By Roger Harrabin
Environment analyst, BBC News
More people die on the roads around the world than from common flu
Modern society is wobbly around "risk". The same newspaper editors who pillory head teachers for banning conkers are swift to castigate the authorities for any "avoidable" death.
So it is perhaps understandable that people in the firing line of blame sometimes take a precautionary approach that can look like an over-reaction.
On swine flu we have had earnest re-assurances from President Obama and Gordon Brown that all necessary precautions are in place and that the response is proportionate to the threat.
But it's hard to tell a proportionate response if your risks are hard or impossible to quantify.
In 1990 came the scare over vCJD from beef. We were warned that thousands of people might die.
And tens of thousands of cows were destroyed to stop the spread of BSE - the bovine version of vCJD. The final death toll from vCJD stands at 164.
In 2002 we had a global panic about Sars - a disease described in parts of the media as probably worse than Aids. It caused 774 deaths worldwide.
In the flap over bird flu in 2006 we were told that one in four Britons might die. In fact the global death toll was 257.
What we can't know in any of these cases is how much precautionary action by the authorities mitigated the health risk, or whether the health professionals were crying wolf.
And we cannot know how far media hype contributed to policy-makers' zealotry actions.
The virologist John Oxford, for instance, was berated on BBC Radio 4's Today programme by columnist Simon Jenkins for describing a swine flu "Armageddon".
He replied that he had been asked by a journalist to speculate on an Armageddon scenario - which is what he did.
He went on to say that swine flu was probably being beaten, and that he was more worried about on-going bird flu. It is a fact that crises sell newspapers and increase TV audiences.
To put the scares in perspective, about half-a-million people die from common flus in an average year.
More than a million die on the roads. But governments are often more easily moved to tackle a short-term crisis than a long-term crisis, and on-going situations like road deaths don't register as news.
Take the two risks identified by the physicist Stephen Hawking as the biggest threats to humankind - climate change and a GM virus modified by terrorists with no human immune response.
On climate the world's politicians are failing to mitigate the risk as described by scientists. On the GM terror, there may be little biologically they can do.
Policy-makers goaded by media headlines in the current flu outbreak are faced with one uncomfortable certainty as they ponder future precautions - they are damned if they do and damned if they don't.