well, we know that animal agriculture results in deforestation. so it's not so simple. one would need to calculate both the carbon output of animal agriculture

well, we know that animal agriculture results in deforestation. so it's not so simple. one would need to calculate both the carbon output of animal agriculture and - crucially - the carbon that will /permanently/ not be captured via loss of land that serves as a carbon sink (Amazon rain forest is the big one) that results as demand for additional animal agriculture increases.