If I hadn't been corrected by some friends the other day, I would have titled this post "Another Cool Summer in Porto" like this post from a year ago.
My friends grew up in Porto, and told me that the summers we've been having haven't been different from normal. If anything, they've been warmer than normal. People going out at night without putting a jacket on never happened when they were young. Such warm nights are a new phenomenon.
This was news to me, because in my sixteen years in Porto, going out at night without a jacket has been the norm during summers. It's only in recent years that this has become less normal.
I found this difference in perspective interesting, because it illustrates a few things when it comes to the climate debate. We tend to view as normal whatever the conditions were during our formative years in a place. Recent variations are compared to those times, and any deviations are seen as abnormal. In the case of my friends, the 1980s are their reference frame. In my case, it's the late 2000s.
Another factor that plays into this is what we learned as kids regarding the climate. I'm old enough to have been taught that we're heading into a grand ice age, similar to what we had for about 100,000 years until the Holocene. We were taught climate history, and the things we were told were the sort of stories that can be found in this online resource. With no stories nearly as compelling in defence of man made global warming, I've stuck with the prevalent thinking from the 1970s.
Then, there's confirmation bias. We tend to look for evidence that supports our preconceive notion of things. People who believe in man made climate change latch onto evidence for it. I look for the opposite.
There's nothing wrong with confirmation bias, by the way. It only becomes a problem when some people think themselves immune to it. Once a group of people declare their view as correct and without any kind of confirmation bias, we know we're dealing with charlatans. Such people aren't interested in truth. They're only concerned about being right.
So I admit openly that my views are skewed by confirmation bias. I remain convinced that another grand ice age is inevitable, and relatively close at hand. We're at the end of a warm period that has lasted 10,000 years, and we're heading into a cold period that will last 100,000 years. The Holocene has been a period of unusual climate stability and warmth. However, the trend has been towards a colder climate over the last several thousand years. The warm peak happened at the beginning of the period, some 8,000 years ago.
At the start of the Holocene, all glaciers in Norway melted away, and the land was covered in the sort of forest that we associate with Germany rather than Norway. But the glaciers came back about 6,000 years ago. The Jostedal glacier appeared. It lies on top of a forest that used to grow there. We know this because bits and pieces of forest emerges from it every now and again, and these pieces are dated to be 6,000 years old.
The Jostedal glacier is the mother of minor side arms such as the Nigard glacier and the Briksdal glacier. These are tiny in comparison. They come and go, but the Jostedal glacier persists. The Nigard glacier consumed a farm a few hundred years back, but is now pretty much gone. The Briksdal glacier is also gone. The melting period that started back in the 1750s has continued to this day. But I'm nevertheless sure that these minor glaciers will come back. That's my confirmation bias kicking in.
Another interesting fact is that Hardangervidda was covered in a lush forest as recently as the Medieval warm period. There are some paintings made by a painter back in the early 1800s that depict the remnants of such a forest decomposing in a bog.
Hardangervidda is today a barren plain with only moss and grass growing here and there. However, I've spent many summers at a cabin in the area, and trees are reappearing at the fringes of Hardangervidda. Looking at pictures from the cabin that were taken a hundred years ago, it's as if the cabin was situated in the centre of Hardangervidda. Today, the cabin is surrounded by five meter tall birch trees. There's thick turf on the ground, lush grass and wildlife everywhere. Yet, I'm convinced that this too will pass.
We're looking at relatively minor cycles, typical of the Holocene, and to make a big deal out of this is silly. There's nothing out of the ordinary going on. The climate is nowhere near as warm as it was at the beginning of the Holocene, some 10,000 years ago. It's not even close to being as warm as it was during the medieval warm period. But it's warmer by quite a bit since the 1750s, and this has some people worked up in a frenzy as if the end of the world is near.
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| Sidearm of the Jostedal glacier |
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