The ecological disaster associated with meat has been known about for a long time. This news report from 2006 by the FAO (Food and Agriculture Organization of the United Nations) describes how livestock production is responsible for 18% of the greenhouse gas carbon dioxide, 37% of methane (which is 23 times as strong as CO2 as a green house gas) and 64% of ammonia (which causes acid rain), and is the leading cause of wide-scale land degradation “with about 20 percent of pastures considered as degraded through overgrazing, compaction and erosion”, contributes to water pollution, water euthropication and the degeneration of coral reefs, the demand for feed crops “also contribute to biodiversity loss; 15 out of 24 important ecosystem services are assessed as in decline, with livestock identified as a culprit”.
Link to the full story on FAO website: