Jan 222008

I posted (here) about the rather strange way that the Met Office uses reference periods when it announces record breaking weather events. As New Year is the time when they make their annual global temperature forecast for the next twelve months, I thought that it would be worth looking at what they predicted for 2007, and then what they are predicting for 2008.

Here’s the Met Office’s first press release of 2007 issued last January:

4 January 2007

2007 – forecast to be the warmest year yet

2007 is likely to be the warmest year on record globally, beating the current record set in 1998, say climate-change experts at the Met Office.

Each January the Met Office, in conjunction with the University of East Anglia, issues a forecast of the global surface temperature for the coming year. The forecast takes into account known contributing factors, such as solar effects, El Niño, greenhouse gases concentrations and other multi-decadal influences. Over the previous seven years, the Met Office forecast of annual global temperature has proved remarkably accurate, with a mean forecast error size of just 0.06 °C.

Met Office global forecast for 2007

  • Global temperature for 2007 is expected to be 0.54 °C above the long-term (1961-1990) average of 14.0 °C;
  • There is a 60% probability that 2007 will be as warm or warmer than the current warmest year (1998 was +0.52 °C above the long-term 1961-1990 average).

The potential for a record 2007 arises partly from a moderate-strength El Niño already established in the Pacific, which is expected to persist through the first few months of 2007. The lag between El Niño and the full global surface temperature response means that the warming effect of El Niño is extended and therefore has a greater influence the global temperatures during the year.

Katie Hopkins from Met Office Consulting said: “This new information represents another warning that climate change is happening around the world. Our work in the climate change consultancy team applies Met Office research to help businesses mitigate against risk and adapt at a strategic level for success in the new environment.”

The reference to El Niño is important. These periodic and unpredictable convulsions in the Pacific Ocean’s surface temperatures can have a dramatic effect on climate across much of the world. A major El Niño event was partly responsible for the very high global temperatures of 1998. In fact about a third of the temperature anomaly that made that year the warmest recorded for the 20th century can be attributed to this effect. So the Met Office is relying on a perfectly natural, but unpredictable event to boost global temperatures towards a new record. But the problems with predictions, particularly if you base them on phenomena that are not well understood, is that things can go very badly wrong.

By the beginning of February the ‘moderate-strength El Niño already established in the Pacific, which is expected to persist through the first few months of 2007’, had died. But worse was to come when a La Niña event set in. This phenomena is El Niño’s cold sister, and it has the opposite effect to El Niño, causing cooling on the same scale. One might expect that the Met Office would issue a press release revising their forecast, which was now likely to be very wide of the mark, but they did no such thing. Indeed it would have been very embarrassing to do so, given the wide media coverage that their ‘2007 – forcast to be the warmest year yet’ headline had received. This is a pity, because many people must have been mislead into thinking that 2007 would provide more evidence of a climate catastrophe. This impression was reinforced by Katie Hopkins claim that ‘This new information represents another warning that climate change is happening around the world’. Presumably Ms Hopkins is not a scientist, or she would know that ‘information’ is defined as facts provided or learned about something. Predictions are not facts, although it is becoming increasingly common in climate science to to treat them as if they are. This distortion of the scientific method, which seems to be associated with arrogant overconfidence, is almost certain to lead to erroneous conclusions.

June 2007 brought a meeting of the G8 at which global warming featured prominently. To celebrate this event the Met Office issued a press release that went some way towards coming clean about their obviously compromised January forecast. But this was done in such a way that they could be quite sure that the media would focus their attention on spicier morsels included in the text.

5 June 2007

Climate figures revealed as G8 leaders prepare to meet

As G8 leaders meet in Germany this week to discuss global issues such as climate change, the Met Office has revealed figures showing that the mean global temperature for the period January to April was almost 0.5 °C above the long-term average.

The Met Office global temperature forecast predicted that 2007 had a 60% probability of being the warmest on record, with a mean temperature 0.54 °C above the long-term (1961-1990) average of 14 °C.

David Parker, a climate variability scientist at the Met Office Hadley Centre said: “These latest Met Office figures show that the first four months of 2007 are on track with our global forecast for a warmer-than-average year, but the cool La Nina event developing in the equatorial Pacific could prevent 2007 from being the warmest ever year”.

