Every month, NOAA’s National Climactic Data Center releases a “State of the Climate” report, analyzing weather trends and climate anomalies in the U.S.
This morning, they released the report for June 2012. As part of it, they did some math.
During the June 2011-June 2012 period, each of the 13 consecutive months ranked among the warmest third of their historical distribution for the first time in the 1895-present record. The odds of this occurring randomly is 1 in 1,594,323.
Brad Plumer quotes Jeff Masters from Wunderground.com, who writes:
[W]e should only see one more 13-month period so warm between now and 124,652 AD — assuming the climate is staying the same as it did during the past 118 years. These are ridiculously long odds, and it is highly unlikely that the extremity of the heat during the past 13 months could have occurred without a warming climate.
Let’s put that in context. The National Safety Council compiled an index of the odds of dying in various ways [PDF] that is both oddly reassuring and helpful for our immediate purposes.
- The odds that you might die of heart disease: 1 in 6.
- The odds that you might die of poisoning: 1 in 126.
- The odds that you might die of heatstroke: 1 in 13,217.
- The odds that you might die in a storm: 1 in 29,196.
- The odds that you might die because of bees: 1 in 79,842.
- The odds that you might die from a lightning strike: 1 in 134,906.
- The odds that you might die from a flood: 1 in 558,896.
- The odds that you might die from a fireworks discharge: 1 in 652,046.
In other words, it’s two-and-a-half times more likely that you’ll die because you had a bad Fourth than that climate change didn’t cause our warm temperatures. Also, please note: the odds of dying by storms, heatstroke, and floods are probably going to increase.
Another analogy: Powerball. The odds that you will win Powerball on any given drawing are 1 in 175,223,510 — in other words, much worse odds than that this past hot year was a random occurrence. But bear in mind that millions of people play the Powerball each time. While the odds that a particular person (read: you) wins are very small, the odds that someone wins are pretty good. So, if we have a few million different universes that have had a similar past year, the odds that one of those years occurred by chance are decent! But the odds that our particular universe is that one are very, very small.
Point being: Don’t bet on the hottest 13 months in American history being a fluke. Your time is better spent avoiding fireworks displays.