Emissions of the third most prevalent climate-damaging greenhouse gas, nitrous oxide (N20), have surged by some 40% in the past 40 years, according to a new study. The analysis carried out by the Global Project research network, led by Boston College in the US, found that the levels were particularly high in the most recently analysed years of 2020 and 2021. The gas is commonly used in medical settings as an anaesthetic dubbed laughing gas. However, much larger quantities of emissions are produced unintentionally, such as during the fertilization of fields or the burning of fossil fuels, and c…