Cum hoc ergo propter hoc

The idea that "correlation implies causation" is an example of a questionable-cause logical fallacy, in which two events occurring together are taken to have established a cause-and-effect relationship.

Examples:

1. The faster that windmills are observed to rotate, the more wind is observed.
   Therefore, wind is caused by the rotation of windmills.
2.  Young children who sleep with the light on are much more likely to develop myopia in later life.
   Therefore, sleeping with the light on causes myopia.
3. Since the 1950s, both the atmospheric CO2 level and obesity levels have increased sharply.
   Hence, atmospheric CO2 causes obesity.