David Roses latest mash up of Met Office weather and climate research
From last weekend’s weather to climate change over the next few decades, climate skeptic journalist David Rose throws together a few different aspects of the UK’s weather system in an article this weekend – the intended effect of which is apparently to cast doubt on the abilities of the UK’s official forecaster.
In his article in yesterday’s Mail on Sunday, Rose takes us on a whistlestop tour of the Met Office’s research into what’s behind unusual weather in recent years, mixing up many of the already complicated issues as he goes. The result? A bit of a confused mess.
Unique UK weather
Rose’s piece begins with a critical look at the Met Office’s forecast for last weekend, saying the forecaster “wasn’t at all sure how Britain’s weather would turn out [on Sunday].”
To give Rose credit, he points out that the source of the uncertainty was a weather pattern known as a “trough disruption”. Chief Met Office forecaster Nick Grahame explained last week that it’s hard to predict exactly which direction such weather systems will take.
“[T]here’s a low pressure system over the west Atlantic and, on the face of it, appears to be heading our way. However, as it approaches our shores on Saturday night, forecast models are suggesting a large degree of uncertainty in terms of where it goes next.”
This is just one example of the extremely complicated and hard-to-predict weather system we have in the UK. Our weather is determined by many factors – notably the jet stream, a river of fast-flowing air guiding the path of weather systems coming across the Atlantic.
Met Office “emergency meeting”
The Met Office is set to host a meeting this week “to discuss the recent run of unusual seasons here in the UK” – and possible links to climate change.
This year began with an extremely cold and prolonged winter, ending up as the second coldest March since records began in 1910. As if that wasn’t bad enough, it followed a particularly disappointing summer in 2012, which saw the wettest June for over a century.
While the jet stream varies naturally, a big question for scientists is whether climate change is disrupting the normal movement of the jet stream, moving it into positions we wouldn’t normally find it in a particular season.
But the meeting isn’t quite the “emergency summit” some parts of the media, including Rose, are making it out to be.
We spoke to the Met Office when news of the meeting first circulated back in April. The Met Office also released a statement on Friday – before Rose’s article was published – saying “workshops of this kind are held on a regular basis on a great deal of issues across weather and climate science”.
So Rose’s suggestion that the meeting is a rushed attempt to explain the recent run of bad weather is rather misleading.
No single cause
While scientists are making progress in working out how climate change influences the odds of extreme weather, the notoriously unpredictable UK weather means it would be unwise to try to attribute a few years’ events to a single cause.
Stephen Belcher from the Met Office said in the statement on Friday:
“This may be nothing more than a run of natural variability, but there may be other factors impacting our weather.”
And as the Met Office said in response to this year’s very cold spring:
“[Many interlinking factors] can make communicating the science drivers more complicated and nuanced than some audiences may wish. On the other hand, this simply reflects the richness and complexity of our climate system, which drives the weather that we experience on a daily basis.”
UK summers
Turning to the theme of disappointing weather, Rose claims we shouldn’t be surprised by cool summers. Using a graph of summer temperatures from the Central England Temperature Record – which dates back to 1659 – Rose claims cool summers have in fact been the norm for hundreds of years. He says:
“[H]ot golden summers have always been the exception, neither rainfall nor average temperatures have shown much change for several centuries.”
Image - David Rose _summertemperatures (note)
Source: The Mail on Sunday
Despite natural variability causing large fluctuations from year to year, an increase in summer temperatures since about the start of the 20th century is visible in the graph Rose shows.
That trend isn’t as clear as it could be in that graph because of an unhelpfully large temperature scale on the left hand side. But you can see that trend a bit closer up on the Met Office official website here, and below.
Image - Met Office _summer _temp (note)
Source: Met Office
In fact, the Met Office says while the UK is set to get wetter over other seasons, summers are becoming warmer and drier on average due to climate change. According to its official blog:
“In the long term, most climate models project drier UK summers – but it is possible there could be other influences of a changing climate which could override that signal on shorter timescales.”
Mash up
Climate scientists have been speculating about how climate change could influence UK weather long before this year’s cold spell or last year’s rainy summer. But given the UK’s notoriously complicated weather patterns, teasing out how much of what we’re seeing is down to natural variability and how much could be influenced by greenhouse gases is likely to be a tough task. By mashing up the various components of the problem, Rose is only contributing to the confusion.