the research on it suggests it does not do any better for tear gas or pepper spray. Here's one study looking at pepper spray for instance:

In this study, there was no significant difference in pain relief provided by five different treatment regimens. [Water vs milk vs 3 other solutions] Time after exposure appeared to be the best predictor for decrease in pain.

https://pubmed.ncbi.nlm.nih.gov/18924005/

EDIT: Also worth noting that in terms of infection risk, bird flu is now in a large number of dairy samples and it appears like it transmit to humans through the eyes in particular (or at least be one of its transmission pathways).

The workers were most likely exposed to the virus in contaminated milk—by getting it on their hands and then touching their eyes

https://www.scientificamerican.com/article/why-bird-flu-is-causing-eye-infections-in-dairy-workers/

Some types of pasteurization (flash pasteurization) might not fully get rid of all of the virus. So for even just bird flu alone, its likely more of a risk than it probably was in the past

I would think that alcohol on the eyes wouldn't do too many good things to them, however

One of the studied things was using antacids in that pepper spray study and didn't find much benfit for it for pepper spray. There currently doesn't really seem to much that research confirm works any better than any other liquid over the eyes

Don't use dairy milk for tear gas. Comes with infection risks. Water or saline is generally recommended instead. Plant-milks might be ok (but I'm not 100% sure)

That means bacteria can contaminate the milk and potentially cause infection if applied to eyes or skin wounds. Jordt says it’s better to use water or saline solutions to wash out eyes after a tear-gas attack.

https://www.forbes.com/sites/marlamilling/2020/07/21/the-risks-of-using-milk-to-soothe-tear-gassed-eyes-an-expert-says-use-water-instead/

EDIT: accidentally pasted the wrong link earlier somehow, fixed now

Globally, factory farming is dominant

It’s estimated that three-quarters – 74% – of land livestock are factory-farmed. That means that at any given time, around 23 billion animals are on these farms.

https://ourworldindata.org/how-many-animals-are-factory-farmed

You'll find the environmental effects are more so categorical than because of how its produced

How do the distributions between plant-based and meat-based sources compare?

Plant-based protein sources – tofu, beans, peas and nuts – have the lowest carbon footprint. This is certainly true when you compare average emissions. But it’s still true when you compare the extremes: there’s not much overlap in emissions between the worst producers of plant proteins, and the best producers of meat and dairy.

https://ourworldindata.org/less-meat-or-sustainable-meat

Not necessarily. Self citation is different than building on your previous work. You might just seek to use other citations for the relevent concepts

Edit: the 2015 paper this is referencing lists many differing potential reasons for it. Ranging from worrying more about negative feedback for self citation to being more likely to being more critical of their own work

https://journals.sagepub.com/doi/10.1177/2378023117738903