* Posts by John Philip

21 publicly visible posts • joined 5 May 2008

Scorchio! This June was the sixty-sixth hottest on record

John Philip

Nice cherry-pick, Lewis. Up to the usual standard. Here are a couple more from the linked UK ranked months chart: 6 out of the hottest 12 Junes on record occurred since 2000, and here are the 8 hottest calendar years:

2014, 2006, 2011, 2007, 2003, 2004, 2002, 2005

Notice anything?

Adjustments to raw data occur in every field, for perfectly good reasons. As Zeke Hausfather of the Berkely Earth project has shown, the adjusted global numbers actually trend *lower* than the raw data.

http://judithcurry.com/2014/07/07/understanding-adjustments-to-temperature-data/

New science: seas will rise due to CO2 ... but not for centuries

John Philip
Thumb Down

Usual fact-free rubbish

Oh, Lewis, Lewis. You really should learn to read the paper before you give us your rose-tinted 'analysis'. You say 'our children and our children's children will not have to face so much as a metre of sea level rise' and seem to advocate no action at all on reducing greenhouse emissions.

But this sunny scenario is based on emissions CEASING by 2100 ...

"These assume a 21st century increase in greenhouse gases according to SRES scenarios B1, A1B and A2 with a stabilization of the atmospheric composition after the year 2100". To stabilise the atmosphere, we would have to reduce our emissions to zero over the next eighty-seven years. Hard to see how that could be achieved unless we start at least planning it now.

So a BAU policy, far from leading to the scenarios that are the basis of this article, leads us inevitably to a higher sea level rise than that discussed. You're misleading us Lewis, either intentionally or by shoddy research.

By 'research' I mean ACTUALLY READING THE PAPER.

What's the cost of global warming?

John Philip

Weapons grade balonium

That should be erratum. Which says it all really.

YIKES, however, is apposite.

John Philip
Stop

Did you actually READ the Stern review?

A tip - when in a hole, stop digging.

"the assumption of a 1.3% growth in consumption between now and 2200 is absurdly low. Not only that, but that figure assumes no impact whatever from climate."

The figure is not actually Stern's. He derives it from the PAGE2002 model. I'll leave you to Google the acronym, but I'll start you off with a clue... the G stands for Greenhouse.

Sugning off now, I really do have better things to do with my time.

John Philip

Very amusing

"That is a distinction with almost no difference. Change wording to consumption, then."

LOL! I am sorry but you simply cannot, in a piece purporting to be a serious economic analysis, say that the difference between consumption and production is negligible and expect to be taken seriously. That, and the many other factual errors render the analysis incredible.

Regards to Steve Goddard.

JP.

John Philip
Thumb Up

Reprise

Oh, I posted a few suggestions on improvements to the original piece, I am not going to type them all out again, here are just the worst factual errors and chery-picks

Factual error: Stern did NOT use the IPCC worst case, he reported on the effects of a range of possible temperature increases, however for his economic modelling he favours IPCC scenarios A2 and A1F1, which are actually mid range scenarios.

Factual error: The 550ppm figure quoted by Stern is CO2 equivalent (CO2e). This is a measure of the effect of all GHGs, with the effects of the non-CO2 gases converted to the equivalent conentration of CO2. Your 385ppm figure is for CO2 only. The current CO2e figure is actually about 430ppm.

Factual Error; Hurricane intensity has increased since the seventies - the number of Cat 4 and Cat 5 storms has nearly doubled. http://www.sciencemag.org/cgi/content/abstract/309/5742/1844

Factual Error: 1.3% is Stern's figure for the growth in CONSUMPTION, not GDP. (Chapter 6 Page 161)

Misleading and Selective: "Direct benefits from $800bn spent on direct mitigation of global warming would yield only 90 cents' benefit per dollar."

The report in question considered 4 scenarios, you have quoted only the worst case, mitigation only, that has a negative outcome. Yohe found that a more realistic mix of mitigation. R&D and adaptation yields a return of $2128bn for the $800bn outlay.

