Advanced Global Atmospheric Gases Experiment (AGAGE), and its predecessors (the Atmospheric Life Experiment, ALE, and the Global Atmospheric Gases Experiment, GAGE) have been measuring the composition of the global atmosphere continuously since 1978. 

The AGAGE is distinguished by its capability to measure over the globe at high frequency almost all of the important gases species in the Montreal Protocol (e.g. CFCs and HCFCs)  to protect the ozone layer and almost all of the significant non-CO2 gases in the Kyoto Protocol (e.g. HFCs, methane, and nitrous oxide) to mitigate climate change.

AGAGE is part of the powerful global observing system that is measuring halocarbons, including bromocarbons, in the Earth's atmosphere. The original ALE/GAGE/AGAGE stations (Mace Head, Trinidad Head, Ragged Point, Cape Matalula, and Cape Grim) occupy coastal sites around the world chosen to provide accurate measurements of trace gases whose lifetimes are long compared to global atmospheric circulation times. Two stations in Europe (Zeppelin, Jungfraujoch) and two in East Asia (Shangdianzi and Gosan) have joined the AGAGE network in recent years by using the same instrument and calibration scales. 

AGAGE also collaborates with stations at Hateruma Island operated by the Japanese National Institute for Environmental Studies (NIES), and Monte Cimone managed by University of Urbino, Italy.