List of Acronyms
CH4 Methane
CO₂ Carbon Dioxide
EU European Union
F-gas Fluorinated gases (Hydrofluorocarbons, Perfluorocarbons, and Sulfur Hexafluoride)
GDP Gross Domestic Product
GHG Greenhouse Gas
LUCF Land use change and forestry
MtCO₂e Million metric tons of carbon dioxide equivalent
N2O Nitrous Oxide
PPP Purchasing Power Parity

This text accompanies the release of the CAIT Climate Data Explorer - Country GHG Emissions Data Collection. It is accurate as of 18 June, 2015.

Country GHG Emissions

For a complete discussion, please see the CAIT GHG Sources & Methods Documentation.

CAIT draws on key climate-relevant data from respected research centers, government agencies, and international bodies. As of June 2015, the platform contains sector-level greenhouse gas (GHG) emissions data for 185 countries and the European Union (EU) for the period 1990-2012, including emissions of the six major GHGs from most major sources and sinks. It also contains historical country-level carbon dioxide (CO₂) emissions data going back to 1850, and energy sub-sector CO₂ emissions data going back to 1971.

To produce the country GHG emissions dataset, WRI compiles data from a variety of non-governmental sources, not to replace those data reported by countries to the UNFCCC, but to complement them. Our data sources are chosen based on criteria such as completeness and relative accuracy and country datasets are produced by applying a consistent methodology.

To the extent possible, CAIT includes emissions from all greenhouse gases and major emission sources for each country. Thus, as described below, data sources cover CO₂ emissions from energy, cement manufacture, and land-use changes as well as from non-CO₂ gases. For a given country, as many as five GHG data sources may be used (including sector-level data).

CO₂ from Fossil Fuels and Cement Manufacture

Key Sources:

International Energy Agency (IEA).  2014. CO₂ Emissions from Fuel Combustion (2014 edition).  Paris, France: OECD/IEA. Available online at: http://data.iea.org/ieastore/statslisting.asp.  © OECD/IEA, [2014].

Boden, T.A., G. Marland, and R.J. Andres. 2015. Global, Regional, and National Fossil-Fuel CO₂ Emissions. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A. doi 10.3334/CDIAC/00001_V2015 Available online at: http://cdiac.ornl.gov/trends/emis/overview_2011.html . 

U.S. Energy Information Administration (EIA).  2014. International Energy Statistics Washington, DC: U.S. Department of Energy. Available online at: http://www.eia.gov/cfapps/ipdbproject/IEDIndex3.cfm?tid=90&pid;=44&aid;=8

Fossil Fuels

To maximize the benefits of the different databases, while promoting completeness and accuracy, CAIT compiles data for CO₂ from fossil fuels in the following way:

This approach has advantages and disadvantages. On the one hand, “filling” the gaps from different data sources improves the ability to make cross-country comparisons and related analyses. Yet comparability can be endangered when data points from different sources (using different methodologies) are placed side-by-side. Here, data covering the past two decades is mostly from IEA; however 50 countries are from CDIAC (and one from EIA). Similarly, the time-series data for ALL countries might include a “stitch” between 1970 and 1971 where the source changes from CDIAC to IEA, and for the 50 countries (all of which are non-Annex I countries) between 2011 and 2012 where the source changes from CDIAC to EIA.

However, these shortcomings may not be especially problematic. In many cases the difference between data for a “stitch year” is not particularly significant. Also, the 50 countries using EIA data for 2012 are generally small countries (together constituting about 0.2 percent of 2012 global emissions. In any case, users should be aware of “stitch years,” particularly when performing a trend analysis.

Cement Manufacture

Carbon dioxide is a well-known byproduct of cement manufacturing (as cement is calcined to produce calcium oxide). Estimates of CO₂ emitted during cement production, based on data from the U.S. Geological Survey, are available from CDIAC (Boden et al., 2015).

These estimates of CO₂ from cement manufacture, which cover 1928 to the present, are included in CAIT’s CO₂ National Totals for 1990-2012, although data for 2012 are considered preliminary and are only available for 66 countries and World total. CO₂ from cement manufacture can also be viewed under the Industrial Processes indicator in CAIT.

