Friday, 1 November 2013

A Reaction to Mike Lockwood's Carbon Brief blog post 1/11/13

Professor Mike Lockwood has written more formally on the controversy which has blown up around his decision to speak to Paul Hudson about his research into solar activity. You can view it here.

He concentrates his fire exclusively on the Express now for misquoting him, although, quite frankly, I can't see how they have transgressed by merely reporting on what he said in his interview with Hudson on the BBC. He says:

"Unfortunately, I now find myself in the position of being cited as predicting that the current rapid decline in solar activity will plunge the world into a "Little Ice Age".

There is not one single mention in the Express article about global cooling; it is all about Britain, Europe, the UK. Where does Lockwood get the notion that the Express is warning of the world being plunged into a new 'Little Ice Age'? Perhaps the Express amended the news item, though it is still dated 28/10/13.

More to the point, Lockwood's comments on the Maunder Minimum, Little Ice Age and Central England Temperature give cause for concern. He states categorically that:
"There is some evidence for a prolonged period of somewhat lower global mean temperatures beginning in around 1400 to 1500 (estimates vary) and ending sometime between 1700 and 1800. 
This has been termed the " Little Ice Age" and is often wrongly linked with the Maunder minimum in solar activity, a period between about 1650 and 1700 when almost no sunspots were seen."

Apparently then, he sees absolutely no reason to suggest that the Maunder Minimum caused, wholly or partly, the dramatic drop in European temperatures concurrent with the decrease in solar activity at that time, even though there is a strong positive correlation between the two. I say 'apparently' because Lockwood's " Little Ice Age" seems to be slightly different from the traditional notion of what most would term the Little Ice Age, a predominantly European phenomenon. Whatever, he seems to be tying himself up in knots by acknowledging a global LIA effect, denying that it is solar-induced, then saying elsewhere that there is a possibility that solar activity affects UK and European climate. Finally, is it purely coincidental that the worst winters on average experienced in the UK occurred precisely between the years during which solar activity reached its absolute minimum in terms of sunspot numbers, i.e. 1645-1715?

As just mentioned, whilst acknowledging that the world did indeed see lower global temperatures between about 1400 and 1800, Lockwood does not accept the fact that the Sun was a major contributing cause to this drop in temperature, preferring instead to finger the blame on volcanoes and internal climate variability.

Quoting Lockwood again:

"During the Maunder minimum there were an unusually large number of cold winters in Europe. However, there is no evidence that this was a global phenomenon. Indeed, our research strongly suggests it was a regional phenomenon and that the colder winters in Europe would have been accompanied by warmer ones elsewhere, for example Greenland."

He's already acknowledged lower mean global temperatures during the Maunder Minimum, so what exactly is Lockwood saying here? It appears to be self-contradictory. Is he just implying that there is no evidence for lower winter temperatures on a global scale? Seems odd, if there is evidence for lower mean global temperatures?!

Lockwood seems to have issues with the term 'Little Ice Age' anyway, because he thinks that it implies that Europe was plunged into unrelentingly glacial cold conditions during this period. I don't think many sensible people think that; that's why it's called 'Little' because it wasn't an ice age really, just seemed like it over many bitter winters. He points out that the coldest winter in the depths of the Maunder was followed two years later by one of the warmest in the CET record. Yes, it was, but this does not detract from the fact that the majority of winters during this period were bitterly cold. Most people reasonably aware of climatology and European history will be aware of this fact. That is why we say the climate of Europe changed during this period.

His final dig at LIA terminology involves saying that,

" . . . there's no evidence that summers in the Maunder minimum were any colder than usual. This is not a "Little Ice Age" - it is not an ice age of any shape or form."

This is very odd coming from a distinguished Professor of climate science. Is it just my eyes then that see a definite trend in this graphic of the five year running CET average for summers?

Lockwood continues his blog post by affirming that there is a possible link between European winter temperatures and solar activity, stressing that this is purely regional and there is very little possibility of a new Maunder minimum affecting temperatures globally, even though he earlier stated that the Maunder Minimum was evinced by a drop in mean global temperatures, even though he earlier denied that there was an association between the Maunder Minimum and the LIA. All very confusing to the average layperson!