Have you seen Davis Guggenheim's documentary "An Inconvenient Truth" ("Une vérité qui dérange" en Français) ? The latest docu-blockbuster showcases Al Gore's crusade to raise the world's awareness on the global climate crisis is a powerful example of the use of visual information to convince viewers of the reality of its key aspects, like the raising levels of carbon dioxyde.

Some of this borrows from the best of Hollywood craftmanship or Pentagon's psychological operations toolbox … this time for a good cause ! I was convinced long before the film that man could have an effect on global environment issues but like others I had trouble with the fact that many climate scientists admit they could not prove the rising carbon level was truly causing sea level or temperature to increase. The case made by the novel "State of Fear" ("Etat d'urgence" en Français) from Michael Crichton was quite persuasive in its own sense … one could not win a legal case on this issue ! But to Al Gore's credit, his slideshow really moves mountains : as the famous French photograph Yann Arthus-Bertrand put it during the conference that followed the showing, he has been trying for 10 years to no avail to convince some of his friends who were turned around by the film !

The most convincing part is probably the rapid succession of graphs going through the roof and video images of hurricanes, floods, tsunamis, … As well as superimposing 2 graphs to show the evidence without having to prove it.

To those who see PowerPoint as evil … Al Gore's slideshow will prove hard to fight in the minds of all who saw it ! The video images speak to the emotional self, while the graphs speak to the rational self. In the minds of most people graphs can not lie as they represent hard facts that can be traced back to a source that can be challenged by experts, whom they trust to voice their disagreement if it is wrong. But in our information overloaded society such a disagreement will be hard to hear … and to weigh against contradictive analyses / opinions.

Addition : I recently found another example (that may have been to some extent 'inspired' by Al Gore's) : a lesson in economics (amongst other things showing the impact of the level of taxes on growth) by the the Medef's president Laurence Parisot at the last General Assembly in January.