Are Global Temperatures Really Rising?
As global temperature readings keep coming in, it’s useful, on occasion, to use a bit of math to determine the probability that what we are calling climate change is actually happening at random. In statistics, we call this the “null hypothesis,” i.e., that there is no (null) difference between two different sets of data. If we are to make a statement based on data, it means that we must reject the null hypothesis within a certain level of confidence.
July of 2021 was the hottest month in the 142 years, or 1704 months, that we’ve been keeping records on the subject. So, we could say that the probability that this was a random event was 1 in 1704. Now, it would be very unusual to have a year’s hottest month to occur outside of July and August, so let’s say that’s 1 in (142*2) or 1 in 284. Thus it’s not inconceivable that this could have been a random event. If I were on a jury in a criminal case and I believed that the were a 1 in 284 probability that the defendant was innocent, I’d have a hard time voting to convict.
Where one gets infinitesimal probabilities is where we have different events that all happened individually. The overall probability of their all happening is the arithmetic product of their happening individually. As it turns out, each of the hottest 7 years happened in the last 7 years. Now, the probability that 1 of them happened in the last 7 years is as follows:
7 (possible event outcomes that suggest that our belief is correct, i.e., that global warming is not happening by chance) divided by 142 (total years). If that happened, which it did, we now have 6 remaining spaces, and 141 remaining total, so 6/141. Carried to the end, we have:
7*6*5*4*3*2*1 / 142*141*140*139*138*137*136 or 1 in 250,000,000,000,000 (250 trillion). I’d have no problem convicting the guy in this case.
One last exercise involves the fact that the last month that wasn’t hotter than the 20th Century average was December 1984, meaning that every month since, all 439 of them, produced a result that had a probability of 0.5, that of a coin toss. The probability of this succession happening at random, i.e., 439 consecutive heads (or tails) is 2439, or 1 in 10134. The number of atoms in the universe is estimated to be only 1080.
So, here we can reject the null hypothesis with a staggering level of confidence. In other words, yes, this is really happening.
