Climatologists now require 20 to 30 years to even consider any climatic trend: Is that really honest, or is it just very convenient?
Guest essay by Stephane Rogeau of France
So that’s it: the 15+ years period of no temperature increase is, according to the IPCC, a non-event, barely worth mentioning in the Summary for Policy Makers (SPM). The explanation is simple: we are just witnessing short usual natural variations of the climate that are consistent with climate models. The question about whether those models had foreseen this so-called “hiatus” is just irrelevant: move along!
But let’s just imagine for a while that since around 2000, the world had seen a warming bigger than everything the IPCC had ever predicted. I mean a situation just opposite to what we have been experiencing until now with regard to model forecasts. What would have been the analysis proposed by the IPCC in its SPM report?
First possible analysis:
“The long-term climate model simulations show a trend in global-mean surface temperature from 1951 to 2012 that agrees with the observed trend (very high confidence). There are, however, differences between simulated and observed trends over periods as short as 10 to 15 years (e.g., 2000 to 2012). Due to natural variability, trends based on short records are very sensitive to the beginning and end dates and do not in general reflect long-term climate trends. As one example, the rate of warming over the past 12 years (2000–2012; 0.23 [+0.13 to +0.33] °C per decade), which begins after the effect of a strong El Niño disappeared, is bigger than the rate calculated since 1951 (1951–2012; 0.12 [0.08 to 0.14] °C per decade).
The observed extra increase in surface warming trend over the period 2000–2012, as compared to the period 1951–2012, is due in roughly equal measure to an increased trend in radiative forcing and a warming contribution from internal variability, which includes a possible redistribution of heat within the ocean.”
Second possible analysis:
“The rapid increase in surface warming during the last period of more than 12 years is a clear sign that, although climate models have gained in precision in their description of climate behavior, several factors had been under-estimated by the scientific community in the AR4. There is strong evidence that both lower and upper limits of the former estimation of transient climate response should be risen by as much as 1°C (very high confidence).
Projections for annual mean surface temperatures for the period 2081-2100 have therefore been reviewed to take into consideration the change in observed trend over the last period of 12 years. All different scenarios now show a very likely increase of global mean surface temperatures of more than 1.5°C by the end of the century, relative to 1985-2005, and up to 6°C in the RCP8.5 scenario.”
Let’s be honest: does anybody believe the IPCC would have chosen to write anything close to the first analysis?
Related: To the IPCC: Forget about “30 years”
Tom J says: @ur momisugly October 2, 2013 at 7:01 am
….I just read this morning that only 6.6% of the EPA employees have been deemed essential and will be retained during the shutdown. The remainder will be furloughed. What a glorious way to begin the day. Just think of how much better off we’d all be if the same could occur at the UN. After all, the US does pay for 40% of the UN’s budget…..
>>>>>>>>>>>>>>>>>>>>>>>
Sounds like a darn good reason to continue the shut down until the end of 2016. Then maybe the states would grow a backbone and realize they don’t really need the federal government bribes.
What would the IPCC have written if there had been 12 years of rapid warming?
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What would the IPCC have written if we had this technology 1000 years ago?
We would have been at the peak of the MWP and falling into the LIA….
…it would have been hysterical!
Kev-in-Uk says:
October 2, 2013 at 6:16 am
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CET getting colder since 2000. Winter temps down by 1 degree centigrade.
http://www.metoffice.gov.uk/hadobs/hadcet/
[Remember, many new readers – and some older ones as well – don’t know all of the abbreviations all of the time. Mod]
Why the hypothetical? What the OP describes is the situation leading in to the 2007 report. At a quick glance, I can’t see any discussion of it in the synthesis report — they claim 0.2C/decade, even though the short-term trend then was closer to 0.3C/decade, as noted in tamino’s most recent post.
So the answer is (c) they’d just ignore the issue entirely in the summary document.
Seems to me they are saying it even though it did not happen.
what had happened to temperatures in the 15 and 30 years prior to 1984 when Hansen was running his models that said temps were going to increase greatly? iirc, there had only been a short time of slight warming up to that point…
My 2 cents, I think 30 years is a reasonable amount of time to declare a trend. It’s not so short that temporary events throw it off, it’s not so long that we are unable to ever say a tend has occurred.
I take the 15 years without warming as meaning it hasn’t warmed in 15 years, nothing more. We can’t say it’s an indicator of what’s going to happen in the next 15 years.
To make accurate predictions, we need quality models. These we don’t have yet.
Ehem, for now. If it reaches 30 years they will simply extend it as they have already done. Yet some of them seem to be suffering from amnesia the poor souls. Here is the climate clown, Dr. Paul Jones, shouting about global warming of sixteen years being statistically significant. He does go on to say that 20 to 30 years if preferable.
So he prefers 20 to 30 years but agrees that the hiatus is statistically significant.
Off topic
[Yes, it is off-topic. Mod]
One of the big reasons I remain a skeptic is I ask myself — what would they be saying if the exact opposite had occured. For instance, instead of a warming trend, what if the globe was undergoing a cooling trend? Would we be talking about human induced global cooling that will induce global famine and cause more extreme weather events or would we be talking about a short term natrual climate variability? I think it’s very likely the former is true. It seems to me that humans were going to be blamed for anything short of a completely neutral climate. And, if climate didn’t cooperate, something else to progress the environmentalist agenda would have been found. Long after human induced climate change is dead, human activity will still be blamed for something wrong with the environment/planet and more taxes, wealth redistribution and a new list of ‘evironmental sins’ is likely to be the claimed savior.
