The theory of man-made global warming is based upon some very thin strands of evidence. It goes something like this.
The world is warming.
CO2 is increasing.
CO2 is a greenhouse gas
Therefore it must be the cause of the warming.
It takes a coincidence and assume a correlation. But then CO2 isn't the only thing that has increased at the same time temperature has gone up. So has an increase in the height of the average human being, the number of people getting high school and college diplomas, the number of women in the workforce, the percentage of the world population that speaks English, the number of countries embracing democracy, the number of people saying “can you hear me now” into a cellphone and a few hundred other trends that may or may not be causally related to each other.
Another hole in the AGW theory is the fact that although the temperature did rise from the mid-1970s to the year 2000, CO2 has been increasing since 1945. So you have warming 25 years out of 65 years of increasing CO2.
This might explain why we are being bombarded with stories of what appears to be poor science to outright fraud by the scientific organizations that have move from being scientific organizations to being partisan shills (IPCC, CRU, GISS).