With this new prediction by the met office Hadley centre shows temperature decrease in the next few years, and then a 50% probability each year of another 1998 record high (which we now know 1934 is actually the highest point, not 1998). Not surprisingly that this new dip in amospheric temperature co-incides with a decrease in solar activity. The theory of AGW is crumbling around their ears!
Over the 10-year period as a whole, climate continues to warm and 2014 is likely to be 0.3 deg C warmer than 2004.
The overall trend in warming is driven by greenhouse gas emissions but this warming effect will be broadly cancelled out over the next few years by the changing patterns of the ocean temperatures."
1) The model does not show a cooling - it shows a reduced rate of warming. i.e. if a rate of increase of some factor were 5 10 15 20 25 30 35 40
a reduced rate might be 5 8 11 14 17 20 23 26
which would not be the same as a drop 5 0 -5 -10 -15 -20 -25 etc
2) This is the first such model - it has been tested against the past (hindcast). But I'm waiting to see how good it is (hopefully it'll be on the ball). For most mitigation efforts decadal changes are crucial because we tend to plan factors that effect society on that sort of timescale. And if this new type of model does prove useful we can act with more certainty over decades than we can on projections over a century (which by definition are not great for the short term).
"2014 is likely to be 0.3 deg C warmer than 2004" implies a warming of 0.3degC/decade. I thought we currently expect the warming of 0.2degC/decade to continue for the next few decades.
I can't find a free link to this - if I do I'll post.
Originally posted by M Batchelor: With this new prediction by the met office Hadley centre shows temperature decrease in the next few years, and then a 50% probability each year of another 1998 record high (which we now know 1934 is actually the highest point, not 1998). Not surprisingly that this new dip in amospheric temperature co-incides with a decrease in solar activity. The theory of AGW is crumbling around their ears!
The only thing clumbling is your information. The 1934 figure only applies to the US, 2005 is still the warmest years for the globe.
The 1934 figure only applies to the US, 2005 is still the warmest years for the globe.
However, the Daily Telegrpah reported that 1998 was "the warmest year on record".
The Daily Telegraph took this in turn from the original article in latest issue of the Journal Science.
"CLIMATE CHANGE: Humans and Nature Duel Over the Next Decade's Climate Richard A. Kerr
Rising greenhouse gases are changing global climate, but during the next few decades natural climate variations will have a say as well, so researchers are scrambling to factor them in...
Anticipating nature Appreciating the power and reach of natural climate variations is a major step. To put that information to use, however, climate forecasters must find a way to model the future course of the variations themselves, starting from current conditions. Climate researchers from the Hadley Centre, led by Douglas Smith, are the first to try that, as they report on page 796.
The Hadley group tested the usefulness of their new prediction model by "hindcasting" the climate of two past decades. Starting from the observed distribution of ocean heat content, the model outperformed its own forecasts that lacked observed initial conditions. Errors in predicting global temperature declined by 20% or 36%, depending on the type of error. The model successfully predicted the warming of El Niño and the effect of unusually warm or cold waters around the world. An actual forecast starting in June 2005 correctly predicted that natural variability--the appearance of cooler water in the tropical Pacific and a resistance to warming in the Southern Ocean--would offset greenhouse warming until now. But beyond 2008, warming sets in with a vengeance. "At least half of the 5 years after 2009 are predicted to be warmer than 1998, the warmest year currently on record," the Hadley Centre group writes.
"Smith et al. is an important first step in setting out the method," says meteorologist Tim Palmer of the European Centre for Medium-Range Weather Forecasts in Reading, U.K. Now researchers need to amass more computing power, more past observations to test the method better, and more future observations to feed the models, he says. And time is of the essence. If the AMO in fact played a substantial role in the rapid warming and enhanced hurricane activity of the past decade or two, says Sutton, "there will in all probability be a turnaround [of the AMO], possibly in the next decade." It would be nice to know for sure.
QUOTE In the global mean, 2005 remains the warmest (as in the NCDC analysis). CRU has 1998 as the warmest year but there are differences in methodology, particularly concerning the Arctic (extrapolated in GISTEMP, not included in CRU) which is a big part of recent global warmth. UNQUOTE
Too close to call! Ye pays yer money and takes yer chance! ie. a statistical tie if anything.
