Community greenhouse gas inventories regularly include GHG emissions from local transportation activities, but emissions associated specifically with ride-hailing have not previously been quantified and reported separately. This report reviews the emerging evidence that ride- hailing is quantitatively significant as an emissions source in major urban areas, that it differs from the use of the automobile generally, and that it has impacts on other transportation modes. In sum, these factors suggest that ride-hailing warrants consideration as a distinct transportation mode and emissions source. The report then builds on existing protocols and methods to detail three separate approaches to quantifying GHG emissions from ride-hailing. The approaches depend to varying degrees on data that may or may not be available in a specific community. The closing discussion suggests policy and methodology directions to improve the future insight into the carbon footprint of this emerging mode.