Scientists, journalists and public figures in Australia who speak out on the subject of climate change are paying a steep price: harassment, threats to their lives and threats to the safety of their children.

Professor Clive Hamilton, an author and Greens Party candidate and founder of progressive think tank The Australia Institute, says he and others have been victims of cyber attacks arranged by “denialist organizations”, which aim to silence climate scientists and environmental journalists.

Hamilton wrote on ABC’s The Drum Unleashed, “Apart from the volume and viciousness of the e-mails, the campaign has two features — it is mostly anonymous and it appears to be orchestrated.”

Some of the e-mails are merely insulting, calling various scientists including David Karoly at the University of Melbourne and professors Andy Pitman and Ben McNeil at the UNSW “arrogant, conceited, ignorant”, but others went much further than that. The threats against scientists’ families are too offensive to repeat.

Among the more polite e-mail snippets quoted by Hamilton:

"Burn in hell. Or in the main street, when the Australian public finally lynchs [sic] you."

"It is probably not to [sic] extreme to suggest that your actions (deceitful) were so criminal to be compared with Hitler, Stalin and Pol Pot. It is called treason and genocide.”

"If we see you continue, we will get extremely organised and precise against you."

The e-mails come in by the dozens over periods of a few hours.

“It's fair to assume operatives in these organisations constantly monitor the media and, when a story or interview they don't like appears, send messages out to lists of supporters, linking to the comments, providing the scientist's e-mail address and urging them to let him or her know what they think,” writes Hamilton.