This May I started checking our beech hedge for signs of it coming into leaf because I had noticed that much of the hedge came out of bud within a day and had recorded the date last year as May 5th. So, I started watching and waiting and a good 12 days later I reached the same stage. At the time I just took it as an example of how variable the climate was.
But last week a journalist friend spontaneously asked me about the colder weather as they had recently run an article saying it was set to be the coldest June in 40 years. I must admit I was stumped to answer. I mentioned that some people were talking about sun spots and this possibly causing cooling, but that was something longer term. However, June continued cold and now it’s well past the summer solstice and we still have not turned off our central heating.
So, I thought I’d try to see if there’s a general explanation for the colder weather.
The best answer to the question I found was this:
“Up till now and really since the beginning of 2015, there’s been a fight between the Azores high and Iceland low. The weather has always been that drier and more settled across the South of the UK while more changeable in the North.” (link)
That doesn’t strike me as much of an explanation. And it’s not just Scotland that has been experiencing this colder weather. German has also been experiencing unusually colder weather: (notrickszone.com)
And the US has had quite a bit of colder weather this year:
However, I’m always sceptical of these types of videos picking out material as it is all too easy to pick out an odd place with abnormal weather when most places are normal, or even to pick places where it is pretty “normal” to have cold weather.
Three month ago the Mail ran an article: If you thought the Polar Vortex was bad, wait til you get hit by the Siberian Express! Rare cold weather phenomenon brings the coldest temperatures in 100 years to South
And we mustn’t forget that there may now be money coming into the sceptic cause because it has become an issue in the US presidential race. So, it’s not impossible that this is a highly selective set of clips.
Cold weather is a killer
let’s not forget that cold is the real killer: “Lancet: Colder weather kills 20x as many as hot” That is certainly true in temperate areas like the UK. I understand even in India more people die in the winter. However none of the countries in the lancet study are “third world” which tend to be the warmer countries of Africa. But even so I wouldn’t be surprised if globally there are more deaths in the winter than summer.
Historically most of the major famines in the British Isles are associated with colder periods in the Central England Temperature data:
I did quite a lot of investigation of the 1690 famine because of its importance in bringing about the Union of England and Scotland. From what I found, it appears that the 1690s were both colder & wetter. The presence of snow on the Cairngorms in mid summer suggests it was around 2C cooler. That was enough to kill between a 1/5 and a 1/3 of the population. Looking at evidence from other places, it appears the deaths were probably related to poor harvests rather than a direct result of the cold. One strong candidate is Ergot fungus, a fungus that attacks cereals and poisons the flour.
There’s strong evidence in the symptoms of those involved that the Salem witch trials of 1692 in the US were caused by Ergot fungus. There’s also evidence that climate affected the Darien scheme as the scheme was advised by someone who had been in the area not long before who should have known it if was unsuitable. The Darien scheme soaked up much of the remaining money of Scotland after the 1690 famines and its failure effectively left Scotland bankrupt and with little choice but union with England.
But the megasaurus in the Dunny is the idea that our climate may be affected by the sunspot low. Personally I’ve looked at this for a while and whilst there’s good evidence solar activity effects the climate, I try not to take a view beyond saying it is probably less that some (6C) say and certainly more than the IPCC suggest (0C).
However if you were to ask the right person I’m sure they would go on record saying it is “the lowest sunspot cycle since 1880″. That sounds impression until you see below that there’s only by 12 sunspot cycles in that period. So, it’s a bit like saying “the coldest day this fortnight”. It’s not that unusual.
This sunspot cycle is very low and there’s good reason to link low sunspot activity to colder periods. However, Roger Tallbloke recently talked about the cycle and concluded: “Our results do not indicate a drastic change of the solar cycle toward a grand minimum in the near future.” In reality I don’t think anyone knows much except we know it is possible there will be another “grand minimum” of solar activity and that it could lead to significantly colder weather such as gave rise to the frost fairs on the Thames.
This is one of those predictions that are not fun because real lives are at stake. As I said above cold is a real killer, so the precautionary principle says that we should be more cautious of cooler temperature than heat.
But is there any reason to believe this recent cold weather is part of a longer term pattern?
The truth is that we know what could happen, but there is not a lot of evidence or knowledge on what will happen. My current view is that we are not experiencing cold weather that is either significantly colder than expected or particularly longer than expected, but it is worrying that we seem to have had a quite long period with unusually cold weather for the time of year. However, because of the time taken to warm up after cold, the length and depth of cold are not independent.
Personally I am not making any preparation or planning for unusually cold weather at the moment. However, should this period of cold continue for another month or more, or we see short periods of much colder weather, I will need to reconsider that view.
However, if I were involved in services affecting the elderly or other vulnerable groups where the risk of cold is all the higher, I think I would be started to discuss what would be needed to be done if the weather were to turn colder. In other words, it would be prudent to start some initial contingency planning to highlight any week areas which might need addressing if the need arose later on.