Environmentalists need to be un-democratic?

While deliberative democracy advocates are getting popular in recent years, and seen as the solutions to the resolving environmental conflicts by information disclosure and public engagement, the Greenpeace-style activism is obviously excluded in such discourse.

So, before taking deliberative democracy as the ultimate solution, I decide to examine its critiques and loopholes. A challenge to deliberative ideal is the ir-reversibility of the environmental problems. Mathew Humphrey in his book argued for the necessity of environmental direct actions, quoting the examples of Greenpeace and Environmental Liberation Front, before coming to the deliberation.

Democracy sometimes cannot effectively deal with the urgent environmental problems. Only direct actions can highlight its urgency. Therefore, the "un-democratic" direct actions come to the scenes.

Should we say due to the very nature of environmental problems, environmentalists do not necessarily pursue deliberative democracy? Do the environmentalists need to take care the issue of legitimacy and justifications of their actions? Are environmentalists legitimate enough to claim themselves the pioneering role and take direct action?

In my opinion, environmental direct actions can be seen macroscopically part of the "deliberative" process, though not so deliberative in itself. As a supplement to the whole discourse, the actions should still acquire a "Public Reason". Given the nature of environmental problems, how can we position direct actions in the whole course of / as an alternative to "deliberation"? This is perhaps the question I am going to ponder.