Maintaining an adequate global supply of qualified geoscientists is a major challenge facing the profession. With global population expected to exceed 9 billion by midcentury, the demand for geoscience expertise is expected to dramatically increase if we are to provide to society the resource base, environmental quality, and resiliency to natural hazards that is required to meet future global demands. The American Geoscience Institute (AGI) has for the past 50 years tracked the supply of geoscientists and their various areas of specialty for the US. However, this is only part of the necessary workforce analysis, the demand side must also be determined. For the past several years, AGI has worked to acquire estimates for workforce demand in the United States. The analysis suggests that by 2021 there will be between 145,000 to 202,000 unfilled jobs in the US. This demand can be partially filled with an increase in graduates (which is occurring at an insufficient pace in the US to meet full demand), increased migration of geoscientists internationally to the US (a challenge since demands are increasing globally), and more career placement of bachelor degree recipients. To understand the global workforce dynamic, it is critical that accurate estimates of global geoscience supply, demand and retirement be available. Although, AGI has focused on the US situation, it has developed international collaborations to acquire workforce data. Among the organizations that have contributed are UNESCO, the International Union of Geological Sciences (IUGS), the Young Earth-Scientists Network, and the Geological Society of Africa. Among the areas of international collaboration, the IUGS Task Group on Global Geoscience Workforce enables the IUGS to take a leadership role in raising the quality of understanding of workforce across the world. During the course of the taskforce's efforts, several key understandings have emerged. First, the general supply of geoscientists is quantifiable with the caveat that the definition of what constitutes a geoscientist does vary from country to country and region to region. Second, the flow of geoscience talent is both complex and dynamic as there are distinct sources and sinks for talent, but as economic conditions and resource demands vary, the migratory paths appear to change rapidly. Finally, the issue of a nationality of a geoscientist is a much more complex concept than it might appear. With the educational centers not always mapping to where demand is, coupled with a truly global geoscience economic enterprise, tracking geoscientists is problematic. As global demand for geoscience continues, measuring the supply and demand globally will become even more critical for geoscientists, their employers, their schools, and their societies to understand to support a healthy profession. However, in the data collection efforts, specific gaps of data are persistent, especially in Latin America where efforts have never been able to be carried beyond initial consultations, and concerns about reported numbers from less open countries expressed by ex-pats regarding what has been reported by those institutions. A truly global and open collaboration is key for the health of the profession in the 21st Century.