If you are disappointed/angry (for example at the propaganda/mis-representation of science) that was The Great Global Warming Swindle here is where to complain:
http://www.ofcom.org.uk/complain/pro...?itemid=286480
Complain to C4 itself:
http://help.channel4.com/SRVS/CGI-BI...ARSET_TITLE=TV
Complain to the advertisers:
Volkswagon, Hastings & Direct, Bradford & Bingley, Visa, Yakurt, Orange, Audi, Virgin Media, Mitchelin, Zurich finance, Wrigley (orbit gum), Ing Direct (finance), Magners Cider, confused.com (insurance), Christian Dior (J'adore), Kraft foods (Toblerone, Cote d'or), Nat West, Love Films, Citreon, Nissan, Expedia, Microsoft, Ibuleve, Otex ear drops.
Notice how many car and finance adverts there were. I let The Independent off because they published an article criticising the documentary.