By Steve Goddard
Earlier in the month I wrote an article showing the trend in Arctic ice since 2002.
I took a lot of criticism from people for not measuring “crest to crest or trough to trough.”
Any one schooled in analysis of cyclical data would know that one must go from crest-to-crest or trough-to-trough, to maintain some semblance of symmetry about the x-axis.
It is time now to see how serious people are about their belief systems. We have passed the 2010 El Niño peak, and can see what the “real” trend is since the cyclical El Niño peak of 1998.
http://www.woodfortrees.org/plot/rss/from:1998/last:2010/plot/rss/from:1998/last:2010/trend
“Global warming on decadal timescales is continuing without let-up … we conclude that there has been no reduction in the global warming trend of 0.15-0.2C/decade that began in the late 1970s.”
Talk about cherry-picking! Look at his start point. He chose the worst case trough to crest to measure his trend.
Question for readers. Is Hansen correct, or does he need some serious graphing lessons? Below are the trend graphs from 1998-present for all four sources. GISS is way out of line.
RW says:
July 31, 2010 at 8:45 am
“1. For a cyclical and regular time series, even measuring trends peak-to-peak or trough-to-trough is not meaningful. See here”
It certainly is. The trend is mathematically zero. I don’t know what the woodfortrees plotter thinks it’s doing, but what it isn’t doing is calculating a linear trend over the test dataset. I hope people haven’t been using it on real data, because it’s giving nonsensical answers. The programme seems to have a serious bug in it.
Alexej Buergin said (July 31, 2010 at 11:46 am):
Spencer’s MSU UAH shows 0.14C per decade over the full data set.
RSS is 0.16C per decade.
GISTEMP is 0.17C per decade.
HADCRUT3 is 0.16C per decade.
All from the excellent woodfortrees site.
I do think Spencer tries hard to minimise the warming in his data series.
What utter nonsense ! A hadcrut3 “trend” of 0.02 degrees in 10 years ? Where are the error bands ?
Surfacestations.org found errors of greater that 1 degree for over 90% of stations !! This is a factor of at least 50 greater, making any such trends meaningless. Even the recording accuracy is still listed as 1 degree. ( http://www.srh.noaa.gov/ohx/dad/coop/EQUIPMENT.pdf page 11 )
What difference does it make if the world is warming or cooling anyway ? The issue is whether man has had anything to do with it … something the IPCC and alarmists have no evidence whatsoever to support.
Icarus says:
July 31, 2010 at 8:09 am
Jean Meeus said (July 31, 2010 at 7:33 am):
May I be rude & ask what is the trend line since 1850??
Me thinks you will find it comes in very close to Zip, Zero.
regards
Jean Meeus, we have two generally accepted definitions of climate change circulating. They are not the same. I discuss this in my essay “Climate Change, Just What Is That Anyway?”. To sum: “…. From Wikipedia:
“For current global climate change, see Global warming.
For past climate change, see paleoclimatology and geologic temperature record.
Climate change is a change in the statistical distribution of weather over periods of time that range from decades to millions of years. It can be a change in the average weather or a change in the distribution of weather events around an average (for example, greater or fewer extreme weather events). Climate change may be limited to a specific region, or may occur across the whole Earth.” Now I can live with that as it meets all the needs of my science and I suspect others. I am sure it was written by someone knowledgeable in the scientific method and the Philosophy of Science. However, the Wikipedia authors go on to say:
“In recent usage, especially in the context of environmental policy, climate change usually refers to changes in modern climate. It may be qualified as anthropogenic climate change, more generally known as “global warming” or “anthropogenic global warming” (AGW).” I guess that explains my wondering. It is clear that two different definitions are in use. This is not good. It is very much not good, because it tends to cause confusion….”
Apologies. Just saw Pualhans reply and obviously sensible statement.
regards
@Paul Birch.
What are you saying? If sucessive peaks are identical but the shape of a curve deviates from being a pure sinusoid, so that the integral of the sucessive curves wrt time is increased, this has no meaning – “the trend is zero”?
This whole argument would benefit from a rather more rigorous definition of how temperature is defined as a function of time and the application of a mathematical model that recognises the complexities of the data. Fitting least squares line to a continuous signal that does not have a defined distribution is difficult to interpret and (@RW) since the distribution of the data is non-stationary, calculation of exact confidence limits is problematic.
paulhan said (July 31, 2010 at 1:35 pm):
What does that tell us? Not very much, considering that important forcings over that period, such as TSI and well-mixed greenhouse gases, are not changing linearly.
The great increase in atmospheric CO2 over that period is not a natural variation.
What indication is there of that?
What forcing, precisely, is responsible for us ‘coming out of a little ice age’? Please support this assertion with data.
