CDIAC at AppState

Climate change is occurring as a result of changes in the chemistry of the Earth’s atmosphere. These changes are being driven primarily by the release of carbon dioxide (CO2) from fossil fuel combustion and other industrial processes. Monitoring fossil fuel CO2 emissions is essential as the need and prospects for reducing emissions become critical and the obligation to monitor the success of mitigation actions looms. These inventories are powerful tools as nations, corporations, and individuals grapple with appropriate reduction targets, and as verification that these parties are meeting their objectives.

A consistent time series of data on CO2 emissions from fossil fuel use and cement manufacture was for many years generated and updated annually by the Carbon Dioxide Information and Analysis Center (CDIAC) at the U.S. Department of Energy’s (DOE) Oak Ridge National Laboratory (ORNL). The CDIAC annual inventories began in 1984 and were continued through 2017. The CDIAC emissions data set extended from the beginning of the industrial era (1751) to essentially the present.  There is a data lag of 2 to 3 years due to the time needed for collecting and processing the primary data. The DOE ceased support for CDIAC in 2017. The last release supported by the DOE included emission estimates for the year 2014. 

The CDIAC fossil fuel CO2 emissions time series was restored at Appalachian State University in 2019 with independent support from Appalachian State University’s College of Arts and Sciences. The dataset is now being referred to as CDIAC-FF with the intention to acknowledge both the transition to Appalachian State University and the scientific continuity with the dataset founded at Oak Ridge National Laboratory.  Emissions of CO2 from fossil fuel consumption are not measured directly but are generally estimated from data on the quantity and chemistry of fossil fuels that are consumed. Data concerning production, processing, trade, and consumption of fossil fuels are assembled annually by the United Nations (UN) Statistics Division and are the foundation of the CDIAC-FF estimates of CO2 emissions from fossil-fuel combustion.  Data from the United States Geological Survey are the foundation the CDIAC-FF estimates of emissions from calcining limestone to manufacture cement.  Transition to Appalachian State includes two substantive refinements in the calculation of emissions estimates:  1) the treatment of annual changes in stocks on hand of fossil fuels and 2) the recognition of changes over time and place in the chemistry of cements. 

The historic emissions data from CDIAC at ORNL are stored at the DOE’s Environmental Systems Science Data Infrastructure for a Virtual Ecosystem (ESS-DIVE) data repository at the Lawrence Berkeley National Laboratory.  Data products for the most recent release and methodology from our team at Appalachian State are available in the links below. For previously released versions of CDIAC-FF, please refer to here.

Permission to Use the Data

If you wish to use a diagram, image, graph, table, or other materials from this website and are concerned with obtaining permission and possible copyright restrictions, there should be no concerns. All of the reports, graphics, data, and other information on this website are freely and publicly available without copyright restrictions. However, as a professional courtesy, we ask that the original data source be acknowledged with the given citation.

Project Staff:
Dennis Gilfillan,
Gregg Marland,