Limiting ruminant meat consumption to 52 calories per person per day by 2050—about 1.5 hamburgers per week—would reduce the GHG mitigation gap by half and nearly close the land gap. In North America this would require reducing current beef and lamb consumption by nearly half. Actions to take include improving the marketing of plant-based foods, improving meat substitutes and implementing policies that favor consumption of plant-based foods.
Source: How to Sustainably Feed 10 Billion People by 2050, in 21 Charts | World Resources Institute