The trouble is, there is around another 0.4 to 0.5C of warming in the pipeline due to the lag in ocean warming, just from ~390ppm of CO2, which takes us to 1.2C above pre-industrial. Then we have to consider how much higher atmospheric CO2 is going to rise – no-one seriously thinks that it’s going to stop rising anytime soon, so there will definitely be more warming on top of that 1.2C. Then also, we risk more warming still from any decline in anthropogenic aerosols (e.g. if industry in China cleans up its pollution). Considering the rapid decline of Arctic ice and glaciers and so on even at current warming, I don’t think our descendents are going to be laughing about our actions. Condemning us, perhaps.
Wow, I’m on a roll.
I must ask for opinions here. Mine is that the [snip] in the AGW cult have had a small victory of sorts by being able to draw everyone on the Skeptics side into short termism. ie. Last 10 years have been hottest since Marilyn Monroe…etc.
The claim by the cultists has to be seen in the context of the length of the Industrial Revolution. We should, I think walk away from the short termism and start hammering away at the reality of climate. It cycles. And since the 1840-50s the ‘warming’ has been statistically insignificant within those cycles. The claim of unprecedented warming and a tipping point are like ‘Jesus walked on water and heaven is full of virgins’ . The stuff of fanaticism & Emotional Terrorism.
The 1850 s are a nice central starting point as the American East was full of industry, Europe as well, so that awful CO2 was being produced in an ‘unprecedented’ amount.
waddayarekon??? Long term or short term ??
regards from a cold, wet Southern Oz.
RC Saumarez says:
July 31, 2010 at 2:40 pm
@Paul Birch.
“What are you saying? If sucessive peaks are identical but the shape of a curve deviates from being a pure sinusoid, so that the integral of the sucessive curves wrt time is increased, this has no meaning – “the trend is zero”? ”
RW said:“1. For a cyclical and regular time series, even measuring trends peak-to-peak or trough-to-trough is not meaningful. See here”
For any “cyclical and regular time series”, such as the pure sine curve used in the test case RW linked, the trend over any integer number of periods is mathematically zero. The script gets that wrong, even for very simple cases, so there’s a bug in it.
I think I see part of the problem. It looks as if when the trend is zero it fails to draw the red line at all. You have to add a little bit to the end time. Btw, by “cyclical and regular” I understand symmetrical about the peaks or troughs. The trend is not necessarily zero for an asymmetrical periodic function, nor between points other than extrema on a symmetric function.
I tried to recreate your graph on the top on the page. Initially I thought there was someting wrong with R. No matter how I tried R kept turning up a horizontal line. After 1,5 hours I gave up and imported the data to Excel and surprisingly I got the same result. The “trend” was absolutely horizontal!
Only then did I realise that my data was more up to date hence a little longer and since the curve is going downwards those last numbers resulted in a flat trend. It only goes to show how trends can be affected by short series and selection of start and stop values for the trendline. Soon it will go slightly downwards and then we will see the newspaper articles again and in the winter it will go up again.
I guess we can safely say: there’s not much going on here!
Icarus says:
July 31, 2010 at 2:18 pm
…….”I do think Spencer tries hard to minimise the warming in his data series.”
==
Any other opinions, you care to share with us?
nevket240, it’s the contrarians who are always claiming “It’s been cooling for the last 3 years! Global warming is dead!”. Short-termism is their province.
Icarus,
Amazingly bad luck for the human race that the satellites came on line in 1979.
http://climateinsiders.files.wordpress.com/2010/07/fig-a2-lrg2.gif
This has given Hansen cover for his cherry-picked trend.
GISTemp is so obviously tampered with it’s easy to find these things.
stevengoddard says:
July 31, 2010 at 5:14 pm
Amazingly bad luck for the human race that the satellites came on line in 1979…
This has given Hansen cover for his cherry-picked trend.
______________________________________________________-
You have that correct Steve. If the satellites had come on line in 1929 we would have seen the sine wave pattern due to the ocean oscillations instead of a linear approximation of one side of the curve.
Here is what I mean typical graph of an east coast city
Icarus says:
July 31, 2010 at 4:29 pm
Only in response to the Goebellists constant media howls of the the ‘hottest 10 years in the last 5’ dah dah adh. 🙂
1908-1942 (+/_) mmmmmm
1942-1976 (+/-) mmmmmmmm
1976-2005 (+/-) mmmmmmmmmmm
bloody cycles. I wish they wouldn’t keep going around, and around…
regards
Icarus says:
July 31, 2010 at 2:45 pm
paulhan said (July 31, 2010 at 1:35 pm):
When I look at the long term HADCRUT and superimpose a linear trend on that, it shows a 0.7 rise over the 160 years.