See table 4.1 here http://www.copenhagenconsensus.com/Admin/Public/Download.aspx?file=/Files/Filer/CC08/Papers/0%20Challenge%20Papers/CP_Global_Warming_-_Yohe.pdf

Factual Error: Stern projects that extreme weather alone will result in an increased loss of several percent of GDP

Where does he? In the exec summary Stern projects a loss by 2050 of 0.5 to 1% GDP. The current figure is approx 0.2% so his proejcted increase is at most 0.8%. He states this will increase further but nowhere gives the figure attributed to him.

And so on and so forth, Lomborg's claim on increased heat deaths vs reduced cold deaths is anatomised here:

http://www.lomborg-errors.dk/coolitBchap2heat.htm

in a website set up solely to catalogue his many scientific errors.

Hope this helps. and bye for now.

John Philip
Stop

Censorship

"The model I prefer is the observed record. And, for that matter, those observations appear to have been exaggerated by surface station site violations by, perhaps, a factor of two."

What does that mean exactly? ANd if the surface station record is exaggerated, why does it correspond so closely with the satellites ... http://tamino.files.wordpress.com/2008/03/4way.jpg ?

"First, they grossly overestimated sea level rise (both ice melt and thermal expansion). Not because of their model or their input, but because they had done their sums wrong. This was pointed out, and they made the correction via supplement, but it's still in the AR4 body that makes all the rounds."

If you mean the typo spotted by Viscount Monckton then you are misttaken, it has been corrected in the main text. The sea level rise projections in the 2001 AR3 turned out to be a slight underestimate by contrast

http://www.sciencemag.org/cgi/content/abstract/1136843

"Second, they still cling to the hockey stick".

Hardly. In addition to Mann, we have many other reconstructions, eg Moberg (2005), all of which reinforce the basic conclusions. See the NAS report ...

"The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes both additional large-scale surface temperature reconstructions and pronounced changes in a variety of local proxy indicators, such as melting on icecaps and the retreat of glaciers around the world, which in many cases appear to be unprecedented during at least the last 2,000 years."

http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=6222006

Mann updated the Hockey Stick study just this year and released every last scrap of data and code that supports it. Oh, and even his critics concede that changing the PCA centring has negligible impact on the conclusions.

"Third, the Aqua Satellite indicates (so far) that they are grossly overestimating the positive feedback number, and in fact the feedbacks are negative."

Nope. http://www.terradaily.com/reports/Increase_In_Atmospheric_Moisture_Tied_To_Human_Activities_999.html

You shouldn't believe everything you read in The Australian.

Anyhoo, that's three factual errors. I am lowering my usual 'I give up' threshold because you did not see fit to release my earlier little critique and its references and animadversions. Ironic, then, that you complain of scientists limiting access to information huh?

;-)

Are the ice caps melting?

John Philip

More Ice Facts

"There weren't any accurate records of Antarctic sea ice prior to satellites. We are on track to break the record again for most sea ice this year."

Hmmm, you'd better inform the Hadley Centre - their dataset has observations dating back to the last century. I refer you to this paper :

http://hadobs.metoffice.com/hadisst/HadISST_paper.pdf

and this NASA article

" ... there was a dramatic loss of Antarctic sea ice cover from 1973 to 1977, and since then the ice has gradually spread in area. The increase has been slow enough that it does not totally wipe out the earlier decreases, said Claire Parkinson, senior researcher at NASA's Goddard Space Flight Center, and a co-author of the paper.

Overall, from 1972 to 2002, the Antarctic ice declined on average by 150,000 square kilometers per decade. "

http://earthobservatory.nasa.gov/Newsroom/NasaNews/2003/2003111016173.html

Or this more recent piece ...

