Phases of a public scare

1. Discovery
Discovering of a believable threat. In 1910 scientists discovered that Halley’s Coment contained significant levels of cyanide. Or they “discover” that bird flu (like all flu) has caused deaths. The millennium bug is “discovered” as a story which taps into the fear of new technology and “crazed robots” on TV.
2. Dismissal
The normal reaction of scares is to dismiss them as most just go away.
3. Public discussion
For a scare to be successful an apparently credible group with public sympathy must start taking the scare seriously. This is often a group who try to capitalise on the scare to bolster support for their cause. It could be environmentalists trying to use the scare to flame public opposition or it could be academics trying to create public interest to get funding or it could be drug companies or windmill companies trying to make a profit.
4. Repetition
No scare succeeds without constant repetition through the media.
5. Acceptance
Eventually by repeating the possibility of a scare, large numbers of the public and even those who thought they knew they were just trying to get publicity like the academic community begin to believe the scare is real.
6. Commercialisation
Eventually commercial companies realise that there is a lot of money to be made from the scare. This opens the floodgates for serious money which goes into lobbying government to spend huge amounts of money which just happens to benefit commercial companies. Wind energy is an obvious example so are flu vaccines.
7. Frenzy of action
… by some usually just as others start realising there is no problem.
8. Witch-hunt of the “deniers”.
Those employed for the noble cause of desperately  trying to save humanity (almost always through some massive media campaign to “raise awareness” without any real action) are in no mood to hear even reasonable scepticism. More importantly as advertising gurus, they have just the tools and necessary (government) funding to create a witch hunt against any sceptics.
8. Failure of the predictions
However publicity can’t make something true. Soon the sceptics are being proved right. People don’t die from bird flu. The sea does not inundate the land. The millennium comes & goes without problem. The press get more and more embarrassed carrying articles about people who haven’t died and the witch hunts look more and more like a publicly funded witch-hunt of those who were right.
9. Pretend it never happened.
As the sceptics get proven right the media find a growingly hostile audience for the publicly funded alarmist machine that was set up to convince people they were wrong to be sceptical. There follows an embarrassed silence when only the most die hard zealots continue to print material promoting the scare.
10. The phoney end

Often scares just get forgotten and so they just fade away. We never heard why 50millinon doses of a useless drug were bought to combat Bird, the public never got updated that the ozone hole got better all by itself.
The chief culprit for these scares was the media who created the scare and so they have absolutely little interest following up the story after the scare fades.
11. The stink in the tail
But sometimes, like the global warming scare, government have wasted huge amounts of money and committed themselves to useless action which cannot just be stopped. Sometimes the cost is not just another few hundred million that can be lost in a budget, but it is real lives and real people suffering. Sometimes, no matter how they would wish to, the press just can’t ignore this.
… so that we get …
11. Search for the “guilty”
When scares cannot just be left to be forgotten, the next phase is the search for the “guilty”. Because the real guilt for these scares lies with the government and media who will ever accept blame themselves. So, they must find a scapegoat to take the blame in their place.
12. Punishment of the innocent and praise to the non-participants.
And the easiest people to blame are those who were entirely innocent, had no involvement or worse … those who raised the alarm that it was a scare.
13. Draconian measures
In the UK, after each of these fails, if public pressure is sufficient, we have a massive report several years after the event, where some person is scapegoated, those officials whose crazy policies caused the problem and who are actually responsible are vindicated. And every interest group sees the inquiry as a way to lobby for this or that draconian change which they assure the inquiry will “fix” the problem and ensure it can never happen again … followed very shortly by …. the next scare often directly caused by the supposed “fix”.