Humanity is producing more and more climate-damaging nitrous oxide – the third most important greenhouse gas after carbon dioxide and methane, according to a comprehensive analysis published in the United States. In the four decades since 1980, nitrous oxide emissions caused by humans have increased by around 40%, the Global Carbon Project research network led by Boston College in the north-east US state of Massachusetts showed. The values were particularly high in the most recently analysed years 2020 and 2021. Doctors use nitrous oxide, also known as nitrogen monoxide or N2O, as an anaesthet…