The human-caused (anthropogenic) rate of species extinction is already 1,000 times more rapid than the ‘natural’ rate of extinction typical of Earth’s long-term history, with the result that we are currently living through one of the very few mass extinctions to date. It is clear that climate change represents the greatest threat to life on Earth for many millennia.

Given the urgency with which we must reduce the size of our collective ecological footprint, it is remarkable that so little attention has been afforded to livestock production. The inconvenient truth is that the emissions resulting from clearing land to graze livestock and grow feed, from the livestock themselves, and from processing and transporting livestock products, are greater than those resulting from any other sector. These factors are explored, as are the profound impacts of climate change on global food security.

Strategies for mitigating the environmental damage created by livestock production are reviewed. It is clear that replacing livestock products with alternatives would be the best strategy for reversing climate change, and would have far more rapid effects on green house gas emissions and their atmospheric concentrations, than actions to replace fossil fuels with renewable energy sources.