No Warming for 16 Years!

The Mail on Line reports:
  • The figures reveal that from the beginning of 1997 until August 2012 there was no discernible rise in aggregate global temperatures
  • This means that the ‘pause’ in global warming has now lasted for about the same time as the previous period when temperatures rose, 1980 to 1996
The regular data collected on global temperature is called Hadcrut 4, as it is jointly issued by the Met Office’s Hadley Centre and Prof Jones’s Climatic Research Unit.
The new data, compiled from more than 3,000 measuring points on land and sea, was issued  quietly on the internet, without any media fanfare, and, until today, it has not been reported. 

This stands in sharp contrast  to the release of the previous  figures six months ago, which went only to the end of 2010 – a very warm year. 

Ending the data then means it is possible to show a slight warming trend since 1997, but 2011 and the first eight months of 2012 were much cooler, and thus this trend is erased. 

Some climate scientists, such as Professor Phil Jones, director of the Climatic Research Unit at the University of East Anglia, last week dismissed the significance of the plateau, saying that 15 or 16 years is too short a period from which to draw conclusions.

Others disagreed. Professor Judith Curry, who is the head of the climate science department at America’s prestigious Georgia Tech university, told The Mail on Sunday that it was clear that the computer models used to predict future warming were ‘deeply flawed’.

Even Prof Jones admitted that he and his colleagues did not understand the impact of ‘natural variability’ – factors such as long-term ocean temperature cycles and changes in the output of the sun. 

Here are three not-so trivial questions you probably won’t find in your next pub quiz. First, how much warmer has the world become since a) 1880 and  b) the beginning of 1997? And what has this got to do with your ever-increasing energy bill?

You may find the answers to the first two surprising. Since 1880, when reliable temperature records began to be kept across most of the globe, the world has warmed by about 0.75 degrees Celsius. 

From the start of 1997 until August 2012, however, figures released last week show the answer is zero: the trend, derived from the aggregate data collected from more than 3,000 worldwide measuring points, has been flat.


There has been a response from the UK Met Office (Link)
Q.1 “First, please confirm that they do indeed reveal no warming trend since 1997.”
The linear trend from August 1997 (in the middle of an exceptionally strong El Nino) to August 2012 (coming at the tail end of a double-dip La Nina) is about 0.03°C/decade, amounting to a temperature increase of 0.05°C over that period...
Q.2 “Second, tell me what this says about the models used by the IPCC and others which have predicted a rise of 0.2 degrees celsius per decade for the 21st century. I accept that there will always be periods when a rising gradient may be interrupted. But this flat period has now gone on for about the same time as the 1980 – 1996 warming.”

The models exhibit large variations in the rate of warming from year to year and over a decade, owing to climate variations such as ENSO, the Atlantic Multi-Decadal Oscillation and Pacific Decadal Oscillation.
Definitely Non Gorgon Judith Curry.
Dr Judith Curry wrote to David Rose (the author of the Daily Mail article): (link)
The data confirms the existence of a ‘pause’ in the warming. The impact of this pause within the climate dynamic community has been to focus increased attention on the impact of natural variability, particularly the impact of internal multi-decadal oscillations in the ocean.  The new climate model calculations for the AR5 have focused on trying to assess what it would take to accurately simulate these multi-decadal ocean oscillations and how predictable they might be.  These new observations and climate modeling results will hopefully impact the the IPCC AR5 deliberations so that we do not see the same overly confident consensus statements that we saw in the AR4.  
And more From Judith Curry: (link)
A note to defenders of the idea that the planet has been warming for the past 16 years:Raise the level of your game.  Nothing in the Met Office’s statement or in Nuticelli’s argument effectively refutes Rose’s argument that there has been no increase in the global average surface temperature for the past 16 years.
Use this as an opportunity to communicate honestly with the public about what we know and what we don’t know about climate change. Take a lesson from these other scientists that acknowledge the ‘pause’, mentioned in my previous post Candid comments from global warming scientists

Meanwhile, Ex IPCC expert (and 0.0001 Nobel Laureate) John Christy has written recently:
The recent claims that July 2012 and Jan-Jul 2012 were the hottest ever in the conterminous US (USA48) are based on one specific way to look at the US temperature data. NOAA, who made the announcement, utilized the mean temperature or TMean (i.e. (TMax + TMin)/2) taken from station records after adjustments for a variety of discontinuities were applied. In other words, the average of the daily high and daily low temperatures is the metric of choice for these kinds of announcements. Unfortunately, TMean is akin to averaging apples and oranges to come up with a rather uninformative fruit.
Finally, a misinformed person has written:
It is very easy to pick one’s own start and stop dates to show that there has been no warming, that there has been cooling or that the warming is twice as fast.

David Whitehouse of the Global Warming Policy Foundation addresses this : (Link)
Finally, it has been said that the 16-year standstill observed in the Hadcrut4 data since 1997 has been cherry-picked with its start and end dates. This is not so, the period is simply the answer to the question how far back does one have to go to see significant warming taking the errors into account. In fact, start and end dates are irrelevant, only its duration is important, not where it occurs in the dataset.


  1. Interesting ... when did 2006 become warmer than 1998?


Post a Comment

All serious comments published after moderation.
Comments should be polite, and respect all views.
No bad language. Spam never makes it!