What does that tell us? Not very much, considering that important forcings over that period, such as TSI and well-mixed greenhouse gases, are not changing linearly.
However that is with 3 peaks and 2 troughs of a lumpy sine wave, which correlates very closely with the PDO cycles, and could be said to be entirely attributable to natural variation.
The great increase in atmospheric CO2 over that period is not a natural variation.
There is every indication that we are past the beginning of a cool cycle…
What indication is there of that?
Given we were coming out of a little ice age, I don’t think there’s anything here to be getting alarmed about.
What forcing, precisely, is responsible for us ‘coming out of a little ice age’? Please support this assertion with data.
Further, it is only this 0.6C rise that we can attribute anything not natural to, such as greenhouse gasses or other forcings, and that is assuming that this 180yr trend isn’t just part of a longer cycle, possibly headed down again given our weak sun.
Dr Lindzen was right. Our descendants are going to have a good old laugh at our version of arguing over angels on pins.
The trouble is, there is around another 0.4 to 0.5C of warming in the pipeline due to the lag in ocean warming, just from ~390ppm of CO2, which takes us to 1.2C above pre-industrial. Then we have to consider how much higher atmospheric CO2 is going to rise – no-one seriously thinks that it’s going to stop rising anytime soon, so there will definitely be more warming on top of that 1.2C. Then also, we risk more warming still from any decline in anthropogenic aerosols (e.g. if industry in China cleans up its pollution). Considering the rapid decline of Arctic ice and glaciers and so on even at current warming, I don’t think our descendents are going to be laughing about our actions. Condemning us, perhaps.
Global warming rate in the 30-years period from 1970 to 2000, after 60 years of human emission of CO2, was nearly identical to that for the 30-years period from 1910 to 1940 as shown in the following graph for the CRU data:
http://www.woodfortrees.org/plot/hadcrut3vgl/from:1910/to:1940/compress:12/plot/hadcrut3vgl/from:1910/to:1940/trend/plot/hadcrut3vgl/from:1970/to:2000/compress:12/plot/hadcrut3vgl/from:1970/to:2000/trend
Global warming rate from 1910 to 1940 => 0.15 deg C per decade
Global warming rate from 1970 to 2000 => 0.16 deg C per decade
And what is the current global warming rate?
A slight warming of 0.03 deg C per decade as shown here:
http://www.woodfortrees.org/plot/hadcrut3vgl/from:1990/to:2000/plot/hadcrut3vgl/from:1990/to:2000/trend/plot/hadcrut3vgl/from:2000/to:2010/plot/hadcrut3vgl/from:2000/to:2010/trend
Note the deceleration of the global warming rate compared to that for the period from 1990 to 2000. Actually, the deceleration is by a factor of 8.3 (=0.25/0.03)
CONCLUSIONS
The effect of human emission of CO2 on global mean temperature is NIL, ZIP.
The recent global warming rate is NOT unprecedented.
Icarus says:
…The great increase in atmospheric CO2 over that period is not a natural variation…
…What forcing, precisely, is responsible for us ‘coming out of a little ice age’? Please support this assertion with data…
What amount of the current warming trend comes from natural variation, and what are the components of that variation? What amount of the current warming trend comes from CO2?
RE: Dave F: (July 31, 2010 at 7:58 pm) “What amount of the current warming trend comes from natural variation, and what are the components of that variation? What amount of the current warming trend comes from CO2?”
I believe the basic problem here is the fact that our climate appears to be controlled by a poorly understood random convective thermal control system. Perhaps blaming the CO2 greenhouse effect for our modern temperature increase in like blaming the heat from your TV set for making your house warmer while the kids are playing with the thermostat.
Icarus says:
…Then also, we risk more warming still from any decline in anthropogenic aerosols (e.g. if industry in China cleans up its pollution). Considering the rapid decline of Arctic ice and glaciers and so on even at current warming, I don’t think our descendents are going to be laughing about our actions. Condemning us, perhaps…
Chinese kids with cleaner air? Not exactly comical, but hardly condemnable.
I says:
“Chinese kids with cleaner air? Not exactly comical, but hardly condemnable.”
I meant – ‘breathing’ cleaner air.
Icarus says:
July 31, 2010 at 2:45 pm
……
The trouble is, there is around another 0.4 to 0.5C of warming in the pipeline due to the lag in ocean warming, just from ~390ppm of CO2, which takes us to 1.2C above pre-industrial.
But is there more in the pipeline? It’s looking increasingly likely that most of the heating from CO2 forcing to date has been realised. This is this “missing heat” that Trenberth was looking for. It’s simply not there.