There are other, cheaper methods of obtaining protein. Some of which are locally available. In Africa, for example, insects are used as local source of protein. They have a low Co2 footprint for a variety of reasons:
* Because a lack of transportation (locally available). Especially when compared to trademark protected cheeses such as Gorgonzola.
* Barely any land is used and it can be stacked, allowing more space for other land usage (generally that could be forests, or at least not adding to deforestation).
* No methane enters the air which directly affects Co2 emissions (which cows, generally the main animal used for cheese, do produce a lot).
Compare insects and cheese to avocados: for Europeans avocados are not locally grown, and the deforestation is a "far from my bed" show.
It's all about branding.