To work effectively, an IG3IS must integrate high quality observations from multiple and varied platforms, incorporate observation-based information from transport models, and deliver useful information at sub-continental, policy-relevant scales. Existing surface-based networks, emerging networks in developing countries, and new aircraft-based measurements and satellite observations make a difference, but additional observations are critical. In June 2015, the World Meteorological Organization (WMO) Congress agreed that an IG3IS will become an important science-based tool for independent emissions verification and the provision of actionable information for Members on relevant policies. A team of global experts is developing an implementation plan to provide guidance for an IG3IS, ensuring the right steps in the planning and implementation process. An IG3IS is essential to provide the information needed to keep our global temperatures on track. From individual observations to networks to satellites, improved transport models that assimilate observations to constrain the models and improve analysis are essential. Coordinating these efforts with international partners will produce the information needed to responsibly manage atmospheric greenhouse gases both now and in the future. The important steps and plan for implementation of an Integrated Global Greenhouse Gas Information System will be presented.