Global monitoring of greenhouse gases and carbon across the coupled earth system would enhance the quality of greenhouse gas emission and removal information available to inventory compilers, auditors, businesses and policy makers. A robust monitoring system would combine direct measurements
of the atmosphere, land and oceans, earth system models, inventories and other information to accurately estimate greenhouse gas and carbon stocks and fluxes, towards increasing the overall confidence in reports of mitigation actions and assessments of the ultimate efficacy of those actions.
Deploying a monitoring system that offers sustained, accurate, transparent and relevant information represents a challenge and opportunity to a broad community spanning earth science, greenhouse gas accounting and public policy. An introduction to some of the scientific and technical infrastructure
issues associated with monitoring systems is offered here to encourage future treatment of these topics by other contributors to this journal.