Isabella Velicogna and John Wahr, both from the University of Colorado, Boulder, conducted the study. They demonstrated for the first time that Antarctica's ice sheet lost a significant amount of mass since the launch of GRACE in 2002. The estimated mass loss was enough to raise global sea level about 1.2 millimeters (0.05 inches) during the survey period; about 13 percent of the overall observed sea level rise for the same period. The researchers found Antarctica's ice sheet decreased by 152 (plus or minus 80) cubic kilometers of ice annually between April 2002 and August 2005.

http://www.nasa.gov/home/hqnews/2006/mar/HQ_06085_arctic_ice.html

'Breaking the record' is only newsworthy if the rate of increase is statistically significant. This is true of the Arctic ice extent, currently decreasing at -200 000 km2 or 3% per decade (faster in recent years) but not of Antacrtic ice extent for which the recent rate is +100,000 km2 or just 0.8% per decade.

"Northern hemisphere sea ice area is nearly 1,000,000 km2 greater than last year."

Yes, but remember also that 2007 was a record-shattering year for Artic ice extent, some 23% below the previous record ....

"Arctic sea ice extent for June 2008 is close to that for 2007, which went on to reach the lowest minimum since at least 1979. More notably, however, satellite data indicate that melt began significantly earlier than last year over most of the Arctic Ocean. The large area of the Arctic Ocean covered by first-year ice (described in our June analysis), coupled with the early onset of melting, may mean more rapid and more severe summer ice retreat than last year. "

http://nsidc.org/arcticseaicenews/

cheers,

JP.

John Philip
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Blatent Misrepresentation

"As shown in Figure 2-2 from the article, Hansen calculated that both the Arctic and Antarctic would warm by 5-6 degrees Centigrade. His predictions were largely incorrect, as most of Antarctica has cooled and sea ice has rapidly expanded. The evidence does not support the theory."

Except the whole paper is an examination of what is projected to happen after CO2 levels rise by a factor of two. We're several decades away from that, so how can you possibly claim that Hansen's predictions were wrong?

In fact the delayed response of the Antarctic is predicted by the models, and averaged overall the continent,inclduing the rapdily warming Antarctic Peninsula the last 40 years show a slight warming. (Bertler et al. 2004)

"while the Antarctic broke the record for the most sea ice area ever recorded. "

Nope - the highest since satellite measurements began perhaps but just lookkee at what happened prior to that ...http://tamino.files.wordpress.com/2007/10/shwwzmu.JPG

Bit of an accuracy-free zone, this one.

JP.

Painting by numbers: NASA's peculiar thermometer

John Philip
Happy

Good luck with that!

Thanks for the links. As Joseph Romm points out, Keenlyside et al actually predicted

• The “coming decade” (2010 to 2020) is poised to be the warmest on record, globally.

• The coming decade is poised to see faster temperature rise than any decade since the authors’ calculations began in 1960.

• The fast warming would likely begin early in the next decade — similar to the 2007 prediction by the Hadley Center in Science (see “Climate Forecast: Hot — and then Very Hot“).

• The mean North American temperature for the decade from 2005 to 2015 is projected to be slightly warmer than the actual average temperature of the decade from 1993 to 2003.

http://climateprogress.org/2008/05/02/nature-article-on-cooling-confuses-revkin-media-deniers-next-decade-may-see-rapid-warming/

“You said that the poles should warm faster than the tropics - yet the tropics are barely warming, Most of Antarctica is cooling and has record sea ice, and the Arctic is warming.

Sounds like a good topic for an story! Thanks.”

Actually it is just the Arctic that is predicted to warm (first), as the Antarctic is surrounded by an enormous heat sink in the form of the Southern Ocean.

Anyway, good luck with that, you might be interested in the comparison of Artic and Antarctic ice here http://nsidc.org/seaice/characteristics/difference.html

Bye for now.

JP

PS If you ever want to determine the difference in the height of two people, make sure one of them is not standing on a box ;-)

John Philip

Hi Steve

"The divergence graph shows a steady increase 1998, whatever the baselines may be. The point is that the delta should be fixed, regardless of the baselines."

