Nearly two decades of NASA technology investment in lidar systems and two-micron transmitters has resulted in a new capability for remotely measuring the carbon dioxide (CO2) levels in Earth’s atmosphere. NASA has developed an Integrated Path Differential Absorption (IPDA) Lidar that incorporates highenergy, double-pulse lasers with high repetition rates. The compact lidar instrument aims to provide accurate, highresolution atmospheric CO2 column measurements from an airborne platform. The laser pulses can be tuned and locked near the 2.05 micron wavelength, an ideal spectral region for CO2 sensing. Separated by 150 microseconds, the first pulse is tuned to a high CO2 absorption wavelength and the second pulse to a low absorption wavelength. By aiming the pulses at a hard target, or Earth, the difference between the return signals correlates to the average amount of CO2 in the column between the instrument and the target.