In contrast to mainstream theories of IR, it posits environmental issues as central to the study of international relations.
Green theory focuses on the study of global justice, international development, modernization, and security.
[1] Green perspectives in IR emerged in the 1970s as a response to the increase of transnational issues related to the environment.
[2] Green theory aligns itself with postpositivism that emerged from the so-called third (or fourth) debate of IR.
[3] Initially, the IPE wing,[4] mainly interested in environmental regimes,[3] was stronger, but subsequently many cosmopolitan theorists, like David Held, Andrew Linklater, Henry Shue, and Thomas Pogge, have made contributions related to environmental issues.