 In the early 1990s Subak worked as a Senior Analyst at the Stockholm Environment Institute's Boston Center, where she created and updated a country-level greenhouse gas inventory.While working for the United States Environmental Protection Agency in the 1990s Subak published a study comparing the environmental and economic impacts of various beef production practices.Subak has also done research for, and in affiliation with, the European Commission, the United Kingdom’s Environmental Agency, the Swiss’ Federal Office of the Environment, the Swedish Environmental Protection Agency, and the Netherlands Environmental Assessment Agency.