It is perhaps natural that the British and Irish Earth First! movements in particular would seek inspiration from and consciously seek linkages with Celtic identities, given that the ancient Celts are commonly portrayed as being more in touch with nature than modern consumer society.
The British and Irish Earth First! movements may have been influenced by Celtic identities due to their historical connection to the natural world, which is often seen as a more balanced relationship between humans and the environment compared to contemporary consumer society's emphasis on materialism.