The Biggest Contributor To Climate Change Isn’t What You Think

“And he gave it for his opinion, that whosoever could make two ears of corn or two blades of grass to grow upon a spot of ground where only one grew before, would deserve better of mankind, and do more essential service to his country, than the whole race of politicians put together.” —Jonathan Swift, Gulliver’s Travels

In A Nutshell

The industrialization of many Western nations coincided with an increased use of fossil fuels, resulting in higher-than-normal global levels of carbon dioxide. This excess carbon dioxide coincides with a very rapid increase in the Earth’s temperature. Many people have paired this unnatural global warming with “trains, planes, and automobiles,” but the largest contributor to climate change is actually agriculture. Deforestation, fertilization, and crop cultivation done for farming has contributed to about one-fourth of all excess CO2 emissions.

The Whole Bushel

Agriculture is humanity’s way of supporting an ever-increasing population. Because of sedentary farming, humans were able to increase to a population of seven billion: We are the most successful mammals to have ever existed.

Ironically, however, the very thing that allowed us to grow exponentially is now the biggest contributor to a harmful planet-wide problem. Agriculture is the largest overall contributor to man-made climate change, a trend in which the increased global temperature of the Earth corresponds with an increased amount of carbon dioxide (and other gases) in the Earth’s atmosphere.

If there were no carbon dioxide in the atmosphere, the planet would be ice. The Earth has natural methods for dealing with carbon dioxide, including ocean absorption, plant consumption, and chemical reflection. However, in the 1800s, countries like the United Kingdom and United States began to burn fossil fuels (think gasoline) and clear out huge swaths of forests to make way for industrialization. These activities forced more carbon dioxide into the Earth’s atmosphere than it was equipped to handle. As a result, the Earth (which actually goes through warming and cooling periods naturally) began to warm rapidly to relatively high temperatures.

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Many current campaigns to reduce carbon emissions focus on automobiles that use gasoline, and therefore emit carbon dioxide. However, the largest contributor to current climate change is actually agriculture. About 25 percent of all carbon dioxide emissions are related to agriculture. Commercialized agriculture can support larger populations, but it also requires bigger areas of land, so is a major factor in deforestation (fewer large plants to act as carbon sinks). Fossil fuel–based fertilizers in farming (and the burning of biomass) also contribute to carbon dioxide emissions.

Carbon dioxide is not the only gas with global warming potential, but its concentration in the atmosphere is much higher than others. But rice cultivation and cattle flatulence (seriously) are a large source of methane emissions, while other fertilizations are major sources of nitrous oxide.

If agriculture has such a huge effect on global warming, what effect will global warming have on agriculture? Many environmental systems may change, making them less hospitable to farming. However, increased carbon dioxide may result in better crop productivity in the areas that are arable.

Show Me The Proof

Climate Institute: Agriculture and Climate Change
TED: Jonathan Foley: The other inconvenient truth