QUOTE In the global mean, 2005 remains the warmest (as in the NCDC analysis). CRU has 1998 as the warmest year but there are differences in methodology, particularly concerning the Arctic (extrapolated in GISTEMP, not included in CRU) which is a big part of recent global warmth. UNQUOTE
Too close to call! Ye pays yer money and takes yer chance! ie. a statistical tie if anything.
And both 1998 and 2005 can be considered outliers. If we do so then 2002 is the peak of the rising trend.Afterwards, there is a gentle decline downwards from 2003 to 2006.
And have a look here at the original graph from Science showing global atmospheric temperature and how much this devistes from old and new models. If anything it shows that the global warming effect is clearly on the wane since the lofty heights of 1998.
Originally posted by M Batchelor: If anything it shows that the global warming effect is clearly on the wane since the lofty heights of 1998.
I'd love to think it's tending plateau out. Have a look at this 25 yr graph. The 150 yr shows a steeper trend but given that CO2 will carry on its merry way up temperatures will sadly follow.
Can someone please explain exactly what is the "temperature anomaly" on the y-axis of these graphs? Does it indicate the year by year change in average temperature, rather than an absolute value? If so, what's the benchmark?
Take your whole dataset, then establish an average from it. You could average the whole dataset or just a part.
Then you display the dataset, such as temperature as difference from the mean.
Take this GISS graph. In 1995 the average temperature was 0.4degC above the 1951-1980 mean (virtually all data uses a recent average period of 30 years).
In other words they take the average of all the yearly average temperatures from 1951 to 1980 then they subtract that figure from the yearly average for 1995, the result is 0.4, that's plotted as an "anomaly" on the graph.
The red trace is a 5 year mean centred on the year in question, processed as above. ie. (T(-2) + T(-1) + T(0) + T(1) + T(2))/5
where for example T(-2) "the current year offset by -2", will be 1990 for the year 1992, and 1992 is T(0) or "the current year offset by 0". You can see that the last figure for the graph is 1994. That's because in 1995 T(2) is 1997, and we haven't yet got the data for 1997.
Originally posted by M Batchelor: If anything it shows that the global warming effect is clearly on the wane since the lofty heights of 1998.
I'd love to think it's tending plateau out. Have a look at this 25 yr graph. The 150 yr shows a steeper trend but given that CO2 will carry on its merry way up temperatures will sadly follow.
I'll have source of your graph though. See if there's any much needed good news on the GW front.
GISS (which shows no tapering) use a grid box method. They map the Earth out into boxed areas and use a method to work out the average temperature of each box.
CRU (shows tapering) uses a hemispheric method, they take the average of stations in each hemisphere, get an average for each hemispheric and combine the the 2 by averaging again. The problems with this are 2 fold:
1) The Southern Hemisphere(SH) has fewer stations then the Northern hemisphere(NH). 2) The SH has much more ocean than the NH. And that ocean damps temperature changes because of both circulation (doesn't happen in the land surface), and water's high specific heat content.
These 2 facts seem to me to combine unfortunately to mean CRU's graph is handicapped by what is in effect an artefact of processing. CRU is over affected by the lag in warming of the Southern Hemisphere and fails to convey the full warming of the NH.
So, aside from the fact that GISS are a habit from my old sceptic days. I consider GISS as closer to the reality than CRU.
Crucial reading on this issue is "An intercomparison of trends in surface air temperature analyses at the global, hemispheric, and grid-box scale." Vose, Wuertz,Peterson. GEOPHYSICAL RESEARCH LETTERS, VOL. 32, L18718, doi:10.1029/2005GL023502, 2005 Sorry but the Moderators have twice removed my link to a free copy of that paper. If you do get a copy then figure 2 is interesting, it shows, GISS, CRU and GHCN's station data processed and presented with all three following the same track, same trend, no tapering.
By the way, climate is deemed by the World Meteorological Oranisation as a period of 30 years (There's stats behind that, but I don't have the details). So going from year to year is fruitless. You need to at least work on a 5 year average.
I'd love to think it's tending plateau out. Have a look at this 25 yr graph. The 150 yr shows a steeper trend but given that CO2 will carry on its merry way up temperatures will sadly follow.
However, the yearly average trend on your graph from Wikipedia is currently downward.
