Explain how changes in agriculture may have contributed to global temperature changes.

Modern agriculture contributes to an increase in global temperatures through the release of greenhouse gases into the atmosphere. Greenhouse gases (such as carbon dioxide and methane) contribute to the greenhouse effect by trapping heat emitted from the earth’s surface, so less heat is emitted out of the atmosphere.
Producing food uses fossil fuels in the production of fertiliser and pesticides, and in transportation. Burning fossil fuels releases carbon dioxide into the atmosphere. Cutting down trees (deforestation) for farmland also releases carbon dioxide into the air and reduces the amount of carbon stored. Increases in meat (especially cattle), dairy and rice production creates more methane.