Across the globe, human beings are developing a strong taste for meat. A study published this week in the Proceedings of the National Academy of Sciences finds that rapidly industrializing countries, such as China and India, are adding much more animal flesh to their menus, negating decreases in carnivorous habits in other nations. Taking into account that raising livestock contributes 18% to greenhouse gasses, a growing meat-eating population is a signal of bad times to come for our dear planet.
Led by Sylvain Bonhommeau from the French Research Institute for Exploitation of the Sea in Sète, researchers calculated the trophic levels for a variety of organisms. Plants and algae that make their own food were on the first level, animals such as deer that eat these plants inhabit the second, organisms that eat herbivores like foxes occupy the third slot, fish that eat other fish like cod are in the fourth level, and top predators such as orcas take the highest seats. The study looked at data spanning from 1971 to 2009 and concentrated on 102 types of food. For 2009, the researchers placed humans at a level of 2.2, putting them in the company of omnivores, but closer to herbivores than top predators.
Over a 50 year period, the global median trophic level increased three percent. While this may not seem like a significant figure, the number translates into an exponential increase in resource diversion to sustain animals for the dinner table. From fish farms to ranches, feedstock must be raised to nourish the animals, water found to quench their thirst, land partitioned to support their movement and take care of their waste, and medicines administered to ward off disease. If you throw in their contributions to greenhouse gas emissions, eating a hamburger becomes much more dangerous than getting a bloated waistline.
Images via Wikicommons user Иван and Sylvain Bonhommeau