TapeCutter writes: In 1958 the US National Academies of Science (NAS) warned the US government that they had detected a robust Anthropogenic Global Warming (AGW) signal, they have not changed their mind on that claim for 57 years. Like the modern day Al Gore, Frank Capra publicized the possible effects in a popular documentary (video). Today we have news of a study from Melbourne University claiming the effects of AGW first became evident in the mid 20th century. In other words, the NAS could not have picked up the signal much earlier than they actually did. The fact that the last serious scientific objection to AGW (as a theory) was overcome in the mid 20th century by improving spectrometers in heat seeking missile was a remarkable coincidence, NAS took full advantage of that opportunity.