Synthesis of Global Soil‐Emitted N2O Isotopic Signatures: Geoclimatic Patterns and Influential Factors

Nitrous oxide (N2O) is a powerful greenhouse gas that also harms our ozone layer. It is mainly produced by microbes in soil through processes influenced by both natural conditions and human activities. This study collected field data from over 40 publications to create a global picture of the isotopic signatures of soil‐emitted N2O. By measuring variations in N2O isotopes, we can trace how and whereN2O is produced. Here, we used a mathematical model to separate and quantify different microbial processes that generate N2O across different soils. Our analysis showed that croplands, which receive synthetic fertilizers, have the most varied nitrogen isotope values. This suggests that human activities strongly affect N2O production in these areas. In contrast, forests and grasslands have more narrow ranges of isotopic signals. The model result indicated that denitrification is the main process producing N2O across most ecosystems. We also found that environmental factors, such as soil pH and moisture, significantly influence these isotopic signatures.Understanding the detailed isotopic patterns of N2O emissions helps improve global models of nitrogen cycling and climate change. These insights are essential for developing targeted strategies to reduce N2O emissions.