The variable selection process was undertaken in a participatory way, by gathering the expertise from the SEACRIFOG project consortium and the wider environmental observation community through an interactive web-tool (http://seacrifog-tool.sasscal.org/; see figure 1 in supplementary material available online at stacks.iop.org/ERL/13/085003/mmedia). This tool was written in the Shiny package of the R software environment and was specifically developed for the SEACRIFOG project to capture detailed definitions and available **data** products for each variable. Contributors were also able to nominate potentially relevant variables that were missing from the variable list which were subsequently rated against the assessment criteria. The variable assessment was based on a consultative process inviting the input from a total of 210 potential contributors. The variable score was computed from a total of 40 ratings by contributors who indicated their expertise in the terrestrial (65%), oceanic (35%) and/or atmospheric domain (20%). Overall, 45% of the contributors indicated that they are either from Africa or have conducted extensive research within Africa.