This. There needs to be a pyramid in top of the food pyramid. Beef is not bad per se, it just shouldn't be your weekly meat.
From an environmental point of view, there’s a linear relationship between your consumption of beef and environmental impact. There is no amount of beef that is good for the environment.
From a health point of view, it’s debated, however there are more studies that show red/processed meats having negative health effects than neutral or positive effects. Of course, you can cherry pick the studies that align with your beliefs, but the prevailing data, evidence, and research show beef actually _is_ bad per se.
Note: there is no nutrient (that we know of) that you can only get from beef and no other food source. So it isn’t necessary to include it in your diet.
https://www.health.harvard.edu/staying-healthy/whats-the-bee...
That's a tautology. In that strict sense, there's no amount of you that's good for the environment, either. Unless we all commit suicide, we have to accept the fact that our behavior changes the environment. So, yes, quantities matter a lot.
Industrial cattle fed corn is an entirely different story and should almost certainly be counted as a different category as far as climate impact is concerned.
CH4 is another issue, but again, unless I'm missing something, total CH4 from cattle in the atmosphere should be proportional to the average number of heads alive. If we don't increase herd size, it won't go up — unlike CO2 from fossil fuel use.
With a low enough amount of cows bred in more traditional ways, there would be a cycle where an equivalent amount of carbon would be captured by plants vs what is excreted by the cow. That's why animal farming has not been a source of net CO2 for the thousands of years that we have been doing it before industrial times.
However, going back to historic sustainable levels means a drastic reduction in consumption of meat and dairy - probably a few times per year or something like that. Putting all livestock together, it would mean people could eat meat maybe once a month. Eggs and dairy may be a little more common, as those are collected throughout the life of the animal.