ESA Codings
James Hollway
2019-07-15
esa.RmdMost existing datasets on environmental agreements classify each agreement exclusively to a single topic. However, many environmental agreements treat several overlapping or intersecting topics, and these overlaps or intersections may be of interest to researchers. gnevar’s envr_agree data non-exclusively codes environmental agreements against what we call “ESA” codes.
ESA Themes
The “ESA” coding scheme has two levels to its hierarchy. First there are three main themes:
- environments (E), or the physical setting
- species (S), or the biological subject
- activities (A), or the human salience
A Venn diagram of how these themes overlap in the environmental agreements can be seen here: 
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ESA Topics
Each of these themes also has more specific topical codes, leading to distinct two-letter codes:
Five different environmental categories are coded for here: land (EL), air (EA), oceans (EO), freshwater (EW), and resources that lie underground (EM). We also code for five different species categories: flora (SP), fauna (SM), trees (ST), fish (SF), and birds (SB). Lastly, we code for five different classes of human activity in relation to the environment: energy (AE) and agriculture (AN), science and technology (AS), military (AW), and waste (AH).
As can be seen here, the original ESA codes also serve as residual/general categories.