One of the side-effects of being housebound in the evening with two toddlers is that you can end up in a cinematic timewarp – seeing films months if not years after your mates have seen them in the cinema.

As such I finally got round to seeing Al Gore’s ‘An Inconvenient Truth’ this week. As well as a great demonstration of how to present data (although I am not sure how I would get to use an electric lift when showing a client a media analysis chart!), it of course raises some startling issues.

Leaving the imminent destruction of the planet to one side, one point that got my attention was the discrepancy between the global warming debate at the scientific level compared to how it has subsequently been portrayed in the media. Al Gore states that "out of 925 peer-review scientific journals about global warming, there was no disagreement. Zero". However, media analysis of newspaper and magazine articles has shown that 57% question the fact of global warming with 43% supporting it.

Al Gore draws comparison between the global warming debate and what went on the tobacco industry several decades earlier. Despite strong medical evidence, there were doubts about a link between smoking and lung disease. The tobacco companies deliberately exaggerated the scepticism in the media.

The exact opposite can often happen. In 1998, the Lancet published a research paper that suggested a link between the MMR jab and autism. Most scientific studies disagreed with the article and it has since been discredited but that hasn't stopped a decade of controversy, a fall in inoculation rates and an increase in the number of potentially life-threatening cases of measles and mumps.

So why is the media likely to distort the truth and exaggerate controversy. One answer is that minority interest groups are very persistent in getting their message across. Another one is simply that it sells more newspapers!

Chris Anderson, curator of the annual Technology, Entertainment and Design Conference recently tried to explain this phenomenon. The Edge is a network of leading thinkers in their various fields. Every year ‘The Annual Edge Question’ is sent out to the network and answers are published on the website and as a book. The latest question is "what are you optimistic about?". Chris Anderson answered this with: "the unending stream of bad news is itself flawed".

His argument is that we have evolved to react more strongly to dramatic stories than to abstract facts in order to survive our village being burned down or being chased by a sabre toothed tiger! Hence the fact that 'Rottweiler Savages Baby" is a bigger story than "Poverty Percentage Falls".

The news agenda appears to revolve around a never-ending cycle of wars, massacres and bombings. However, a report by the University of Columbia's Human Security Center (which received little attention) showed that the numbers of armed conflicts had fallen by 40 percent in a little over a decade, and that the number of fatalities had also fallen. This effect is exaggerated by the increasing competition between media owners increasingly desperate for a better foothold in an environment of falling sales.

Surely if bad, ‘dramatic’ news sells more newspapers than good but dull news, then we should be seeing trends emerging in our own clients’ media analysis data. Indeed this is the case. We recently published our Metrica Numbers report, which brought together meta-data from more than 3 million articles from 700 different organisations over the last decade. Although most coverage is favourable (92%), over the last ten years the amount of unfavourable coverage has steadily increased, rising fourfold from around 2% in 1997 to about 8% in 2007.

The media is the lens through which most people see the world. And while a lens can bend light, the media can frequently distort reality.  If these trends continue, then there will be an increasing need for tight planning, measurement and management of public relations, particularly in the areas of crisis management, lobbying and corporate and social responsibility.