“15 years” became a benchmark when a climate modeler (I cant remember who) said that thats how long there would need to be no warming to show that the climate models were wrong
jbird says:
October 2, 2013 at 7:10 am
If the IPCC was truly worried about catastrophic anthropogenic global warming, they would greet the news of no warming for the past 15 years with relief rather than excuses.
This.
Have thought exactly the same for years jbird. After all, we’re facing ‘catastrophe’, right? What better news could there possibly be, ever, than Humanity isn’t getting wiped out this weekend? But from the alarmists…..silence.
It exposes their true stance – political, financial, controlling. Nowt to do with climate in the slightest.
If the scenario you describe had happened, we would currently be in the midst of a worldwide depression due to spotty, expensive electricity and only electric cars and trucks in Europe, the US and Japan. The depression in the West would have hurt China, India and the Middle East.
The Chicken Little crowd would have won the political day and succeeded in closing down most of the fossil fuel industry….before the report.
Has anyone else been reading the MSM headlines this week? They have turned all of their attention to attacking and discrediting skeptics in any way they can. These are the dark ages of climate science.
magicjava says:
October 2, 2013 at 7:55 am
My 2 cents, I think 30 years is a reasonable amount of time to declare a trend
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and it took 500 years of a downward trend to reach the bottom of the LIA….
…that is now claimed to be an upward trend
We’re just in a hiccup right now…..
…the overall trend is still down
“What would the IPCC have written if there had been 12 years of rapid warming?”
It would be interesting to speculate on what would WattsUpWithGlobalWarming have written if there had been 12 years of rapid warming.
(Reply: No speculation necessary. There would be no censorship of the data here, as there is by the IPCC. But unfortunately for your beliefs, global warming has stopped, so all you have is your baseless ‘speculation’. ~ mod.)
Is that a typo in the report that says:
“As one example, the rate of warming over the past 12 years (2000–2012; 0.23 [+0.13 to +0.33] °C per decade), which begins after the effect of a strong El Niño disappeared, is bigger than the rate calculated since 1951 (1951–2012; 0.12 [0.08 to 0.14] °C per decade).”
Not one temperature dataset has anything remotely close to +0.23C per decade since 2000. It is also not bigger than the trend from 1951-2012, it is indeed smaller. (roughly +0.07C per decade versus +0.12C per decade)
Strange that the IPCC now want 30 year trends, dismiss any ‘change’ under 30 ears and show in “Figure SPM.1” ‘decadal averages – for visual effect.
For some, 30 years good, 10 years bad, for others, its not so good.
wayne Job says:
October 2, 2013 at 5:47 am
“Some years ago Russian and Ukraine scientists using instruments aboard the Russian part of the International Space Station started monitoring and measuring the sun. They predicted the hiatus in the temperature the hibernation of the sun over coming cycles and a cooling period much like the Maunder minimum. Thus far they have been correct, the next hundred years may be a tad cold. The science boss of the monitoring of the sun is Habibullo I. Abdussamatov. he gives a new take on what controls our temperature. Leif will not be happy.
Funny thing is that the critique of the Abdusamatov is basically unable to point out anything else than the extremely questionable conclusions from Lockwood/Fröhlich2008 (which is more about defending PMOD TSI dataset Fröhlich is author thereof, in the old, irrelevant and likely unresolvable ACRIM/PMOD controversy than anything else) who claim “all solar forcings of climate have declined since 1987” – while the solar indices show quite opposite for another two decades – the SSN (the SIDC-SSN 1965-2005 trend still rising), F10.7 (the 1965-2005 trend still rising) and GCR (the 1965-2005 trends still declining) show quite consistently rising mid-term solar activity trend up until mid 2000’s and only then a relatively sharp swift decline.
Pippen Kool:
At October 2, 2013 at 8:21 am you say
Why? I see no reason or interest in such a speculation.
And who or what is WattsUpWithGlobalWarming?
Please explain.
Richard
I am going to repost a comment from Chris4692 @ur momisugly August 27, 2013 at 6:57 am that documents the falsification criteria.
Off Topic.
Billions / Trillions have been spent on a trace gas boogie man, yet feeble amounts have been allocated to a potential rock slamming into planet earth causing untold damage.
Do we have our priorities in order ladies and gentleman?
IPCC is more politics than science.
The one significant driver of the average global temperature trend since 1610 is disclosed at http://conenssti.blogspot.com/
After about 1895, accurate temperature measurements were made world wide and revealed the natural oscillations above and below the sunspot-number-time-integral-trajectory. The oscillations are caused by the net effect of ocean cycles (which are dominated by the PDO). The resulting graph and physics-based equation that accurately (R2=0.9) calculates the measured anomaly trend are shown at http://climatechange90.blogspot.com/2013/05/natural-climate-change-has-been.html
Gary Pearse says:
October 2, 2013 at 5:48 am
Good observation on Antarctic Ice, but a minor correction;
Antarctic Sea Ice Extents is now setting new record high levels at 19,000,000 sq km’s.
It is Antarctic Sea Ice Area that is greater than 16,000,000 km’s, but as you point out, all of the recent Antarctic sea ice areas over 16,000,000 have occurred in the most recent years.
Equally alarming, the 40 year trend of ALL Antarctic Sea Ice measurements (maximum, average, and minimum extents) continues their steady increases since 1979. At today’s rates of increase in southern sea ice extents, Cape Horn could be closed to ship traffic as soon as 8 to 12 years.
Pippen Kool says:
October 2, 2013 at 8:21 am
It would be interesting to speculate on what would WattsUpWithGlobalWarming have written if there had been 12 years of rapid warming.
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that the LIA was 500 years of rapid cooling…that is now claimed as warming
…and the overall trend is still down
http://wattsupwiththat.com/2009/12/09/hockey-stick-observed-in-noaa-ice-core-data/