The need for a quantitative assessment of animal welfare trade-offs in climate change mitigation scenarios

The global livestock sector accounts for a substantial share of anthropogenic greenhouse gas (GHG) emissions and is one of the most important causes of climate change. Methane (CH4) and nitrous oxide (N2O) are GHGs produced through enteric fermentation and manure volatilization that have 25- and 298-fold global warming potential, respectively, in CO2 equivalents. Considering the relevance of the livestock sector for GHG emissions, it is now playing a major role in the mitigation effort. Recent literature highlights different strategies to reduce GHG emissions. The main direct strategies proposed are enteric CH4 mitigation practices for ruminants and manure mitigation practices for both ruminant and monogastric species. In light of further changes in livestock systems to tackle climate change, it is important to identify and describe potential side effects. Particular attention should be given to the risks of any unintended impact on the animals’ health and welfare.