Until people/animals eat it, or it decomposes. Not saying this like we should ignore the co2 impact from data centers, but biomass is a pretty poor co2 absorber unless its cyano and falls to the ocean floor before decomposing

Goes into cow, comes out as methane. cow dies/meat --> co2. All the fossil fuel transportation for alfalfa to cow to brisket --> co2. Lot more co2 generated than absorbed.