In my post yesterday on the April State of the Climate report from NOAA, there was a statement that caught my attention. They said, "nine of the ten warmest 12-month periods have occurred within the past two years."
Whoa! What are the odds of that? Well, it turns out, we can figure that out and have actually done so before. I wrote a post in January about how some mathematicians calculated the probability that every year since 2000 has been one of the 20 hottest ever recorded. They calculated the odds of that to be one in 1.5 trillion. That is correct - one in 1.5 trillion!
In the post, I showed how this calculation was done. Since we know how to do the calculation, let's do the calculation for "nine of the ten warmest 12-month periods" occurring within the last two years.
First, they said the record was 136 years long. Let's assume the record started in December of that year - 1879. They don't specify and that gives us the most conservative value. That would give us the first 12-month period ending in December 1880. There would be 12 12-month periods ending every year after that, all the way to December 2014. Then there would be an additional 4 12-month periods from 2015. That gives us a total of 1624 12-month periods since the record began.
Now, in the last two years, there have been 24 12-month periods, one ending each of the 24 months of the last two years. So, the odds of one of those months randomly being in the top 10 is 24 in 1624. We have taken care of one of the top ten and one of the 24 12-month periods, that means the chances of a second top-ten 12-month period occurring in the last two years would be 23 in 1623. After that, the chances would be 22 in 1622. For a fourth period, the odds would be 21 in 1621. And, so forth.
Now, for the chances of nine of the top ten happening in the last two years would be (24/1624) * (23/1623) * (22/1622) * (21/1621) * (20/1620) * (19/1619) * (18/1618) * (17/1617) * (16/1616) = 6.174 x 10^-18. That comes out to one chance in about 1.6 x 10^17 times, or 1 chance in about 160 quadrillion times.
If we rolled the dice 160 quadrillion times, we would get these results only ONCE! In case you're wondering, if we rolled the dice one time every second, it would take us 5,070,094,050 years (including leap years). (Don't wait up, Honey. The craps game is gonna run late tonight!)
ONE TIME IN 160 QUADRILLION!
For the sake of comparison, the chances of the nine of the top ten hottest 12-month periods occurring within the last two years is about 10,000 times as unlikely as the probability of every year since 2000 being in the top 20.
Oh, by the way, global warming has stopped. Didn't you hear the deniers saying so?