text: Laser spectroscopy can be used to measure isotope enrichments of gases in the environment. Laser spectroscopy takes advantage of the different vibrational frequencies of isotopologues which cause them to absorb different wavelengths of light. Transmission of light through the gaseous sample at a controlled temperature can be quantitatively converted into a statement about isotopic composition. For N2O, these measurements can determine the position specific isotope enrichments of (N. These measurements are fast and can reach relatively good precision (1-10 per mille). It is used to characterize environmental gas fluxes, and effects on these fluxes. This method is limited to measurement and characterization of gases.