Not necessarily. The long term warming trend is best characterised as a linear warming signal plus 'noise'. The noise being relatively short-lived (a few years) evnts such as the ENSO events El Nino, which raises temperatures and La Nina which cools. The satellites measure the temperature in the troposphere which seems to be pushed higher than the surface record by the El Nino and vice versa for La Nina. If your start point is in an El Nino year (1998 was the strongest El Nino of the last century) and your end point in a La Nina then some divergence between surface and satellite trends is not unexpected.

"The US has the vast majority of, and the best USHCN stations. There is no reason to believe that US temperatures behave in a tremendously different fashion from the rest of the world. According to NASA, the US has warmed in lockstep with the rest of the world."

Huh? its a landmass. Most of the globe is ocean (proportion rising ;-)) which warms in a very different fashion, in fact seems to have cooled slightly over the last 4-5 years. Then there is the prediction of the theory that the Arctic will warm faster than the tropics, so called polar amplification:

"The map reveals that the greatest warming has been in the Arctic and neighboring high latitude regions. Polar amplification is an expected characteristic of global warming, as the loss of ice and snow engenders a positive feedback via increased absorption of sunlight. The large Arctic warm anomaly of 2007 is consistent with observed record low Arctic sea ice cover in September 2007."

That's from NASA's summation of 2007. http://data.giss.nasa.gov/gistemp/2007/

The US is representative of the US, nothing else.

"I don't disagree with your point that climate alarmism is largely a media invention, regardless of which direction it is headed."

That wasn't my point. Alarmism is perjorative; current genuine concerns are backed by an unprecedented and overwhelming majority within the discipline of climate science, the National Academies of Science, and endorsed by every relevant professional association of scientists...

http://www.sciencemag.org/cgi/content/full/306/5702/1686

http://royalsociety.org/displaypagedoc.asp?id=20742

http://www.agu.org/sci_soc/policy/positions/climate_change2008.shtml

(etc etc)

JP.

PS A reminder, I asked where were the '20 year cooling' studies' you mentioned were published please?

John Philip

But it does

"It should, but it does not, because there are more temperature stations in the US than any other country (by a considerable number)."

Correct premise. False conclusion. The mean is calculated from a series of grid boxes. Each box in a particular latitude band is weighted equally. So the contribtion of any particular area is proprtional to the size of the area, not the number of stations. The number of stations will increase the accuracy of the reading, but not its weighting.

See the documentation on the NASA website.

John Philip
Alien

Critique

Hi Steve,

Could you help me with the following?

1. "At the same time, there are new scientific studies showing that the earth is in a 20 year long cooling period. "

Could you tell me in which academic journals I can find these studies?

2. These quotes

"In 1998 (left side of the graph below) NASA and the satellite data sources RSS and UAH all agreed quite closely "

"The NASA temperature map for March above shows Alaska temperatures much above "normal", while the UAH map shows Alaska temperatures well below "normal"."

"Nevertheless, the difference between March UAH and GISS global is still 0.5 degrees."

strongly indicate that you were not aware that the NASA and satellite data series have different baselines when you wrote the piece. Is this the case? If not, can you explain how you came to these conclusions?

3. "Using set theory, it is impossible for a subset of size 30 to be near the median and the full set to be in the top three. Absolute worst case would be in the top 15 for the full set."

I think you are confusing your sets. We have (a) the set of NASA global temperatures, we have (b) the set of UAH Southern Hemisphere temperatures, Your observation was that March 08 is near the top of (a) but near the bottom of (b). So what? I propose a more relevant set (c) the set of UAH global temperatures. March 08 is 4th highest in (a) and 13th in (c).

A bit less newsworthy but statistically waaay more legitimate.

4. "Viewing the NASA 250-mile map for March below,"

Its actually the 250Km map isn't it? And NASA prefer a 1200km radius, this being closer to the distance over which temperatures actually correlate.

5 "A second important issue with NASA's presentation is that they use the time period of 1951-1980 as their choice of baseline. This was a well known cold spell, as can be seen in the 1999 version of the NASA US temperature graph below."

