# Carbon Emissions Data (CDIAC)

Two main equations, derived from the work of <a href="http://journals.co-action.net/index.php/tellusb/article/viewFile/14907/16719" alt="http://journals.co-action.net/index.php/tellusb/article/viewFile/14907/16719" title="http://journals.co-action.net/index.php/tellusb/article/viewFile/14907/16719">Marland and Rotty (1984)</a> and <a href="https://www.osti.gov/scitech/biblio/207068/" alt="https://www.osti.gov/scitech/biblio/207068/" title="https://www.osti.gov/scitech/biblio/207068/">Boden et. al (1995)</a>, were used in calculating carbon emissions for this data. In order to calculate the CO2 emissions from fossil fuels, three variables were used, including the amount of fuel produced and consumed (P), the fraction of the fuel that becomes oxidized (FO), and a factor for carbon content of the fuel (C). The following equation was used: $</p><p>CO<sub>2</sub><sub>i</sub> = (P<sub>i</sub>) (FO<sub>i</sub>) (C<sub>i</sub>)/,[itex] </p><p>where <i>i</i> is the group of fuel being calculated, chosen from gases, liquids, or solids. This equation was used to calculate global CO<sub>2</sub> estimates for each fuel group. A total of the caclulations for each group was then used to calculate the total CO<sub>2</sub> emissions for each country, used in IFs. In order to estimate the amount of fuel consumed (P), another equation was used: </p><p>Consumption&#160; = production + imports - exports - bunkers - changes in stocks </p><p>where "bunkers" refers to fuel used by ships and aircraft used in international trade. </p> <h2> Negative Emissions </h2> <p>There are negative emissions for a number of countries in this dataset, for Australia in the 1950s, Venezuela in 1930, and Iran in 1950, among others. A possible explanation has been provided by the CDIAC in their discussion of the CO<sub>2</sub> trends for the <a href="http://cdiac.ornl.gov/trends/emis/tre_ira.html" alt="http://cdiac.ornl.gov/trends/emis/tre_ira.html" title="http://cdiac.ornl.gov/trends/emis/tre_ira.html">Islamic Republic of Iran</a>: </p><p><i>Energy statistics for the Islamic Republic of Iran in the early 1950s and the corresponding CO<sub>2</sub> emissions estimates should be used with caution. Domestic fuel consumption is calculated as the difference between production plus imports and exports plus changes in stocks. When both production and exports are very large and very similar, a small error in either estimate can make it appear that domestic consumption was negative.</i> </p><p>This is a plausible explanation for other countries with negative emissions, as they were all for years in the late 1800s or early to mid 1900s, or had poor data availability during the years their emissions appear negative. </p> <h2> Pulling CDIAC Fossil Fuel CO<sub>2</sub> Emissions Data </h2> <p>For general instructions on how to import data into IFs, visit the <a href="http://pardee.du.edu/wiki/index.php?title=Importing_data_(general_instructions)" alt="http://pardee.du.edu/wiki/index.php?title=Importing_data_(general_instructions)" title="http://pardee.du.edu/wiki/index.php?title=Importing_data_(general_instructions)">data import page</a>. </p>$