Beef is single-handedly the biggest culprit, with researchers from Bard College, the Weizmann Institute of Science, and Yale University finding that it uses 28 times more land per calorie consumed, and 11 times more water, than other livestock categories. The production of poultry, pork, milk, and cheese falls somewhere in the middle, while the lowest impact comes from — you guessed it — food sources like nuts, beans, fish, and eggs. To combat the dependence on beef when it comes to the Western diet, the key is to get creative. In November, The Guardian published an article titled " The Seven Megatrends That Could Beat Global Warming ," voting meat and dairy alternative products as number one. Plant-based meat, a growing category of high-tech, healthy vegan substitutes that taste, smell, and even bleed like the real thing, have a tiny environmental footprint. The excitement around the niche industry recently led entrepreneur Richard Branson to say he believes that, "In 30 years or so, we will no longer need to kill any animals and that all meat will either be lab- or plant-based, taste the same, and also be much healthier for everyone."