Pravda has an interesting article on the problems of predictions based on observations when related to global warming.

The article includes the following rather amusing joke which does a better job at explaining the difficulties of making predictions based on observation than a myriad other articles (emphasis mine) :

The unusually hot summer that devastated Russia this year once again reminded of a trendy horror story called “global warming.” Proponents of this hypothesis, talking about their cause, have entirely lost sight of an abnormally cold winter in the Southern Hemisphere. Their opponents said that single point cannot be used for plotting. However, reasonable arguments both for and against the warming have not been presented to the general public.

There is an old joke about a weather station in Chukotka.

Once the Chukchi came to their shaman and asked him whether it will be a cold winter. He replied that the winter will be cold, and told them to gather plenty of firewood. But after some time he decided to test his prediction, and went to the nearest weather station. Meteorologist looked out of the window, and told the shaman, that winter, no doubt, will be cold, since the Chukchi are actively collecting firewood.

Studies by many scientists who promise global warming are not much different from observations of that meteorologist. If you analyze all the methods they use, it is astonishing that at least something can be predicted on the basis of their findings.

Remember that one next time you read the BBC’s latest propaganda piece.