Archives for January 2011

Global temperature forecast for 2011

Paul Hudson | 17:06 UK time, Wednesday, 26 January 2011

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Last year, according to the Met Office Hadley Centre, was the second warmest on record with a temperature anomaly of 0.50C above the 1961-1990 average.

This was very close, but slightly below their forecast which was issued at the Copenhagen climate summit in December 2009. It stated global temperatures were likely to be almost 0.6C above the 1961-1990 average.

In fact the forecast for 2010 was part of a projection for 2009-2019 which showed a range of possible outcomes for each year but with a "central estimate" for 2010 showing a figure of about 0.55C above the average. The forecast of a 0.6C rise it would seem was 'rounded up' from this central estimate.

This means that in the last 11 years, 10 of the global forecasts issued by the Met Office have been too warm. This 'warm bias' in their forecasts, first discussed on this blog, and later by Roger Harrabin, is very small, just 0.05C, and according to the Met Office the difference between the forecast and the actual temperature is within its own stated margins of error.

But it would be normal to expect a random scatter of errors either side of the central forecast temperature, rather than for the error to be always on the warm side, as is the case here.

There could be a number of explanations for this, including the lack of observations in the Arctic circle where warming has been strong. If this warming has been underestimated, it would mean that the Met Office global forecasts in the last 11 years may not have a warm bias - it could be that global temperatures have been warmer than what has actually been observed.

Looking ahead, The Met Office expects 'half the years between 2010 and 2015 to be hotter than the hottest year on record'.

As for 2011 they are expecting another very warm year, with a global anomaly forecast of +0.44C above the 1961-1990 average.

That would make 2011 the equal 6th warmest year on record. Their latest forecast for 2011 can be read here.

So far, it's been a very cold start to the year globally. With La Nina, an area of cold water in the tropical Pacific which depresses global temperatures, expected to continue well into 2011, the Met Office's global forecast is already beginning to look too warm.

Met Office: 2010 Globally second warmest on record

Paul Hudson | 17:28 UK time, Wednesday, 19 January 2011

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Last week, researchers at NASA's Goddard Institute for Space Studies (GISS) in New York, where temperature records extend back to 1880, announced that global surface temperatures in 2010 tied with 2005 as the warmest on record.

This was similar to data released by National Oceanic and Atmospheric Administration (NOAA) which showed the Earth in 2010 experienced temperatures higher than the 20th century average for the 34th year in a row.

Overall, according to NOAA, 2010 and 2005 were 0.62 Celsius above the 20th century average when taking a combination of land and water surface temperatures across the world.

In an interview with Reuters today, Professor Phil Jones from the Climate Research Unit (CRU) at the University of East Anglia said last year was the world's second hottest behind 1998 in their temperature record going back to 1850.

And data due to be released by the Met Office Hadley Centre tomorrow will also show that 2010 was the second warmest year on record, beaten only by 1998.

The discrepancy between the data sets is thought to be down to the way temperatures are measured across the data sparse Arctic region, where warming has been strong in recent years.

According to the Met Office, this could be because the region is poorly represented in datasets as there are very few observing stations, an issue which the Met Office say they are looking to address.

The other data set, based solely on satellite data and compiled by the University of Alabama (UAH), and released at the start of January, also shows 2010 was the second warmest year on record, beaten only by 1998 - but by a fraction and in statistical terms the difference between the two years is insignificant.

Following El Nino, an area of warm water in the tropical Pacific, which helped lift global temperatures to elevated levels in 2010, its sister La Nina, an area of cold water in the Tropical Pacific, is doing the exact opposite and causing Global temperatures to fall quite sharply.

The figure below shows the Japanese computer models' forecast for sea surface temperature anomalies for the period March 2011 to May 2011, with La Nina clearly still visible in the tropics, continuing to have a cooling influence on Global temperatures.



With most forecasts showing that La Nina could last for much of 2011, it seems likely that 2011 will be much cooler than 2010

The Met Office DID forecast a cold winter.

Paul Hudson | 16:55 UK time, Wednesday, 12 January 2011

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There's been much in the news over the last week or so, regarding the issue of whether or not the Met Office did forecast a cold winter, and if so was this communicated to the government. You can read one version of events in the Independent newspaper by clicking here.

Readers of this blog will know that on October 1st last year I wrote an article, called 'Another cold winter ahead?' which you can read by clicking here.

In it I commented 'The Met Office don't issue their seasonal forecast to the general public anymore, using them for internal research purposes only, but as I understand it, their forecast also suggests that the probability of a cold winter is higher than normal.'

On the 5th October I followed up this article with an update that you can read by clicking here.

