In this contribution I describe two applications of Fourier transform infrared spectroscopy to the monitoring of atmospheric compounds. First, I present an overview of IR solar absorption spectroscopy of the atmosphere: a bit of history, environmental relevance, and its use as a tool to determine the composition of the atmosphere. I then report FTIR solar spectroscopy measurements carried out at ground level at National Center for Atmospheric Reserach and on airplanes employing a spectrometer of 0.06 cm-1 resolution. Sample atmospheric spectra and fitting examples are presented for key species relevant to stratospheric chemistry and global change: ozone (O3) a chlorofluorocarbon (CF2Cl2), a greenhouse gas (N2O), HCl, NO and HNO3. Second, I briefly describe urban air pollution measurements at an intersection with heavy traffic in Tucson, Arizona. Two FTIR spectrometers of 1 cm-1 resolution were employed to carry out long-path open-path measurements of the CO/CO2 ratio and SF6. Two FEAT and two LPUV instruments were employed for ancillary measurements of CO, CO2, NO, CO/CO2 ratios obtained by FEAT exhaust emission and FTIR ambient air measurements are reported. The two-week campaign was supported by the US DOT and EPA.