The total mass of all humans and domestic animals increased by nearly 3.5 times from 1900 through the early 21st century. This increase is thought to be the result of more easily accessible sources of food. The population of wild animals did not follow the same trend as domestic animals — it actually decreased by an estimated 25% from 1960 through the early 2000s. For example, in 1900, the total mass of all humans was four times more than the world’s elephants, and by the year 2000, humans accounted for 200 times more mass than elephants. This was because of an increase in the human population and a decrease in the elephant population.
More about humans and animals:
- The world’s cattle population weighs 16 times more than the combined weight of the world’s wild mammals.
- About 93 pounds (42 kg) of meat were produced for every person in the world in 2007, and meat production was projected to double by 2050.
- Chickens were the animal that had the fastest growth rate during the late 20th century and early 21st century, with an increase from 3.9 billion chickens in 1961 to 19 billion in 2011.