In it I say 'Having seen computer model output from the 3 main centres - the Met Office, the European Centre for Medium Range Forecasting (ECMWF) and the American centre (NCEP) - the conclusion is that this winter is likely on average to be dominated by High pressure, with below average rainfall and temperatures colder than average. Moreover a mild and wet winter, with West or Southwest winds, which have been such a feature of our climate for much of the last 20 years, again seems unlikely.'

The colour map below shows the actual forecast that I obtained at the time and wrote about. It's a Met Office winter temperature profile, and there can be no doubt that it does show that the UK and Europe could expect a cold winter.



This should put an end to the ongoing discussion as to whether the Met Office forecasted a cold winter or not.

It is worth stressing that this is an average temperature profile across winter - December, January and February. It suggests that the winter would be cold, but it doesn't by definition give any clue as to the severity of the weather that we experienced in December - nor would it since seasonal forecasts are just that - an average for the season

Coal takes the strain...again.

Paul Hudson | 16:44 UK time, Monday, 10 January 2011

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On BBC Look North on friday I reported that during the recent intense cold weather, it's been our traditional coal and gas fired power stations that have been working flat out to keep our homes and businesses warm.

And for the third winter running, the intense cold has gone hand in hand with periods of little or no wind. This should come as no surprise since prolonged cold is invariably associated with areas of high pressure.

Peak demand also comes during summer heat waves - as we all turn on our air conditioning units - again usually associated with areas of high pressure, with little or no wind.

December 21st 2010 was one of the coldest days on record in Yorkshire. The bar chart below gives an idea of how much electricity was being generated by which type of power facility, when temperatures were at their lowest.



With much of the country experiencing very little wind, both onshore and offshore, wind turbines were largely inactive.

At the moment that is not a problem. Only 5% of electricity is currently generated by wind farms, and so other power stations can step in and ramp up output.

But in only 9 years time, the UK will legally have to generate around 30% of its electricity from renewable sources, of which 25% is expected to come from wind farms alone, as it is seen as a clean, carbon free energy source.

So what will happen then, when the wind doesn't blow?

If a similar meteorological situation occurred in 2020, then almost 25% of power would have to come from sources other than wind.

This means that there would have to be some power stations - using coal or gas, since nuclear power output can't be increased at short notice - that simply exist as a stand-by facility, in case the wind doesn't blow.

And that's a very expensive way of producing electricity.

And what happens if, as seems at least possible, the next 10-15 years sees an increase in the type of disrupted weather patterns that we have experienced recently, because of solar considerations?

Professor Mike Lockwood at Reading University thinks that the UK could indeed experience colder winters on average, compared with the last few decades because of the sun's low activity.

This would lead to a higher frequency of 'blocking' weather patterns leading to less frequent windy conditions than would normally be expected if one looks at climatological averages - suggesting we would have to continue to rely on coal and gas fired power generation well into the future - and possibly more than is currently envisaged.

December 2010 update: Second coldest since 1659

Paul Hudson | 16:54 UK time, Tuesday, 4 January 2011

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Met Office provisional figures show that December 2010 with a mean CET temperature of -0.7C was the second coldest since records began in 1659, beaten only by December 1890 which had a mean of -0.8C.

The diagram below shows how the month ranks with other cold Decembers, a truly memorable month climatologically.



December 2010 was also easily the coldest December based on CET minimum temperature data which started in 1878.

December was Leeming's coldest month since records began in 1945. The mean was -1.75C compared to the previous coldest month of February 1963 with a recorded mean of -1.4C.

December 2010 was also a new record for minimum temperatures at Leeming for any month since records began in 1945, with a mean minimum temperature of -5.3C, illustrated below with comparison to the winter months of 1962/1963 - which turned out to be the coldest winter of the last century.


First global temperature data published: 1998 still hottest year - by a whisker.

Paul Hudson | 20:32 UK time, Monday, 3 January 2011

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The first eagerly awaited data on 2010 global temperatures shows that although it was a very close run thing, 2010 has failed to beat 1998 which still holds the title of hottest year on record.

The UAH global temperature satellite data, recorded and compiled by the University of Alabama in the USA, started in the late 1970's. It is worth stressing though that statistically speaking, within the stated margin of error, there is no difference between 2010 and 1998.

Nonetheless the headline figure of 1998 (+0.424C) is higher than 2010 (0.411C). Please note that these UAH temperature anomalies are now relative to the 1981-2010 average.

You can read more on this by clicking here.

Other data sets, namely NOAA, (NASA) GISS, and the Met Office's HADCRUT will be published later this month.

Of interest may be an article I wrote on the 12 last December called 'Global temperature predictions for a new decade' which you can read by clicking here.

Global temperatures are finally responding to cooler ocean temperatures, in particular La Nina in the tropical pacific, with cooling also seen in the Northern Hemisphere

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