IGAC's parent organizations are the International Geosphere-Biosphere Programme (IGBP) and the international Commission on Atmospheric Chemistry and Global Pollution (iCACGP). IGAC's priorities and activities are guided and, in many cases, implemented by an international volunteer Scientific Steering Committee (SSC). It is then the IGAC International Project Office’s (IPO) responsibility to implement these priorities by working with SSC members and other members of the international atmospheric chemistry community to facilitate and foster their execution. This structure, composed of scientists from all over the world, gives IGAC it's unique ability to truly function without borders.