Replacing rose-tinted spectacles with a high-powered microscope: The historical versus modern carbon footprint of animal agriculture

As the global population increases, more animal protein needs to be produced using fewer resources (land, water, and energy) and with a smaller carbon footprint. Improved productivity has considerably reduced the carbon footprint of dairy and beef production over the past century. Extensive systems intuitively appear to be more environmentally friendly, yet scientific analysis demonstrates that intensive systems reduce resource use, waste output, and greenhouse gas emissions per unit of food. As livestock production systems continue to make productivity gains, sustainability should be assessed on the basis of environmental, economic, and social issues.