1 Greenhouse gas emissions from agriculture

1.1 Greenhouse gases

The relationship between agriculture and climate change is a complex one.

Agriculture is part of a wider ‘food system’, which includes the transport and distribution of food, its processing and cooking and dealing with food-related waste resources. Our food system not only produces climate-changing gases; it in turn is influenced by them.

Agriculture is just one part of the food system that generates the greenhouse gas emissions that contribute to climate change.

Agriculture produces three main types of gas emission that cause climate change: methane, nitrous oxide and carbon dioxide.

• Methane has around 20 times the greenhouse effect of carbon dioxide and is released by natural livestock emissions and manure.

• Nitrous oxide has around 310 times the greenhouse effect of carbon dioxide and is released from the production and use of fertiliser (including from muck spreading) and soil disturbance.

• Carbon dioxide is released by burning fossil fuels (e.g. fuel in tractors, farm vehicles, machinery and the production of agricultural chemicals), changes in land use and land management.

It is estimated that food-related activity (not just agriculture but all parts of the food chain) could contribute up to 32 per cent of global greenhouse gas emissions.