Read here. Very informative and interesting review of the scientific requirements for validating the correctness of a theory. In a nutshell:
"This means that predictions made by scientific theories are typically conditional and limited in scope—taking the form of a hypothetical assertion stating that certain specified changes will come about if particular preceding events take place. Conversely, if X takes place and Y does not, then the hypothesis must be false."
In the case of the CO2-based AGW theory, what predictions have been made by the theory and what has been the empirical evidence outcome, proving or disproving the theory?
"In this case it must make specific predictions that permit the theory to be falsified. So what are the strongest predictions made by the AGW theory? Let us first identify AGW's primary tenant. That is that human CO2 emissions are causing Earth's temperature to rise. What are the observed facts?
- Are CO2 levels rising? The evidence seems to indicate that this is true.
- Is the increase in atmospheric CO2 being caused by human activity? There is some debate over how much is due to nature and how much due to man but let's simply accept this assertion as well.
- What does AGW theory predict should happen as a result of these conditions? The obvious answer is that global temperature should rise."
"In fact, back in 1988, NASA’s in house climate alarmist James Hansen presented a prediction of steadily rising temperatures to Congress. Has this prediction been substantiated, proving that AGW is a valid theory?....Not only was Hansen wrong back in 1988, all the models used by all the AGW proponents managed to miss the leveling off and slight downturn in temperature rise that started in 1995."
"Dr. Phil Jones from the UK's Climate Research Unit (CRU)....is quoted as saying that for the past 15 years there has been no “statistically significant” warming. Yet the yearly averaged atmospheric CO2 level has continued to steadily rise. What we have here, as Popper showed, is a false theory."
