This document should be of interest to a broad audience interested in reducing greenhouse gas (GHG) emissions to the atmosphere. It was developed for regulatory organizations, project developers, and national and state policymakers to increase awareness of existing and developing monitoring, verification, and accounting (MVA) techniques. Carbon dioxide (CO2) sinks are a natural part of the carbon cycle; however, natural terrestrial sinks are not sufficient to absorb all the CO2 emitted to the atmosphere each year. Due to present concerns about global climate change related to GHG emissions, efforts are underway to assess CO2 sinks, both terrestrial and geologic, as a form of carbon management to offset emissions from fossil fuel combustion and other.