Carbon Budget
Data

Data Sources
Atmospheric CO₂. The data is provided by the US National Oceanic and Atmospheric Administration Earth System Research Laboratory. Accumulation of atmospheric CO₂ is the most accurately measured quantity in the global carbon budget with an uncertainty of about 1% or about 0.04 PgC of the 4PgC per year accumulated on average since 2000.

Emissions from CO₂ fossil fuel. CO₂ emissions from fossil fuel and other industrial processes were calculated by the Carbon Dioxide Information Analysis Center of the US Oak Ridge National Laboratory. For the period 1958 to 2006 the calculations were based on United Nations Energy Statistics and cement data from the US Geological Survey, and for the years 2007 and 2008 the calculations were based on BP energy data. Uncertainty of the global fossil fuel CO₂ emissions estimate is about ±6% (currently ±0.5 PgC). Uncertainty of emissions from individual countries can be several-fold bigger.

Emissions from land use change. CO₂ emissions from land use change were calculated by using a book-keeping method with the revised data on land use change from the Food and agriculture Organization of the United Nationals Global Forest Resource Assessment. Emissions after 2005 were extrapolated from the previous 25-year trend of 1.5 PgC per year.. We used fire emissions from the Global Fire Emissions Database vs.2 over tropical forests to provide inter-annual variability on emissions over the last three years. Uncertainty of the global estimate of land use emissions is large and considered to be ±0.7 PgC in this analysis. Emission uncertainties at the country level can be large.

Ocean CO₂ sink. The global ocean sink was estimated using an ensemble of four ocean general circulation models coupled to ocean biogeochemistry models. The models were normalized to the observed mean land and ocean sinks for 1990-2000, estimated from a range of oceanic and atmospheric observations. Models were forced with meteorological data from the US national Centers for Environmental Prediction and atmospheric CO₂ concentration. Recent trends in regional CO₂ sinks in the Southern Ocean, North Atlantic, and Pacific oceans were detected directly from repeated observations.

Land CO₂ sink. The terrestrial sink was estimated using an ensemble of 5 global vegetation models forced by observed CO₂ concentration and a combination of meteorological data from the Climatic Research Unit and US National Centers for Environmental Prediction.

Data Files

Data files and a complete description of data sources, uncertainty and calculations is available from: http://lgmacweb.env.uea.ac.uk/lequere/co2/carbon_budget.htm
CO₂ fossil-fuel emissions by country 1980-2008 from CDIAC (Excel, 43Kb). See web link: http://cdiac.ornl.gov/trends/emis/meth_reg.html

Carbon Budget Data

Carbon Budget
Data