Climate change refers to sustained variations in the Earth’s climate. These changes are credited to both anthropogenic and natural origins. These natural drivers include internal forcing mechanisms such as albedo (measurement of light reflection by the Earth from the sun), volcanism, ocean circulation, and atmospheric composition. They also include external forcing mechanisms such as the distance of the Earth from the sun, orbital variations, solar energy, sunspots, and oscillation of the Earth. Human drivers of climate change include the burning of fossil fuels, pollution from power plants, intensive agriculture, deforestation, desertification, livestock management, and overfishing.

Of these human-caused warming effects, 31% are likely due to the global production and distribution of food (Lappé, 2010, p. xv). Although the Earth’s biosphere has faced natural evolution since the ...