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 text below or check out the main CDIAC at AppState website. This is a living dataset, which may be updated over time as methods are refined or new data is incorporated.

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 emission values quantify amounts of carbon rather than carbon dioxide 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 recent overview of this project can be found in Gilfillan & Marland 2021. For discussion of some additional issues, see Andrew & Peters 2025. Work on this dataset is ongoing, and some of these issues may be resolved in the future.

Can I browse the raw 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?

Because bunker fuels are used for international commerce, it is difficult to assign them to a particular country. In this dataset, bunker emissions are treated as follows:

• Global figure: Bunker emissions are included in other fuel categories (e.g., liquid fuel) but can be visualized separately as well.
• National figures: Bunker emissions are not included in other fuel categories but can be visualized separately. For each nation, the bunker fuels shown correspond to the fuels loaded in that nation, regardless of where they are going.
• 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 check the magnitudes of values to evaluate whether changes are large or small. Sudden changes may result from incomplete data.

What about national borders on the map?

National borders on the map are from rnaturalearth. These borders are for illustration purposes only and may not correspond exactly with those used when calculating the data. For example, in the carbon emission dataset, 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 older nations will also not appear. Refer to the Data Table for a more complete listing of nations (both current and former) in the dataset.

Credit

The CDIAC-FF data product is maintained by Gregg Marland and Michael Erb at Appalachian State University. The main sources of data used in this product are referenced above.