How can people continue to believe that there is a direct proportional link between human-produced CO2 and global temperature? Clearly the data suggest that there is not a straight-forward relationship between the two - nor how significant that relationship is compared to other factors.
[However, the yearly average trend on your graph from Wikipedia is currently downward.]
That’s a bit desperate. By that logic from “my” graph it was downward in 1982, 1984, 1989, 1996, 1999 and 2004. So I wouln’t worry too much about such a short timescale considering there’s 0.5 degrees Centigrade “in the pipeline”. e.g.
“One implication of this imbalance is that, even if atmospheric composition does not change further, the Earth's surface will eventually warm another 0.4–0.7 °C”
The underlying trend is up.
Thanks cobblyworlds for the 30 years but I just had to confirm myself so the following link from New Zealand is a glossary:
“Climate The "average weather", over a period of time ranging from months to thousands or millions of years. The classical period for calculating a "climate normal" is 30 years.”
“Thirty years was chosen as a period long enough to eliminate year-to-year variations.”
Pielke senior uses some other definition but I couldn’t see a simple number like a time period so I’ve ignored it.
[How can people continue to believe that there is a direct proportional link between human-produced CO2 and global temperature? Clearly the data suggest that there is not a straight-forward relationship between the two - nor how significant that relationship is compared to other factors.]
Oops. Seems we’ve morphed to the old contrarian argument of “uncertainties in science”. Not straightforward in climatology? You got that right. Discerning human influence is extremely difficult but the basic physics of GW gases has stood the test of time (> 30 years) and observed changes (right now) are clear enough.
Try the following link for a history of CO2 versus the world’s climate.
“It is likely that increases in greenhouse gas concentrations alone would have caused more warming than observed because volcanic and anthropogenic aerosols have offset some warming that would otherwise have taken place. {2.9, 7.5, 9.4}
The observed widespread warming of the atmosphere and ocean, together with ice mass loss, support the conclusion that it is extremely unlikely that global climate change of the past fifty years can be explained without external forcing, and very likely that it is not due to known natural causes alone. {4.8, 5.2, 9.4, 9.5, 9.7}”
The daily Telegraph (and most other UK newspapers) has now finally reported the story of the blogger who found the error concerning 1998.
Gavin Schmidt, a climate modeller at GISS and author of the website RealClimate.org, is quoted in the article as playing down the significance of the error to AGW theory.
However the most interesting part to my mind is his having to revert to average temperature over the period 1998-2002 (rather than present) in order to try to impress upon that things are now much worse than the 1930's (when much less man-made CO2 was produced). That smacks of desperation to me, the scientific evidence for "AGW scaremongering" is crumbling to pieces!
"Dr Gavin Schmidt, a climate modeller at GISS and author of the website RealClimate.org, described the changes as "very minor re-arrangements".
He wrote in his blog: "The sum total of this change? A couple of hundredths of degrees in the US rankings and no change in anything that could be considered climatically important (specifically long term trends)."
He told Telegraph.co.uk that the corrections only affected US data.
"Global warming is fundamentally a global phenomenon - the average amount of warming across the world," he said.
"The principal issue with greenhouse gases is the global mean. And that is unaffected in any significant way by this correction.
"I would add that two indpendent analyses from the CRU and NCDC in Boulder, Colorado, are not affected by any issues at GISS and show the same rises in global temperature."
He cites the period between 2002 and 2006, where the average was 0.66ºC above the norm, as still being warmer than 1930-1934, where an increase of 0.63ºC was the largest in the early part of the century.
However both periods are below the 1998-2002 average temperature of 0.79ºC hotter than normal."
Originally posted by M Batchelor: However the most interesting part to my mind is his having to revert to average temperature over the period 1998-2002 (rather than present) in order to try to impress upon that things are now much worse than the 1930's (when much less man-made CO2 was produced). That smacks of desperation to me, the scientific evidence for "AGW scaremongering" is crumbling to pieces!."
You'll have to ask him yourself - maybe he was using an 8-9 long running mean i.e 1998 - 4 years- 2002 - 4 years - 2006
It's best to use an odd number of data points for a running mean as your values can be superimposed on the original values. An even number average falls between two values.
Anyrate the larger your time history the more obvious GW is which is better than a "yearly mean" (whatever that is!).
