C: Hence, it is likely that the next year will be hotter than this year.

Again, the same question: if it is likely, how much faith to be have in how likely?

This is where we talk about probability and sampling, and eventually, we will discuss about probability estimates. The argument here can be either a strong argument (as in the first case) or a weak argument (as in the second case). What is going on? The next year may jolly well be hotter than this year, but if we were to make that statement only on the basis of one instance (that is this year has been hotter than last year and hence next year is going to be hotter than this year), we cannot be too certain. The probability will indeed be very low. This is the reason why case studies based on N = 1, or anecdotal evidences are not very forceful or cogent as arguments. On the other hand, in the first example, we see the same argument is being made, but in this case, we see that we argue on the basis of the fact that we have ten years' worth of data on which we bank on. This makes our probability estimate more likely than the case with only one year worth of experience.