Investigating the Carbon Footprint of Cattle Grazing the Lac du Bois Grasslands of British Columbia

Abstract

Greenhouse gas emissions from cattle have been increasingly recognized as an important anthropogenic source. We investigated the impact of cattle ranching on these emissions in British Columbia in order to determine the overall carbon footprint. The grazing activity within the Lac du Bois grasslands of British Columbia was examined, with emphasis on identifying point sources and removals of greenhouse gas emissions from cattle ranching. Enteric methane emissions were empirically measured at two elevation gradients in the spring and fall of 2010. Cattle emitted on average 370 L CH4 per day; these measurements on native grasslands are comparable to work on tame pastures. A life cycle analysis was conducted with a validated HOLOS model based on empirical measurements. The following grassland improvement strategies were evaluated: reducing stocking density; and reseeding/interseeding grass and legumes with and without synthetic fertilizer additions. Reseeding was the most effective at reducing the carbon footprint of cattle ranching on the Lac du Bois grasslands. Reseeding initiatives could theoretically result in soil carbon sequestration rates of 2.12 Mg CO2 equivalent per hectare. A combination of reductions and removals should be implemented in the future to reduce the overall carbon footprint of cattle ranching in British Columbia.