Met Office figures also reveal that this spring has been the warmest since UK-wide records began in 1914. The UK mean temperature for Spring 2007 was 9.0 °C, beating the previous record of 8.8 °C set in 1945. The three spring months of March, April and May all exceeded their long-term average temperatures.

The warm UK spring follows one of the warmest recorded winters, and a run of record breaking years – the last five years are the warmest on record – and this warming trend is consistent with our predictions from the Met Office Hadley Centre.

The Met Office works with government and other organisations by offering advice on the possible consequences and risks of climate change.

Needless to say the media dutifully trumpeted the warmth of the first four months of the year, during which the now defunct El Niño might still have had some influence.

So lets spare the Met Office’s blushes, and fast forward to mid-December 2007 and see how things are going. At this time a press release was cunningly timed to coincide with the end of the UN’s Bali climate change conference when headlines worldwide were about global warming.

Another warm year as Bali conference ends

13 December 2007

The Met Office Hadley Centre and the University of East Anglia have today released preliminary global temperature figures for 2007, which show that the top 11 warmest years all occur in the last 13 years.

The provisional global figure, using data from January to November, currently places 2007 as the seventh warmest on record since 1850.

The announcement comes as the Secretary-General of the World Meteorological Organization (WMO), Michel Jarraud, speaks at the Conference of the Parties (COP) in Bali.

Scientists and politicians have been in Indonesia discussing plans to reduce greenhouse gas emissions that have been linked to increasing global temperatures.

Dr Vicky Pope from the Met Office Hadley Centre, who has been attending the conference said, “The last few days have provided an important platform for debate and confirms the need for swift action to combat further rises in global temperatures because of human behaviour.”

The last time annual mean global temperatures were below the 1961-1990 long-term average was in 1985. Since then, mean surface air temperatures have continued to demonstrate a warming trend around the world. 2007 has been no exception to this, even though there has been a La Niña event which usually reduces global temperatures.

Professor Phil Jones, Director of UEA’s Climatic Research Unit, said, “The year began with a weak El Niño – the warmer relation of La Niña – and global temperatures well above the long-term average. However, since the end of April the La Niña event has taken some of the heat out of what could have been an even warmer year.”

In January the Met Office, in conjunction with the University of East Anglia, predicted that 2007 could record global temperatures well above the long-term average. There was also a 60% probability that 2007 could be the warmest on record and the expected temperature for 2007 is within the range predicted.

Professor Jones said, “2007 was warmer in the Northern Hemisphere, where the year ranks second warmest, than the Southern Hemisphere, where it ranks ninth warmest.”

Met Office Climate Scientist David Parker added, “This year has also seen sea-ice extent in the Northern Hemisphere below average in each month of 2007, with record minima sea-ice reported in July, August and September. In the Southern Hemisphere, sea-ice coverage has remained close to average.”

Meanwhile, across the UK, 2007 is on course to become one of the warmest years on record. Even if the mean temperature for December is 1 °C below the 1971-2000 long-term average, the year will still be the third warmest since UK-wide records began in 1914. In this 94-year series, the last six years (2002-2007) are set to become the six warmest years.
150 years’ temperatures
Chart showing yearly ranking of years from 1961-07 temperature anomalies
Source: Met Office Hadley Centre and UEA Climatic Research Unit

There is a saying among statisticians that if you torture the data for long enough they will tell you whatever you want to hear. Among the yells and screams in this press release – ‘top 11 warmest years all occur in the last 13 years’, ‘surface air temperatures have continued to demonstrate a warming trend around the world’, ‘2007 was warmer in the Northern Hemisphere’, ‘across the UK, 2007 is on course to become one of the warmest years on record’ – the fact that the Met Office’s prediction could hardly have been more inaccurate could easily pass unnoticed. Yet an organisation with this kind of record for short term predictions is taken seriously by the Govenment and the IPCC when its general circulation models predict global average temperatures fifty or a hundred years ahead. Perhaps, in the present political climate, a large organisation that makes a serious mistake can be expected to try and spin its way out of trouble. What is quite unforgivable is a blatant attempt to conceal the fact that global average temperatures are now falling among a welter of carefully selected data that is intended to convey the opposite.

