Sunday, 21 June 2009

Yeovilton and Climate Change

James Barlow has provided a link on his blog to figures provided by the UK Met Office from their network of weather stations; it includes temperature data collected since Sept 1964 from a weather station in or near Royal Naval Air Station Yeovilton (which is also host to the Fleet Air Arm Museum, destination for more than one childhood day trips). James has helpfully plotted the maximum and minimum temperatures in degrees centigrade for each year onto a graph:

I imagine that for many, glancing at the figures shown above, their first thoughts might be "hold on, where's the evidence of this global warming we keep being told is happening?"

It's a perfectly reasonable question. To try and answer it we first need to recognise that global warming is the result of a long-term change in climate, evidence of which can often be subsumed within the short-term variations in the weather. For example, anybody living in Britain knows that just because it is warm and sunny in the morning does not guarantee that it will not be several degrees colder and pouring with rain in the afternoon - this is because we live in a temperate country with a maritime climate that is on the boundary between competing climate systems leading to wide fluctuations in our weather. Because of these fluctuations we can get events like the long hot summer of 1976 with less than 90mm of rain from the beginning of April until the end of August, but this "freak" summer did not guarantee a long hot summer of 1977 (which in fact showered us with nearly 290mm of rain over the same months). Freak weather events are deviations from the climate norm - so for example, Britain's worst ever natural disaster was caused on the night of 31st January 1953 by a "freak" storm that caused flooding in the east of England leading to 24,000 homes being flooded and the death of 300 people in the UK (another 1,800 died in the Netherlands). The storm was said to be a once in every 250 years event.

Extreme "freak" variations from the climate norm can be devastating enough but if there is a steady long-term change in the underlying climate those type of events can move from being "freak" events to becoming "frequent" events and even the norm themselves. The 1953 "once in every 250 years" is forecast to become "once in every 12 years" and a report by the UK Office of Science and Technology predicts that the current situation which sees £2.2 billion spent on coastal defenses and flooding damages may see a rise to £27 billion/year by 2080 because of the impact of changes to the UK climate if the UK's underlying climate is increasing in temperature.

So let's look at the graph again, but this time we will add a trend line to see if there is an underlying trend in the temperatures;

We can now see a trend showing an almost imperceptible rise in the underlying temperature. To make this clearer let's look more closely at the maximum temperature graph with the same linear trendline:

We can now see a trend showing an underlying rise in the recorded maximum temperatures of over 1 degree centigrade. In reality, this graph over-eggs the pudding because, as Chris Hutt points out on James Barlow's blog, to get a clearer idea of temperature changes we need to look at changes in average temperatures not maximum and/or minimums and, of course, we need to look at a lot more data than that provided from just one monitoring station in deepest Somerset. Based on data which includes that collected by the UK Met Office, research has shown that over the last century or so, global average temperatures rose by about 0.35 degrees Centigrade until the 1940s, then there was a slight cooling period with a 0.1 degree drop and then since about 1970 temperatures have risen again by 0.55 degrees. All in all, average temperatures have risen by 0.8 degrees Centigrade over the past hundred years.

The UK Met Office are concerned about this and their own figures have made major contributions to the reports produced by the IPCC and the Stern Review and they are closely involved in work on the UK Climate Projections 2009. Below is yet another graph, from the Met Office site, showing the expected rise in temperature based on current projections;

In the summer of 2003, my family and I flew out to the Canary Islands for a holiday. As we headed south just off the Portuguese coast, my daughter pointed out that the sky was virtually cloudless except for "those grey clouds near the ground". Those "grey clouds" were in fact the smoke from forest fires as nearly a 1,000 square miles of Portugal were being burnt to the ground causing $1.5 billion of damage and leading to the deaths of 18. At the same time major rivers like the Po, the Rhine and the Loire were hitting record low levels leading to water shortages for hydroelectricity plants and for irrigation schemes. Crop losses across Europe were estimated at a value of $12 billion. Alpine permafrost melted causing devastating rockfalls whilst glaciers saw their melt rate double with some losing 10% of their total mass in just this one summer. Worse of all, as the heatwave continued, between 22,000 and 35,000 people died from causes attributable to the heatwave, including heat exposure. This was the "freak" European summer of 2003, said to be a 1-in-7,000 year event.

Another freak weather event? - Except that this was caused by an increase in European average temperatures for that year of just 2.3 degrees Centigrade above the norm. What happens when, as the temperature data from Yeovilton is telling us, the norm increases by 2.3 degrees and more?

When will otherwise intelligent people realise that to simply carry on hoping (contrary to all the evidence that experts like those at the UK Met Office are providing us with) that climate change is some sort of scare story made up by environmentalists to give people nightmares is reducing our chances of being able to prevent the worst case scenarios, and, in the final analysis, save people's lives? Just because we don't like it (and believe me, I really wish global warming wasn't happening) won't make it go away. We need to take appropriate actions to reduce the amount of greenhouse gases being pumped into the atmosphere, not try to pretend that we know better then the overwhelming majority of scientists with up-to-date experience in the relevant subject areas.

If a doctor tells you that you have got cancer, you don't ask for a second opinion from a politician - because the politician is more likely to tell you what you want to hear, instead of what you need to know.


  1. Your comments widget doesn't like my HTML links. I've added a response to your thoughts at the end of the original article.–-south-west-uk

  2. Excellent, well researched post. You'll give James a run for his money. I'm glad someone is up to matching his diligence in producing evidence.

  3. PS so those catastrophic weather conditions in 2003 were down to you flying to the Canaries? No wonder you're feeling contrite about climate change.

  4. Mea Culpa

    I dread to think how many cycling trips from Chipping Sodbury to Bristol city centre it is going to take to offset all that carbon.

    Where's a quaestore when you need one?