It may have been a well-known cold spell in the US, however the NASA baseline is global. Why do you show a US map to make a global point? continental US is maybe 2% of the global surface area. Please explain.

6. "Temperatures dropped enough during that period to trigger concern about the onset of an ice age. Newsweek magazine went so far as to mention a proposed "solution" of spreading soot in the Arctic to melt the polar ice caps. "

1970s Global Cooliing' was largely a media invention. Outside of Newsweek, can you steer me towards the explosion of concern about global cooling in the academic literature of the 1970's that corresponds to the contemporary >1000 papers on AGW? I am thinking of in particular this paper from the American Meteorological Society:

THE MYTH OF THE 1970S GLOBAL COOLING SCIENTIFIC CONSENSUS http://ams.confex.com/ams/pdfpapers/131047.pdf

which found "During the period 1965 through 1979, our literature survey found 7 cooling papers, 19 neutral and 42 warming. In no year were there more global cooling papers than global warming. "

Clutching at straws, me.

JP.

John Philip
Stop

Another straw

Thirty years is the size of the UAH dataset, but it is a monthly dataset, hence the meaning of the subset sentence still remains opaque to bears of little brain like me.

If we assume that Paul Clark has his baseline sums right, then the absolute difference between NASA and UAH in March was around 0.26C

Contrary to assertions, NASA know all about error bars - they are the little green lines here, for example : http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif

and the uncertainty in GISTEMP is normally put at c0.1C.

So, if we assume a similar uncertainty in the satellite record (historically plagued with errors), the difference between the tropospheric temperature and surface in March could feasibly be less than 0.1C.

Hold the front page!

John Philip
Boffin

Don't try and blind me with science

Steve,

Re: Using set theory, it is impossible for a subset of size 30 to be near the median and the full set to be in the top three. Absolute worst case would be in the top 15 for the full set.

I have no doubt this is a profound and absolutely true statement, but its relevence to your article or the responses to it escapes me. What exactly does the 'subset of size 30' refer to?

In plain English, serious questions remain. Lets try one last time ...

The article does this comparison regarding March 08 :

NASA (Global) : 4th warmest

UAH (Southern Hemisphere Only) : 2nd coolest on record.

but as the SH is mainly ocean, it is warming at a lower rate than the NH. So comparing Apples with Apples:-

NASA (global) : 4th warmest.

UAH (global) : 13th warmest. (I make that approx 340th coolest).

Do you think you could explain, without reference to set theory, why, in an article that makes accusations of cherry picking, you selected the Southern Hemisphere only instead of the globe to compare with NASA?

thanks,

JP

PS Here is the global UAH data for March in order of warmth:

1 1998 0.53

2 2004 0.45

3 2007 0.4

4 2002 0.38

5 2005 0.35

6 2006 0.33

7 1991 0.29

8 1983 0.25

9 1988 0.22

9 2003 0.22

10 2001 0.16

11 1981 0.13

12 1990 0.1

13 2008 0.09

John Philip
Alert

Confused?

"1200 miles is the distance between London and Catania, Sicily. Does it make sense to use data from Sicily when calculating the map color in London? Does the temperature in London or Catania tell you anything about the temperature in Lisbon? "

Er, its 1200km, Steve. More like London-Vienna.

John Philip
Boffin

Compare Apples with Appels and steer clear of the Cherries.

Steve

I appreciate you taking the time to respond ... however your statement that:

"Nevertheless, the difference between March UAH and GISS global is still 0.5 degrees."

is not correct. The arithmetical difference between the two is 0.51C BUT THEY HAVE DIFFERENT BASELINES. The average from which the satellite anomaly is calculated is (from memory, I am on a restricted PC right now) HIGHER than the NASA baseline by > 0.1C. You have to take this into account when doing comparisons, I really would have expected someone writing on this topic to appreciate this. Anthony Watts made a similar blunder on his site and you can find a review of the right way to do it on Tamino's Open Mind blog.

http://tamino.wordpress.com/2008/03/02/whats-up-with-that/

That still leaves a discrepency, but given measurement uncertainties, methological differences and the fact that the satelites measure a different physical quantity to the surface stations, not worthy of a conspiracy theory.