Of course the year was not yet over when this was published, although there were certainly sufficient data available to show that 2007 had fallen from favorite in the warmest year stakes to become an also ran at very long odds. If these figures are confirmed (and I will update this post as soon as I see them) then the downward trend now clearly visible on temperature graphs is likely to accelerate. Will the Met Office issue a clear and objective press release about this if they do? It seems very unlikely on present form, which is surprising given that scientists are supposed to be dedicated seekers after the truth and not purveyors of propaganda.

So what about the January 2008 prediction for global temperatures

Global temperature 2008: Another top-ten year

3 January 2008

2008 is set to be cooler globally than recent years say Met Office and University of East Anglia climate scientists, but is still forecast to be one of the top-ten warmest years.

Each January the Met Office, in conjunction with the University of East Anglia, issues a forecast of the global surface temperature for the coming year. The forecast takes into account known contributing factors, such as El Niño and La Niña, increasing greenhouse gas concentrations, the cooling influences of industrial aerosol particles, solar effects and natural variations of the oceans.
Met Office forecast for global temperature for 2008

Global temperature for 2008 is expected to be 0.37 °C above the long-term (1961-1990) average of 14.0 °C, the coolest year since 2000, when the value was 0.24 °C.

For 2008, the development of a strong La Niña in the tropical Pacific Ocean will limit the warming trend of the global climate. During La Niña, cold waters upwell to cool large areas of the ocean and land surface temperatures. The forecast includes for the first time a new decadal forecast using a climate model. This indicates that the current La Niña event will weaken only slowly through 2008, disappearing by the end of the year.

Prof. Chris Folland from the Met Office Hadley Centre said: “Phenomena such as El Niño and La Niña have a significant influence on global surface temperature and the current strong La Niña will act to limit temperatures in 2008. However, mean temperature is still expected to be significantly warmer than in 2000, when a similar strength La Niña pegged temperatures to 0.24 °C above the 1961-90 average. Sharply renewed warming is likely once La Niña declines.”

These cyclical influences can mask underlying warming trends with Prof. Phil Jones, Director of the Climatic Research Unit, University of East Anglia, saying: “The fact that 2008 is forecast to be cooler than any of the last seven years (and that 2007 did not break the record warmth set on 1998) does not mean that global warming has gone away. What matters is the underlying rate of warming – the period 2001-2007 with an average of 0.44 °C above the 1961-90 average was 0.21 °C warmer than corresponding values for the period 1991-2000.”

Whatever Professor Jones may say, if the prediction for 2008 is even approximately right, we will go into 2009 with temperature charts that look very different to the ones that we are seeing at the moment (see graph here). What will the Met Office say if there is an accelerating downward trend? There is something rather celebratory about ‘Another top-ten year’, like a marketing director reporting on last year’s excellent sales figures. But would he refer to projected sales for next year with quite the same degree of certainty, or is this degree of confidence confined to scientists who use super computers to make predictions about the climate?

‘Global Temperature 2008: Another top-ten year’, suggests that there may be some confusion at the Met Office between predictions and facts. The headline for the 2007 prediction includes the word ‘forecast’, why does the 2008 prediction not do so?

All Met Office press releases referred to can be found here .

UPDATE 05/02/2006: Apparently Katie Hopkins (quoted above) was sacked in June from her £90,000 pa post as a ‘brand consultant’ with the Met Office for ‘bringing weather forecasters into disrepute’. It would be reassuring to think that this was because of the heavily hyped press releases about climate change that this once respectable scientific organisation has been putting out, but it would seem that exaggeration was not an issue. The reason for Ms Hopkins’ downfall was quite different, and may explain her obvious enthusiastiasm about the imminent onset of global warming, (see here).

On a more serious note, it is worth pondering why the Met Office is paying a large salary to someone to promote it activities as a ‘brand’, and what implications this has for the way in which they publicise scientific research when PR and marketing strategies are so obviously a priority for them. It is hard to think of a better way to keep your organisation in the public eye than making catastrophic predictions that seem to be backed up by authoritative scientific evidence.

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