Could we have more clarification on the source of nitrous oxide?

Nitrous oxide is commonly known as ‘laughing gas’ because once in haled it travels in the blood stream to the brain and impacts receptors that trigger happy, carefree, relaxed, and weightless feelings and even stimulate laughing.  It’s an option as a sedative used by dentists to relax patients.  Burning fossil fuels and wood is one source of the increase in atmospheric nitrous oxide, however the main contributor is believed to be the widespread use of nitrogen-based fertilizers. Sewage treatment plants may also be a major source of this gas.

Apart from being created by human activities, nitrous oxide is also released into the atmosphere by natural processes. The Earth’s soil, oceans and atmosphere are all natural sources of nitrous oxide emissions.

Human sources of nitrous oxide are smaller than natural emissions but they upset the balance in the nitrogen cycle that existed before the Industrial Revolution. The quantity of nitrous oxide produced by natural sources is completely offset by natural sinks and has been for thousands of years. Before the influence of humans, nitrous oxide levels were quite steady because of this natural balance.

Soils under natural vegetation are an important source of nitrous oxide, accounting for 60% of all naturally produced emissions. Other natural sources include the oceans (35%) and atmospheric chemical reactions (5%).