His reply is good, especially this bit:
> Of course I'm not keen to spend more on plants than I would for an animal product, and one wonders how green something can be when it includes coconut transported via cargo ships and highly refined ingredients.
Further down thread I discuss Oatly and their misleading marketing claims. A healthy amount of skepticism towards magical new solutions is very much in order.
The methane thing is not true and has been debunked as I understand it.
> The most cut and dry benefit to alternatives is far and away animal welfare.
That is... very difficult to debate as it simply depends on where you are getting your milk from. It is certainly possible to produce milk with perfectly happy cows, if that is the main concern could just advocate and insist on that directly.