explain the term 'global commons'

The term 'global commons' refers to resources that are shared and accessible by all, with no single governing country or power. The four notable global commons include the high seas, the atmosphere, outer-space and the only commonly shared land-mass, Antarctica. The term may have a broader meaning, extended to resources such as cyber-space, language and science. Due to no single governing power, these resources are at risk of over-exploitation, such as extraction of oil reserves in Antarctica.