Crutzen then noted that increasing use of fertilizers might have led to an increase in nitrous oxide emissions over the natural background, which would in turn result in an increase in the amount of NO in the stratosphere.
Crutzen kemudian mencatat bahwa peningkatan penggunaan pupuk mungkin telah menyebabkan peningkatan emisi oksida nitrat di atas latar belakang alami, yang pada gilirannya akan menghasilkan peningkatan jumlah NO di stratosfer.