What is the effect of agriculture on greenhouse gas emissions?

Agriculture significantly contributes to greenhouse gas emissions, primarily through methane and nitrous oxide production.

Agriculture is a major source of two potent greenhouse gases - methane and nitrous oxide. Methane is produced by livestock during digestion due to the process of enteric fermentation and is also released during the handling of animal manure. In fact, livestock farming is responsible for about 44% of all global methane emissions.

Nitrous oxide is released from soils after the application of synthetic fertilisers and animal manure, which are high in nitrogen. The bacteria in the soil break down this nitrogen, releasing nitrous oxide as a by-product. This gas is approximately 300 times more potent as a greenhouse gas than carbon dioxide. Agriculture is estimated to be responsible for about 80% of all nitrous oxide emissions globally.

In addition to these, agriculture also indirectly contributes to carbon dioxide emissions. This is through the use of fossil fuels in agricultural machinery, and through the process of deforestation to create more agricultural land. When forests are cleared, the carbon stored in the trees is released into the atmosphere, contributing to increased levels of carbon dioxide.

Furthermore, rice cultivation is another significant source of methane emissions. When rice fields are flooded, the anaerobic conditions promote the growth of microbes that produce methane.

Overall, the Food and Agriculture Organisation estimates that agriculture, forestry and other land use activities accounted for approximately 24% of all greenhouse gas emissions in 2016. This makes the agricultural sector a key area for potential reductions in greenhouse gas emissions.