As you know, there are fewer and fewer pipe smokers. This can be explained using correlations.
First, 100% of all people eating carrots have died, or will die at some point.
And after much mulling over the subject, there appears to be a sharp decline in pipe smokers beginning in the 1970’s, about the same time that microwave ovens became available to the general public.
Therefore: Carrots cause death, the decrease in pirates causes global warming, and microwaves explain the decline in pipe smoking.