After a development phase of more than four years, a new multi-wavelength LIDAR system for climate research has successfully been tested onboard the HALO research aircraft for the first time. Its aim is the simultaneous remote sensing of the greenhouse gases CO2 and CH4 in the atmosphere, responsible for a large part of anthropogenic global warming and playing a key role in climate projections. The setup of this highly complex system, funded by BMBF over three years, occurred under close collaboration with the Fraunhofer Institute for Laser Technology and the company OHB (formerly Kayser-Threde).