I want to explore the Petr Chylek editorial a bit because it contains some key issues for me:
What are the key pillars of man-made global warming theory — or the AGW Dominant Scientific Paradigm?
For me they are:
– anthropogenic CO2 and other greenhouse gasses released in the atmosphere as a result of burning of fossil fuels and land use changes
– increase in concentration of anthropogenic CO2 and other greenhouse gasses released in the atmosphere as a result of burning of fossil fuels and land use changes to levels not seen for hundreds of thousands of years
–enhanced greenhouse effect resulting from increase in concentration of anthropogenic CO2 and other greenhouse gasses released in the atmosphere as a result of burning of fossil fuels and land use changes to levels not seen in hundreds of thousands of years.
– increase in globally average temperature over the past 50 years due to enhanced greenhouse effect resulting from increase in concentration of anthropogenic CO2 and other greenhouse gasses released in the atmosphere as a result of burning of fossil fuels and land use changes to levels not seen in hundreds of thousands of years.
– potentially damaging consequences for human civilization in the future if nothing is done to mitigate increase in globally average temperature over the past 50 years due to enhanced greenhouse effect resulting from increase in concentration of anthropogenic CO2 and other greenhouse gasses released in the atmosphere as a result of burning of fossil fuels and land use changes to levels not seen in hundreds of thousands of years.
I don’t see any of my AGW pillars as being undermined by the CRU emails or the mistake in the AR4 over Himalaya glaciers and 2035/2350. In fact, I think my pillars are still intact.
Let’s see what pillars Chylek thinks have been destroyed or undermined by recent developments:
Here is the excerpt:
Climate research made significant advancements during the last few decades, thanks to your diligent work. This includes the construction of the HadCRUT and NASA GISS datasets documenting the rise of globally averaged temperature during the last century. I do not believe that this work can be affected in any way by the recent email revelations. Thus, the first of the three pillars supporting the hypothesis of man-made global warming seems to be solid. However, the two other pillars are much more controversial.
So, according to Chylek, the CRU emails do not undermine the documented rise in globally averaged temperature during the last century. This is the first pillar supporting the hypothesis of man-made global warming. Glad to know Chylek thinks it’s still intact — many over at CA and WUWT seem to think otherwise, and that the CRU emails show evidence of fraudulent manipulation of the data, thus undermining the globally averaged temperature record.
On to the second:
To blame the current warming on humans, there was a perceived need to “prove” that the current global average temperature is higher than it was at any other time in recent history (the last few thousand years). This task is one of the main topics of the released CRU emails.
Here, we see reference to the whole paleoclimate issue and the “hockey stick” controversy.
Now, correct me if I’m wrong, but before the AR4 and the MBH graph, did or did not climate scientists think that global warming was the result of human emissions of greenhouse gasses?
Why, yes — I believe they did argue that.
Paleoclimate temperature reconstruction, sad to say, is climate science’s poor country cousin. It was seen as a way to verify if current warming was greater or the same — or less than — previous warming in the holocene — the period we are interested in since it is ours. But it ultimately says nothing about the causes and consequences of AGW. And that’s what I’m interested in.
Turns out that the uncertainties in the paleoclimate data are greater the farther back we go — check out the error bars back beyond 1000 CE — we can say little with certainty about the evidence prior to 1,600 according to the NAS report. It may have been warmer, or it may not have been warmer. I don’t think the jury is in. Some research has found that it was as warm or warmer, either regionally or globally, prior to the current warming. Others have replicated the “hockey stick” and have suggested that current warming is greater. Personally, I think it doesn’t really matter much except for measures of climate sensitivity.
I’m even willing to concede that it might have been warmer previously — in the so-called medieval warming period that skeptics and deniers love to bandy about. Ultimately, I have to say “BFD.” What matters to me is the CWP since that’s the one I live in and any potential FWP — future warming period — since that’s where the danger lies.
So yes, MBH methodology (and do you ever notice how everyone always refers to “Mann” and not Bradley and Hughes as if Mann was some overlord browbeating his superiors…) used questionable statistics when it de-centered the PC. Yes, perhaps the de-centered PC analysis did give too much weight to Sheep Mountain data.
The net result? Is climate science dead? Negatory.
The hockey stick isn’t quite so flat any longer, but the blade remains and ultimately, it’s the blade that counts — at least, for us who want to continue enjoying the moderate and relatively stable temperatures of the holocene. After all, it looks like there might be another couple ten-thousand years before we have to worry about the next ice age, right? Lots of time to develop geoengineering schemes or move to other planets.
