Anthropogenic CO2 emission uncertainty calculation tool CHE_UNC_APP

The CHE_UNC_APP enables you to calculate anthropogenic CO2 emission uncertainties in accordance with the Tier 1 IPCC2006 approach (i.e. with prescribed Emission Factors and Activity Data and assigned uncertainty bounds) using emission budgets (yearly or monthly) in kilotonne as input data.

This App is designed to be used in the Linux environment. By default, all scripts are executable, pre-compiled and run sequentially one after the other once the main bash script “CHE_Uncertainty” is started.

Provided files include:

(i) README_CHE_UncertaintyGeneration_App.docx - all necessary information on how to install and run uncertainty calculation tool on users machine, how to customise tool according to the users needs, detailed information for each script and resulting files;

(ii) CHE_UncertaintyGeneration_App.zip - archived folder with all executable scripts, input data, and folders to successfully install and run tool on users machine;

(iii) tmp_data_example.zip - archived folder with all tool's intermediate results (txt files and plots) based on provided input data and default assumptions;

(iv) res_example.zip - archived folder with all tool's final results based on provided input data and default assumptions.

Anthropogenic CO2 emission uncertainties are calculated using the simplest error propagation method considering a correction for underestimation (underestimation comparing to the use of a more sophisticated approach, e.g. Monte-Carlo), and assuming that there is no correlation between different countries and/or IPCC2006 activities. Other assumptions, if any, are noted next to each IPCC2006 activity in “data/ MAIN_INFO.xlsx” file. Uncertainties are calculated taking into account the development level of a country’s statistical systems (i.e. countries with well- and less well-developed statistical systems).

In general, uncertainties are calculated in 3 steps:

(i) the combination of the initial 92 IPCC2006 activity uncertainties until “sectors” for which the user has provided emission budget data – often emission budgets are provided not per each IPCC2006 activity but for several activities together (usually due to measuring/reporting limitations), meaning the user does not know the exact proportion of each activity in the emission data and it has to be assumed that all activities emit in equal proportions;

(ii) further grouping of the combined IPCC2006 activities (“sectors”) according to the user needs (until “groups”) and calculation of “group” yearly uncertainties – usually there are computational restrictions for operational modelling, e.g. the time step can’t be too short, number of emission types taken into account by the model can’t be too large, etc., meaning the user has to merge some “sectors” together even though emission budget data are present. In addition, instantaneous emission data might be rather uncertain and hard to evaluate for different emission types all over the world, so IPCC2006 and its 2019 Refinements provide the best possible information on how certain emissions are, meaning yearly uncertainties;

(iii) calculation of “group” monthly uncertainties starting from the yearly uncertainties – sometimes, for operational modelling a yearly timescale is insufficient and monthly data becomes more suitable.

Main terminology used: activity – IPCC2006 activities which result in anthropogenic CO2 emissions in the yearly budget; “sector” – combination of different activities that are measured/reported together (that have emission budget data); “group” – combination of different “sectors”, that have emission budget data, purely for modelling/comparison needs.

This app contains the following input information:

(i) “data/ Budgets2015” (“data/ Budgets2015_[1..12]” – same but with monthly data) – anthropogenic CO2 emission 2015 yearly budgets, in kilotonne, for 242+1 geographical entities (international aviation and shipping are assigned as ocean “SEA”). Monthly files provide emission budgets for the month in question multiplied by 12 months - to get the real monthly emission budget values provided need to be multiplied by the number of days in the month in question and divided by 365 days;

(ii) “data/ CountryGrouping” (“data/ CountryGrouping_EXTRA” – same but for additional countries “E28”, “GL1”, “GL2”, “GLB”, see below for more information) – list of geographical entities with the assigned development level of their statistical systems (i.e. countries with well- and less well-developed statistical systems);

(iii) “data/ UncertaintiesIPCC2006” – list of IPCC2006 activities and their upper and lower uncertainty bounds. The list contains only 92 IPCC2006 activities which result in anthropogenic CO2 emissions in the yearly budget;

(iv) “data/ MAIN_INFO” – file in EXCEL format with mainly the same information as above but with some extra notes to aid the user in getting familiar with the input data used.

This app can be easily customised based on specific user needs:

(i) to change yearly emission budgets the user needs to simply replace the “data/ Budgets2015” values with the updated emission budget data (and “data/ Budgets2015_[1..12]” to change monthly emission budgets);

(ii) to change the country’s statistical systems development level the user needs to replace the “data/ CountryGrouping” (and “data/ CountryGrouping_EXTRA” to change additional counties statistical systems development level) letters with the updated development levels, where “A” corresponds to a country with a well-developed statistical system and “N” to a country with a less well-developed statistical system;

(iii) to change the IPCC2006 activity uncertainty values the user needs to replace the “data/ UncertaintiesIPCC2006” values with updated uncertainty lower and upper bounds;

(iv) to change the way IPCC2006 activities are combined into “sectors” the user needs to replace the “data/ UncertaintiesIPCC2006” values with the updated numbers (if emission budgets are present for each activity then the numbers should be sequential from 1 to 92 – same as the first column; if some activities have to be left out from the computation – they should be numbered as 0);

(v) to change the way “sectors” should be combined further into “groups” the user needs to replace the “data/ UncertaintiesIPCC2006” values with the updated numbers.