In the 1970s, acid rain and other ecological concerns were at the fore and it was at this time that climate change first became a pressing political issue. But the concern wasn't global warming -- it was the threat of a new ice age. So how did the scientific community manage to get it so very wrong? Uncovered 30 years later, the secret government organisation known as "Jason", produces the first official report on global warming in 1979. Fast forward to the mid 1980s and global warming had already become a serious political issue. However, it is not until the 1990s that the issue turns out to become one of the biggest scientific controversies of the age...