Look at it another way - do we REALLY need that much meat production? Probably not. Vegans have been living just fine this whole tome, and meat is very resource intensive to produce anyway, so one could argue you'd get even more food from stopping.

Is it causing massive issues even aside from the suffering of animals? Yeah, agriculture plays quite a significant part in CO2 emissions. Not to mention the polluting of rivers.

Also, I don't really see your point of 'they don't want to have a discussion'. You're literally having a discussion with them right now.