Historical CO₂ Emissions Estimates

Country boundaries have changed significantly over the past century, particularly during the years following World Wars I and II and the early 1990s. Considering that CAIT uses CO₂ emissions data going back to the 1800s, a method was required to apportion historical carbon emissions in accordance with today’s geographic boundaries. In total, WRI has made historical estimates for more than 50 countries whose borders have changed throughout the past 150 years. These include former Soviet Republics, former Yugoslav Republics, Germany (formerly split in two countries), as well as present-day countries that formerly belonged to colonial territories like French Indochina and French West Africa.

For newly formed countries, such as the independent republics of the former Soviet Union, the share of carbon emissions for the years prior to country formation is estimated based on each country’s carbon emissions in the five years immediately following its formation (or for the first five years which data are available). Specifically, the four step methodology below is used to make historical emission estimates for newly formed countries:

1. Add the emissions together for the first five years after independence or for which data are available (e.g., 1990-94 for Kazakhstan, a former Soviet Republic).
2. Add these five year totals together for all newly formed countries (e.g., sum all former Soviet Republics’ emissions from 1990-94).
3. Divide the figure obtained in step 1 by the figure obtained in step 2. This yields a percentage “share” of emissions for each newly created country. 
4. Apply the share of emissions obtained in step 3 to all pre-independence emissions data.

In step 1 above, five years is chosen rather than a single year. This is done to get a smoother average, rather than taking a single year of data, which may not be representative because of economic and social disruption that often accompanies border changes. A longer period was not used, since data many years after independence may poorly reflect that country’s relative emissions share prior to independence (of course, this might also be the case even for the five year period used). Generally, there is no precise way to attribute historical emissions to countries when they did not exist. (This is one of several reasons why some governments and observers object to using historical data). Accordingly, the estimates made by WRI (or others) should be considered only rough approximations.

For countries that have united—like Germany, Yemen, and Vietnam—the methodology is more straightforward and less subjective: emissions from the former constituent countries are simply added together. For example, the historical emissions of East and West Germany (prior to 1991) are attributed to present-day Germany. 

Emissions from Land Use Change & Forestry (LUCF)

Key Source:

FAO (Food and Agriculture Organization of the United Nations), 2014. FAOSTAT Emissions Database. Available at http://faostat3.fao.org/download/G2/*/E

The Statistic Division of the Food and Agriculture Organization of the United Nations (FAO), or FAOSTAT, reports estimates of Land Use emissions for all CAIT countries, as well as a world total, from 1990-2012 (though time series for a few countries are incomplete).

The FAO Emissions-Land Use dataset includes estimates of CO₂ emissions by sources and removal by sinks from forest land, cropland, and grassland, as well as emissions of CO₂ and non-CO₂ from fires of biomass and organic soils. Specifically:

“Land Use Total contains all the emissions and removals produced in the different Land Use sub-domains. GHG emissions and removals from Forestry and Other Land Use (FOLU) sectors consist of CO₂ and non-CO₂ gases (methane, CH₄, and nitrous oxide, N₂O), produced by aerobic and anaerobic processes, e.g. combustion and decay, and by harvesting associated with land management activities. Computed at Tier 1 and Approach 1 of the 2006 IPCC Guidelines for National GHG Inventories.

Land Use Total contains total emissions and removals for each relevant greenhouse gas (CO₂, CH₄, N₂O), expressed in CO₂ equivalents, aggregated for the following sub-domains:

Estimates of carbon stock changes are limited to above and below-ground biomass. Emissions and removals from Wetlands, Settlements and Other, are not estimated yet. ”

Consequently, this data is useful as reference only and may not coincide with LUCF emissions reported by countries to the UNFCCC. More generally, users should note that the errors and uncertainties associated with these (and other LUCF) estimates may be significant. Additional methodological information for this dataset is available on the FAOSTAT website: http://faostat3.fao.org/faostat-gateway/go/to/download/G2/*/E.  

