Just coming from a period here in New York State where temperatures never rose above 40 degrees for almost three solid months, when I saw this headline on NBC News I thought they might be announcing something really inspiring.Summers could last six months by the end of this centuryHowever, as I dug into the article, it quickly became apparent that this was not intended to be some sort of festive discovery. Yes, it turned out to be another article on global warming straight from the Al Gore script. But if you happen to live in the Northeast, it still sounds like this could turn out to be a great deal.
Summers in the Northern Hemisphere could last nearly six months by the year 2100 if global warming continues unchecked, according to a recent study examining how climate change affects the pattern and duration of the Earth’s seasons.
The study, published last month in the journal Geophysical Research Letters, found that climate change is making summers hotter and longer, while the other three seasons are shrinking. Scientists say the irregularities could have a range of serious consequences for human health and agriculture for the environment.
“This is the biological clock for every living thing,” said the study’s lead author, Yuping Guan, a physical oceanographer at the State Key Laboratory of Tropical Oceanography at the Chinese Academy of Sciences.
Guan and his colleagues searched the daily climate data from 1952 to 2011 to determine the start and end of each Northern Hemisphere season. They found that the summers lengthened an average of 78 to 95 days over the nearly 60-year period.
I guess we’d better look at the data they’re using to find out if there’s anything in this theory. Guan’s team claims to have collected all daily climate data from 1952 to 2011. With the help of that data they worked on “determine the start and end of each Northern Hemisphere seasonBased on those numbers, they concluded that during this 59-year period, “summers were on average 78 to 95 days longer
Wow. That is certainly a shocking figure. But there is a big problem right away. I’m not sure if that was just a typo in the NBC article or if someone lost their calculator, but that figure would indicate that the summer was three months longer a decade ago than it was in the early 1950s. As if that number doesn’t sound right already, the report gets more specific, saying the other three seasons shrank by the following amounts on average.
- The winters shortened from 76 to 73 days
- The springs have been shortened from 124 days to 115 days
- Autumn shortened from 87 days to 82 days
Now, I was an English Major and our boss promised me there would be no math in this job, but those numbers even look like me. Stay here with me. Winters were three days shorter. Spings were nine days shorter. Autumn was five days shorter. I didn’t even have to take off my socks and shoes to find out that those three seasons were an average of 17 days shorter in total. But the summers were “on average 78 to 95 days longerLet’s break the difference and say that the summers were on average 87 days longer. Maybe I should get the calculator out for this one, but that means that was all year round 80 days longer than 59 years earlierDid they start selling new calendars with three extra months on them and I just never noticed?
UPDATING: I went back and checked and it turns out NBC News corrected their typo in the last paragraph above. It now says: “the summers grew from an average of 78 to 95 days long
Okay, so at least now the math works a little bit better. So they say the summers have gained 17 days, while the other three seasons have lost 17 days.
Even if we accept those numbers, the next question I had was how they “set” the beginning and end of each season. The four seasons we recognize are quite ambiguous in nature. Right now it’s a relatively balmy 60 degrees where I am and my calendar tells me that spring has officially started this weekend. So winter is over, right? But we’ve had years here in which we were hit by snow storms right up to the second week of May. Does this mean that winter lasted until May in those years, and spring only six weeks?
My point is that Guan’s team would be able to find out the precise temperature at any given weather station on any given day of the year during the period studied. But he is talking about the average “winter” which is five days shorter over a fifty-year period. I guess we just have to take his word for when winter starts and ends? What kind of science is this?
There is one last point to touch as so much of Guan’s numbers depend on temperature readings from the time Eisenhower was president. The accuracy of thermometers and other measuring equipment has changed over time. Maybe it hasn’t all changed Which a lot, but it has changed. And speaking of such small numbers of degrees, I remain skeptical if the average temperature goes up to one-tenth of a degree by exactly the amounts claimed.
In any case, I’m not going to complain about an extra week of summer. If we could only work on cutting back winter by a month or so, we’d be all set.