Grass-fed beef is carbon neutral
Well-managed grazing can sequester soil carbon, but published estimates offset only a fraction of the emissions, and the effect saturates after a few decades.
Cattle raised on grass and moved through pasture in the way grasslands evolved to be grazed stimulate deep root growth, return dung and urine to the ground, and pull carbon out of the air into the soil, so the methane they emit is balanced by the carbon the pasture locks away. Judged as a whole system rather than by the cow's emissions alone, well-managed grazing can draw down as much carbon as the herd puts out, making grass-fed beef climate neutral and a part of land restoration rather than a cause of warming.
The Food Climate Research Network's assessment found that carbon sequestration under grazing offsets something in the range of a fifth to three-fifths of the emissions from the grazing animals themselves, under favourable management. It is a real effect and worth having.
Two things limit it. Soil carbon accumulation is not indefinite: soils approach a new equilibrium over several decades, after which the sink closes while the methane continues. And grass-fed cattle generally take longer to reach slaughter weight than feedlot cattle, producing more enteric methane per kilogram of meat. Grazing systems have genuine advantages in biodiversity and on land unsuitable for crops, but carbon neutrality is not among them.
Presenting only the evidence that supports a conclusion while leaving out evidence that tells against it.
How it applies here: Counts the sequestration side of the ledger and not the methane, and uses figures from the best-performing systems rather than typical ones.
Drawing a general conclusion from a sample too small or too unrepresentative to support it.
How it applies here: Extrapolates from a small number of well-managed operations to grass-fed beef as a category, when most production does not meet those management conditions.