Non-CO₂ Gases

Key Source:

EPA (U.S. Environmental Protection Agency).  2012.  “Global Non-CO₂ GHG Emissions: 1990-2030.” Washington, DC: U.S. Environmental Protection Agency. Available at http://www.epa.gov/climatechange/EPAactivities/economics/nonCO₂projections.html.

FAO (Food and Agriculture Organization of the United Nations), 2014. FAOSTAT Emissions Database. Available at http://faostat3.fao.org/download/G1/*/E

Five non-CO₂ gases are included in CAIT: methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF₆)—with HFCs, PFCs, and SF₆ being presented in CAIT as “F-gas emissions”. Estimates for these gases are drawn from EPA (2012), which reports historic and projected non-CO₂ emissions data from 1990 to 2030 in five year intervals, and FAO (2014), which reports agriculture and land-use emissions data from 1990-2012. For CAIT, we have linearly interpolated between reported EPA values to provide estimates of country, gas, and sector totals, where applicable, in the intervening years from 1990 to 2012. All non-CO₂ emissions in CAIT are expressed in CO₂ equivalents using 100-year global warming potentials found in the IPCC Second Assessment Report (IPCC, 1996a). Please note that Annex I national inventories reported to the UNFCCC in 2015 start to use global potential warming (GWP) values from IPCC Fourth Assessment Report, which might result in additional differences in our estimates and those provided by national governments.

Non-CO₂ Emissions from Agriculture

In previous iterations of CAIT, EPA (2012) has been used as the only source for non-CO₂ emissions data. As of 2015 update, FAOSTAT estimates of Agriculture Emissions are used to replace EPA as the source for non-CO₂ (CH₄ and N₂O) emissions from agriculture sector, as marked in section 4.2 below.

The FAO Emissions-Agriculture dataset includes estimates by gases (namely CH₄ and N₂O), and by sectors or subsectors from 1961 to 2012, and projections for 2030 and 2050. Only data from 1990 to 2012 are included in CAIT. Please note that time series for a few countries are not complete, for instance newly formed nations such as those from former Soviet Republics, former Yugoslav Republics, Czechoslovakia, etc. Thus Total GHG Emissions might not be available for those countries and years.

“Agriculture Total contains all the emissions produced in the different agricultural emissions sub-domains. GHG emissions from agriculture consist of non-CO₂ gases, namely methane (CH₄) and nitrous oxide (N₂O), produced by aerobic and anaerobic decomposition processes in crop and livestock production and management activities. Computed at Tier1 following IPCC Guidelines for National GHG Inventories.

Agriculture Total contains total GHG emissions, and aggregated GHG emissions for each greenhouse gases (CH₄, N₂O), expressed in CO₂ equivalents. Total agricultural emissions include the following sub-domains:

• Synthetic fertilizers (N₂O)
• Manure applied to soils (N₂O)
• Manure applied to pastures (N₂O)
• Crop residues (N₂O)
• Cultivation of organic soils (N₂O)

The methodologies followed for the estimations are described under the respective sub-domains.”

National GHG Totals

CAIT provides National Total GHG emissions with and without LUCF (Land-Use Change and Forestry) for each country. The contents of National Total calculations for non-CO₂ gases are described above. This section concerns primarily National Total calculations for Total GHGs (i.e., CO₂, CH₄, N₂O, and F-gases).

First, National Total calculations are extremely sensitive to data availability. Accordingly, the National Total GHG Emissions might not be calculated in CAIT where only non-CO₂ data are available (e.g., Eritrea and Palau in 1990 and 1991), the National Total GHG Emissions might not be an accurate reflection of a country’s true total when only partial CO₂ emissions data are available (e.g., fugitive emissions). More detailed country-by-country data availability can be viewed in Country Profile pages within CAIT.