After all, go back to April 1998, the El Nino and the equivalent numbers are:

UAH : 0.76C

NASA : 0.27C

Clearly, UAH has a serious warm bias.... ;-)

Meanwhile we still have the claim ...

" Looking closer at March 2008, NASA's data shows the month as the third warmest on record. In sharp contrast, UAH and RSS satellite data showed March as the second coldest on record in the southern hemisphere, and just barely above average for the whole planet. How could such a large discrepancy occur?"

Well it occurs because you are comparing a global figure with a hemisphere figure. (Perhaps you could explain why, when the UAH global data is freely available?) Rankings do not convey much information, however The NCDC analysis of the March 08 UAH data said that, globally, March was the thirteenth warmest:

http://www.ncdc.noaa.gov/oa/climate/research/2008/mar/global.html

Not such a startling revelation.

yours, attempting to keep an open mind

JP.

John Philip
Alert

Just one more point

" Looking closer at March 2008, NASA's data shows the month as the third warmest on record. In sharp contrast, UAH and RSS satellite data showed March as the second coldest on record in the southern hemisphere, .... "

Hemispheres notwithstanding, iIt just occurred to me that the UAH record only goes back to 1979, as opposed to 1880 for NASA, so 'nth coldest on record' really is not all that impressive.

Trying REALLY HARD to maintain an open mind.

JP.

John Philip

Steve re: NASA data locations

Er-hem ...Smoothing radius: Distance over which a station influences regional temperature, either 250 km or 1200 km (standard case = 1200 km).

Amazingly the map looks a lot less sparse when you select NASA's standard case.

"Looking closer at March 2008, NASA's data shows the month as the third warmest on record. In sharp contrast, UAH and RSS satellite data showed March as the second coldest on record in the southern hemisphere, and just barely above average for the whole planet. "

Has some text been added there? What on Earth is meant by 'the average'? Average since when? If it is the baseline for the data series then this is not so impressive, the satellites anomaly is measured compared with the average temperature from 1979-2000. A period that includes the record breaking 1998: http://wattsupwiththat.files.wordpress.com/2008/05/rss-msu-monthly-anom_042008.png

That March 08 is only slightly warmer than the average for the last fifth of the preceding century seems to me less than pursuasive.

Also the data does not support the claim that NASA has March 08 as third warmest, just looking at 2001 onwards there are 16 warmer months

2001 38 41 54 39 51 47 50 45 48 44 67 51

2002 71 70 84 58 56 46 56 45 48 49 51 36

2003 65 51 51 49 51 39 49 63 60 66 49 68

2004 52 67 58 52 37 33 22 43 46 58 63 51

2005 69 56 70 64 55 59 55 56 68 71 64 59

2006 43 58 55 46 42 53 43 58 55 60 62 69

2007 86 63 60 64 56 53 53 57 51 55 49 40

2008 13 26 60 41

See http://data.giss.nasa.gov/gistemp/graphs/Fig.C.lrg.gif. Even by a simple eyeballing you can see March 08 as third warmest cannot be correct.

A single month is not indicative of very much, and remember that the satellites and the surface records are measuring different quantities so, while we would expect a broad correlation

(which is what we do see ... http://tamino.files.wordpress.com/2008/03/4way.jpg ) , a single month when there is some divergence proves nothing.

I notice that one of the para headings is 'Cherry Picking'. Comparing the global figure from the NASA dataset with the Southern Hemisphere from another to show NASA is too warm would be legitimate if both hemispheres showed good agreement: http://data.giss.nasa.gov/gistemp/graphs/Fig.A3.lrg.gif

Oh dear.

JP.

