Livestock for New Climates: Neolithic Sheep, Colonial Pigs, and GM Cows

Cows are a major source of greenhouse gases, a fact that creates a dilemma for those who value both hamburgers and a habitable planet. Thankfully, animal scientists are hard at work inventing genetically modified cows that belch less methane.

You might consider this a twist on an age-old tale. Today, livestock genetics are being modified so the animals don’t harm the climate, whereas traditionally those genetics were modified so that the climate didn’t harm the animals.

This presentation is a brisk march through 10,000 years of interactions between climate and livestock, from initial domestication in the Near East and Asia, to the transport of animals to varied climates around the globe, to the rise of scientific breeding and genetic modification.

Considering Earth’s vast biodiversity, human farmers have relied on a tiny number of animals: primarily cows, pigs, sheep, goats, and chickens. After initial domestication in the Near East and in Asia, this limited arsenal of animals quickly spread around the world. In this process, evolutionary pressures and deliberate breeding practices created livestock that varied in heat tolerance, UV protection, pathogen resistance, food tolerance, reproductive rates, and more. Consider the differences between Scottish Highland cattle and the Zebu of India, between the low-slung pigs of Southeast Asia and the leggy forest hogs of medieval Europe, between the heat-tolerant Rambouillet sheep of the American West and the Arctic-adapted Icelandic breed. Each climatic niche has been filled with an appropriately bred domestic beast.

Humans went to great lengths to transport animals around the world and to help them adjust to local environmental conditions. They did so because animals provided crucial supplies of food and fiber, as well as a reliable way to accumulate riches. Humans who successfully bred and raised livestock accrued power and wealth, a truth that held both within and across societies: the wealthiest nations are also those who produced and consumed the most meat. As global living standards have risen, so has meat production, and with it the attendant climate implications—cows and sheep spewing methane, carbon-storing forests felled to grow maize and soy, petroleum converted to fertilizer to nourish these feed crops. Unsurprisingly, the societies suffering the most from climate change contributed little to this problem. Genetically modified cattle may someday help mitigate harmful emissions, producing a source of guilt-free meat. But who will be invited to the feast?