Historical emissions are provided for the top-15 CO2 emitters as of 2004.  Historical emissions data, 1990-2004, come from two sources:

 

 

Non-land-use emissions: 

 

Climate Analysis Indicators Tool (CAIT) version 5.0. (Washington, DC: World Resources Institute, 2008). Available at http://cait.wri.org.

 

Note, for the Russian Federation, 1990 data at the sector level are unavailable.  In this case, we assume that 1990 sectoral emissions were proportional to 1995 emissions.

 

Land use emissions: 

 

Houghton, R.A. 2008. Carbon Flux to the Atmosphere from Land-Use Changes: 1850-2005. In TRENDS: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A

 

 

The Houghton 2008 land use analysis provides more recent and more accurate emissions figures than CAIT, which uses the figures from Houghton’s previous 2003 analysis.  In his 2008 analysis, Richard Houghton extended the time period of coverage through 2005 and also revised his previous land use emissions estimates downward.  He describes the change as follows: 

 

 

“These estimates differ from those provided in the previous versions…because they include revised rates of land-use change for the period of 1960-2000. For example, in the 1990s the annual rate of loss of natural forests in the tropics averaged 16.7 million ha in the 2000 Forest Resources Assessment (FRA) (FAO 2001) and 11.6 million ha in the 2005 Assessment (FAO 2006). The lower estimates of tropical deforestation lowered the average net flux over the period 1990-2000 from ~2.2 PgC/yr (Houghton 2003) to ~1.5 PgC/yr.”

 

Houghton’s published data are available for a subset of the Top-15 countries/regions  (US, Canada, Europe, China, former USSR), and is otherwise only available at a regional level.  For those countries in our data set that do not have specific Houghton numbers, we have made an proportional estimate based on the former and revised Houghton figures.  If, for example, Brazil represented X% of South & Central America’s land use-related emissions in the Houghton 2003 analysis (as shown in the CAIT database), we assume that Brazil accounts for the same fraction of South &  Central America in the revised regional numbers.