John Philip
Thumb Down

Every bit as good as the last one

1. Why focus so much on the US? It only contributes approx 2% to the global mean. The problem is global warming.

2. "what immediately grabs the attention is that NASA has essentially no data (gray areas) in most of Canada, most of Africa, the

Greenland ice sheet, and most of Antarctica "

Really? What are all these little red dots? http://www.giss.nasa.gov/research/features/temptracker/global_weather_stations_map_532.gif

3. "In 1998 (left side of the graph below) NASA and the satellite data sources RSS and UAH all agreed quite closely - within one-tenthof a degree."

They do not 'agree quite closely' as the satellite and NASA datasets have different baselines (zeroes). It is not legitimate to plot them with the same y-axis without adjustment for this. The NASA anomaly baseline was chosen as a period of good quality coverage, it

does not imply any kind of 'normal' temperatures (and Why show a US map to illustrate a point about the global record? Hmmm). The difference in trends post-1998 is probably explained by the fact that the satellite and urface stations measure different quantities, the surface and lower tropospheric temperature respectively. 1998 was a strong El-Nino year which pushed temperatures two standard deviations above the trend line. I speculate that this effect was more prominent in the satellite record hence the differing trends since then. To see the long term comparison try http://www.columbia.edu/~jeh1/mailings/20080303_ColdWeather.pdf

4 NASA's data shows the month as the third warmest on record. In sharp contrast, UAH and RSS satellite data showed March as the second coldest on record in the southern hemisphere

Ho Ho. Not so much Apples and Oranges as Apple with half an Apple. The US NCDC found March the second warmest on record: http://www.ncdc.noaa.gov/oa/climate/research/2008/mar/mar08.html

Can we expect a Register article on this sinister organisation soon ;-)

JP.

Is the earth getting warmer, or cooler?

John Philip
Alert

Just a few points ...

Steve,

While you're chasing Hansen's 'adjustment' down could you answer this for me?

You wrote "The UK Meteorological Office’s Hadley Center for Climate Studies Had-Crut data shows worldwide temperatures declining since 1998. According to Hadley’s data, the earth is not much warmer now than it was than it was in 1878 or 1941. By contrast, NASA data shows worldwide temperatures increasing at a record pace - and nearly a full degree warmer than 1880."

1. Why did you choose different dates for the two data series? The NASA data starts in 1880 but you chose to go back to 1878 for Hadley, is it because 1878 happened to be >0.2C warmer?

2. Historically you use whole year means. Fair enough, except for Hadley 'present day' you seem to be using the 2008 YEAR TO DATE anomaly of 0.232, which is distorted by the unusually cool (La Nina) Feb 08. Is this legitimate?

3. Why did you use NASA's own plot, but 'roll your own' for Hadley (on a different scale). There's a perfectly good Hadley graph here: http://www.cru.uea.ac.uk/cru/info/warming/gtc2007.gif

4. If the NASA figures show 'record pace warming' since 1998, why does their website say ..."2007 tied 1998, which had leapt a remarkable 0.2°C above the prior record with the help of the "El Niño of the century"? http://data.giss.nasa.gov/gistemp/2007/

5. Here are the numbers from the relevant years ...

Hadley : NASA

1878 -0.018

1880 -0.249 : -0.25

1941 0.062 : 0.11

1998 0.526 : 0.57

2007 0.396 : 0.57

2008 0.232 :

Point-to-point comparisons really are not that legitimate, but using the Hadley full year figure for 2007 as 'present day' it is clear that

- NASA does not show temperatures 'increasing at record pace since 1998', the delta is zero.

- NASA 1880 to 2007 +0.82C, Hadley +0.64

- NASA 1941 to 2007 +0.46C. Hadley +0.33

Do you really see anything too troublesome there?

6. Would it not be closer to the truth to say that since the (anomalously warm) 1998, a linear fit for both datasets show a modest warming, with the small difference entirely explicable by the difference in methodology? Something like this http://tamino.files.wordpress.com/2007/08/t1998.jpg ?

Minor points: global mean temperatures are quoted with an uncertainty of around 0.1C, not 0.01C, The IPCC does not issue projections on a scale as short as a single decade (nor should they). US temperatures are a tiny fraction of the global mean.

cheers

JP

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