Rieker's group develops field-deployable dual-frequency-comb laser absorption spectroscopy for precise, broadband, open-path measurement of greenhouse gases, combustion, and environmental/energy systems, translating frequency-comb precision into real-world trace-gas sensing. For context, this complements the established paradigm of NV-diamond ensemble magnetometry (Hahn-echo/DEER, nanoscale NMR, T1 relaxometry) operating near pT/√Hz sensitivity.