About

This page is part of the CDIAC at App State project, which estimates carbon emissions from nations around the world. For more information, see the rest of this page or check out the CDIAC at AppState website. This is a living dataset, which may be updated over time as methods are refined or new data is incorporated. For more tools to explore the sectoral data, see the CDIAC DataDash page.

How was this dataset created?

To estimate carbon emissions since 1950, this project primarily uses fuel data from the United Nations Statistic Division’s (UNSD) Energy Statistics Database. This database uses surveys to collect information about fuel production, imports, exports, stock changes, and more for countries around the world. To estimate fuel consumption for a particular country and year, we sum the country’s fuel production and imports, then remove the exports, bunker fuels, stock changes, and some fuels used for non-energy purposes. This calculation is done for solid, liquid, and gas fuels. Gas flaring and venting are also included. By multiplying the amount of fuel used by the fraction of fuel oxidized and the carbon content of the fuel, we produce estimates of carbon emissions. These estimates quantify amounts of carbon (C) rather than carbon dioxide (CO2) specifically, and some emissions may initially be in the form of methane (e.g., from natural gas venting).

For cement production, carbon emissions are calculated using data from the USGS's Cement Statistics and Information page, the UNFCCC’s National Inventory Reports, clinker ratios from "Getting the Numbers Right," and some other sources. We quantify the amount of clinker produced and estimate the carbon emitted in the process.

For years before 1950, we rely on an earlier version of this data product, whose methodology is outlined in Andres et al., 1999. A previous version of this dataset is described in Gilfillan & Marland 2021. For discussion of some potential issues, see Andrew & Peters 2025. Work on this dataset is ongoing, and some of these issues may be resolved in the future.

Where can I find the data?

For the current version of the data, please visit CDIAC-FF on FigShare.

Can I browse the raw fuel data?

The original UN fuel data, which is the primary dataset for this product, is available to browse at UNdata. First, find a product type (e.g., conventional crude oil), and then click "view data" to see the data in tabular format.

How are bunker fuels treated?

Bunker fuels are fuels used for international commerce (e.g., shipping and aviation). Because the purposes of this fuel is to ship goods between different countries, it is difficult to assign these emissions to any particular country. In this dataset, bunker emissions are treated as follows:

• Global data: Bunker emissions are included in other fuel categories (e.g., liquid fuel) but can be visualized separately as well.
• National data: Bunker emissions are not included in other fuel categories but can be visualized separately. For each nation, the bunker fuels are the fuels loaded in that nation, regardless of where the ship/aircraft departed from or was heading to.
• Data table: Bunker emissions are not included.

Why do emissions from some countries change around 1950?

The primary dataset for this project is the United Nations Statistic Division, which starts in 1950. Prior to that, other data sources were used, potentially leading to discontinuities.

Why do I see some negative values in the data?

Negative values may be due to imperfect data, as different elements of the fuel trade (e.g., production, imports, exports, stock changes, etc.) may be calculated by different people using different methods. Small differences between large uncertain numbers can produce negative values (Boden et al., 1995).

What about other changes in the data?

Much of the data represents historical changes in fuel combustion and cement production, but some irregularities may result from limitations of the data sources or methodology. In particular, countries with small emissions may appear to have sudden shifts, so it is recommended to check the magnitudes of values to evaluate whether shifts are large or small. Some sudden changes may be the result of incomplete data.

What about nation names and national borders on the map?

The names of nations are taken from the UNSD Energy Statistics Database. National borders on the map are from rnaturalearth. These borders are for illustration purposes only and may not correspond exactly with those used in CDIAC-FF data. For example, in the CDIAC-FF data, Monaco is included with France; on the map, Monaco is not included in any region. Additionally, some small regions may not appear on the map. The map shows recent data, so former nations will also not appear. Refer to the Data Table for a more complete listing of nations (both current and former) in the dataset. These names and plotted geographic extents are taken from the sources linked above and do not necessarily reflect the political, geographic, or other beliefs of the authors.

Credit

The CDIAC-FF data product is maintained by Gregg Marland and Michael Erb at Appalachian State University. This project relies on multiple other datasets, the primary of which are referenced above.