So the second pillar of man-made global warming is, according to Chylek, the hockey stick and the notion that current warming is greater than any time in the holocene. Chylek seems to suggest without providing a closer examination, that the CRU emails destroys this pillar. I suppose references in the emails to “Mike’s Nature trick” and “hide the decline” took care of that, at least according to denialists around the blogosphere.
But even so, we’re left with that damn temperature record, which Chylek still recognizes as intact. The hockey stick is pretty, but it’s not the beef. I care about the beef.
Onto pillar three:
Some people were soeager to prove this point that it became more important than scientific integrity.The next step was to show that this “unprecedented high current temperature” has to be a result of the increasing atmospheric concentration of carbon dioxide from the burning of fossil fuels.
The fact that the Atmosphere Ocean General Circulation Models are not able to explain the post-1970 temperature increase by natural forcing was interpreted as proof that it was caused by humans. It is more logical to admit that the models are not yet good enough to capture natural climate variability (how much or how little do we understand aerosol and clouds,and ocean circulation?), even though we can all agree that part of the observed post-1970 warming is due to the increase of atmospheric CO2 concentration.
He states that “we can all agree that part of the observed post-1970 warming is due to the increase of atmospheric CO2 concentration” — YAY! Another one of my pillars is confirmed even by a skeptic.
He is unwilling to indict fossil fuel burning as the main culprit. The fact that models could not explain warming in the 20th C without CO2 is not seen as good enough — what he suggests is that the models themselves are not yet adequate to fully model the atmosphere and its complexity and thus, attributing all the warming to CO2 is erroneous.
Now, he has a point, of course. Models are not perfect — but no one credible is claiming they are. Certainty is for journalists and politicians and those who want to make a political point. It is not the parlance of scientists who are more comfortable with uncertainty. From what I have read, climate modelers are always talking about uncertainties — heck, even Dr. Evil Mann included many mentions of uncertainties in his paper on Northern Hemisphere temperature reconstructions…
So from what I can see, climate modelers have always sought to improve their models and have always spoken of uncertainties. Yes, they need to be continuously improved. Yes, CO2 is not solely responsible for the temperature increases in the 20th and 21st centuries. Yes, there are complexities within complexities in the climate and our attempts to model it. Still, we have been pumping a whole lot of anthropogenic greenhouse gas from the burning of fossil fuels into the atmosphere and have succeeded in increasing the concentration of CO2 in the atmosphere from 290 to 390 over the course of a very short time — in geological terms — increased to levels not seen for hundreds of thousands of years.
If we didn’t explore the consequences of this modification of the atmospheric concentration of CO2, and the links between it and enhanced greenhouse effect and current warming, we don’t deserve the title “sapiens”.
Here is Chylek’s parting shot:
Thus, two of the three pillars of the global warming and carbon dioxide paradigm are open to reinvestigation.The damage has been done. The public trust in climate science has been eroded. At least a part of the IPCC 2007 report has been put in question. We cannot blame it on a few irresponsible individuals. The entire esteemed climate research community has to take responsibility. Yes, there always will be a few deniers and obstructionists.
What? Everything is always open to reinvestigation! That’s what science is and does. These two pillars Chylek thinks he and others have proven demolished are not pillars of anything but their own Rube-Goldberg imaginations.
We cannot blame it on a few irresponsible individuals? These deniers and skeptics want it both ways, in my view. They want to vilify a few — Hansen, Jones, Mann, Bradley, Hughes, Briffa, Schmidt, Thompson — am I leaving anyone out? (It would be an interesting content analysis to count up how many times McI and Watt mention these scientists in particular.) They also want to trash the many. I hear reference after reference to climate scientists as if they are a hive mind and are all in on some big “hoax”.
So what comes next? Let us stop making unjustified claims and exaggerated projections about the future even if the editors of some eminent journals are just waiting to publish them. Let us admit that our understanding of the climate is less perfect than we have tried to make the public believe. Let us drastically modify or temporarily discontinue the IPCC. Let us get back to work.
Temporarily discontinue the IPCC.
There — that’s the holy grail, isn’t it? That’s what people like McI and his crew have been working towards and why they have selectively taken it on for “audit”.
I’m sure Steven Milloy is laughing up his sleeve…
So, in my estimation, Chylek succeeded in holding up the most important pillar of his three and proved that the other two were nothing more than strawmen and red herrings. Cute! Two fallacies in one.
Gotta love those skeptics.