Second, the National Total is, in general, a sum of the data from each of the individual sectors/gases. Accordingly, a National Total will include emissions from Energy, Industrial Processes, etc., summed into a single number. However, there is an exception to this general rule. In accordance with IPCC Guidelines and UNFCCC GHG inventories, emissions from land-use change and forestry (LUCF) and international bunkers are not automatically included in national totals. For LUCF, this is in part due to high data uncertainties. For emissions from International Bunker fuels (which are estimated based on the location of marine and aviation refueling), this is mainly due to difficulties in attributing international emissions to individual countries. Indicators for country GHG totals with LUCF and without LUCF are therefore presented separately. International Bunker totals are only available in the GHG Emissions by Sector table and are not included as part of a country’s total reported emissions.

As an example, the United States’ National Total for the years 1990-2012 would therefore comprise the following sector data:

• Energy sector:
• CO₂ from fossil fuel combustion (IEA, 2014; sectoral approach)
• CO₂ from gas flaring (EIA, 2014)
• Industrial Processes sector:
• CO₂ from cement manufacture (Boden et al., 2015)
• F-gases: HFCs, PFCs, and SF₆ (EPA, 2012)
• Agriculture sector:
• CH₄ and N­₂O (FAO, 2014)
• Waste sector: 
• CH₄ and N₂O (EPA, 2012)
• Land Use Change and Forestry sector (“including LUCF” indicator only): CO₂, CH₄, N₂O (FAO, 2014).
• International Bunkers are included in the “Emissions by sector” table only): CO₂ (IEA, 2014)

However, it is important to note that our calculation approach for the national totals indicators actually relies on a gas aggregation method (i.e., the sum of CO₂ emissions (see Sector 2) and non-CO₂ emissions (see Sector 4)) to produce the estimated emissions totals and “emissions by gas” estimates. This is due to limited data availability of sector-level emissions data for all countries. Thus, the sum of sectors might not coincide with the sum of gases for a particular country; this is especially true for the 50 countries which lack IEA data.

An example of how the United States’ National Total for the year 2012 would be compiled using a gas aggregation approach is as follows:

•  CO­₂ emissions total
• CO₂ from fossil fuel combustion (IEA, 2014)
• CO₂ from gas flaring (EIA, 2014)
• CO₂ from cement manufacture (Boden et al., 2015)
• CO₂ from land use change and forestry ( “with LUCF” indicator only; FAO, 2014)
• CH₄ emissions total
• CH₄ from agriculture (FAO, 2014)
• CH₄ from land use change and forestry (FAO, 2014)
• CH₄ from waste (EPA, 2012)
• CH₄ from industrial process (EPA, 2012)
• N₂O emissions total
• N₂O from agriculture (FAO, 2014)
• N₂O from land use change and forestry (FAO, 2014)
• N₂O from waste (EPA, 2012)
• N₂O from industrial process (EPA, 2012)
• F-gas emissions total (EPA, 2012)

In addition, CAIT reports the National Total CO₂ emissions from 1850 to 2012, which is included in the data subset: CO₂ Emissions Totals. For more information, please see the CAIT GHG Sources & Methods Documentation.

Socio-economic Data

Source: The World Bank World Development Indicators, last accessed 18 May, 2015

Population

Definition:
Population is based on the de facto definition of population, which counts all residents regardless of legal status or citizenship—except for refugees not permanently settled in the country of asylum, who are generally considered part of the population of their country of origin.

Units: People

GDP

Definition:
Gross domestic product (GDP) is the sum of gross value added by all resident producers in the economy plus any product taxes and minus any subsidies not included in the value of the products.

GDP in CAIT can be measured either in purchasing power parity (PPP, international dollars) or market exchange rates ($US). GDP-PPP is gross domestic product converted into international dollars using purchasing power parity rates. An international dollar has the same purchasing power in the domestic currency as a U.S. dollar has in the United States. Both measures—international dollars and US dollars—are in constant currency (i.e., adjusted for inflation) using 2011 and 2005 as the base year, respectively.

Units: GDP-PPP indicator is million chained (2011) International dollars. GDP-USD is million chained (2005) U.S. dollars.

Energy Use

Definition:
Energy Use refers to use of primary energy before transformation to other end-use fuels, which is equal to indigenous production plus imports and stock changes, minus exports and fuels supplied to ships and aircraft engaged in international transport.

Units: Energy use is reported in thousand tonnes (metric tons) of oil equivalent (ktoe).