Way back in the last millenium, I attended a seminar put on by Dr. Weaver. At that time, he was an untenured professor doing climatology. Dot Com was about to explode and oil was less than $15/barrel. Nobody except a few grad students like myself knew or cared about his research.
He reported on ice core drilling in Greenland and mentioned that periods where the average temperature was higher coincided with a higher standard deviation in temperature. In other words, when the average temperature is warmer, the variability of the weather increases. Coupled with climate theory that predicts increasing temperature with increasing CO2 concentration, you get a pretty reasonable argument that the weather is going to get bad in the future.
At that time, he was part of a research institute and what he had to say was just part of his research. He was doing his job and didn't have any incentives from any lobby groups outside academia because at that time, there weren't any. There were no Wall Street backroom boys slipping him dollars, nor was any greenwash organization encouraging him.
I have a hard time believing he falsified data given the circumstances and time. If you are still skeptical, I encourage you to try reading some of the papers he put out or contact him or the climatology center to get a look at the data.