Monthly Archives: December 2009

Temperature History

Assuming Your Conclusion

20 Comments

I thought this was pretty interesting, and oh-so typical of climate science, from an article by Viscount Monkton:

The paper was based on a test of a widely-used climate model on the mid-Pleiocene warm period, 3 million years ago, when the Earth warmed in response to natural processes. Cores drilled from ocean sediment provide some evidence for atmospheric carbon levels and temperature at the time.

The team found that at that era, although CO2 levels were close to today’s 388 parts per million by volume, global temperature was 3 C° (5.5 F°) warmer than today. The paper assumes – without evidence – that the difference can only be fully explained by the long-term loss of ice sheets and changes in vegetation that caused the Earth’s surface to absorb more solar radiation. One of the authors said that today’s CO2 concentration of 388 ppmv might already be too high to prevent more than 2 C° (3.5 F°) of warming compared with pre-industrial times – the limit agreed as an aspiration by the recent Copenhagen accord.

The authors are concluding that there is therefore another 3C of warming we should see over time due to our current CO2 levels that has just not showed up yet because slow-response-time feedbacks like ice melting / albedo changes haven’t fully come into play.

I presume you see the problem.  This conclusion can only be drawn if either

1.  We know the value of every other climate forcing that was in play 3 million years ago, and know them to be identical to their values today, such that the only changed variable in the temperature system between then and now is CO2.  Of course, this is absurd — we can’t possibly know all the other forcings from 3 million years ago (we argue about what they are today) and there is a very low probability they were all of the same value as today to set up a nice controlled experiment.  – OR –

2.  We assume that the only major driver of climate, the one that dominates and makes all others irrelevant, is CO2.  This is not only not proven, it is not even reasonably true.

These guys, as is so often the case in climate, are assuming their conclusion.  “If we assume that CO2 is the primary driver of climate, then sensitivity of the climate to CO2 is high.”  Duh.

Other Causes of Warming

Warming and Soot

5 Comments

A while back I advanced the hypothesis that soot was a major driver of sea ice melting in the Arctic.  Black carbon deposits on ice and snow tend to force them to melt much faster by reducing their albedo.  I hypothesized that this might explain why there were record low summer sea ice coverages of late in Arctic sea ice but relatively average winter sea ice extents — black carbon can’t build up in the fall and winter because they are constantly covered with new snow and ice while soot that falls in the summer stays on the surface.

By the way, this would be good news – an anthropogenic effect due to soot is MUCH easier to correct than one due to CO2, as we know how to have a prosperous fossil fuel powered economy without soot but we don’t know how to have one without CO2.

Kevin Lawton has a post correlating past warming with areas that are susceptible to thaws, concluding that black carbon may have a role in past warming.  I have to think about his argument more, but he has some good links to recent work on black carbon and warming.

Effects of Warming

Severe Weather and Anthropogenic Global Warming

14 Comments

As I put together an updated version of my climate movie and powerpoint deck, I am constantly amazed how alarmist claims that man is causing [fill in the blank severe weather] via his CO2 emissions simply never pan out.  I am not saying they don’t pan out because there is no causality proof – that goes without saying.  No one has ever been able to or likely will ever be able to link a specific weather event like Katrina directly to CO2 emissions — but of course that does not stop them from trying and does not prevent a credulous media from lapping it up  (and in fact there is a class action suit as we speak against oil and power companies for “causing” Katrina).

No, what I mean is that the supposed weather trend seldom if ever exists.  What is happening is that alarmists are latching onto individual events in the tail ends of the normal distribution for weather and claiming that these events signal a shift in the mean.  But they never actually publish data for the mean, and there is a reason for that.  Time and time again, with hurricanes, US floods and droughts, severe storms, and tornados, when we look at the data we see no shift in the mean.

Here is a good example form Warwich Hughes.  The Western Australia Premier says back in 2007″

Mr A.J. CARPENTER (WA Premier): “..It has stopped raining in the south west of Western Australia. The rain no longer falls from the sky in sufficient quantities to fill the dams to fill the pipes to fill the cups for people to drink…”

The reality:  A one year drought in 2006 is being used to argue that the mean rainfall has shifted.  It clearly has not.

percatch09

Climate Science Process

Two Completely Different Sets of Rules

24 Comments

In the American Thinker, Davide Douglass and John Christy follow the saga of the publication of one of their papers (referred to in the article as DCPS for its four author’s initials) and a response by Santer, et. al.  To be clear, the DCPS paper was a critique in certain flaws in then-current climate models and how they do or don’t accurately match actual observations, while Santer et. al is a sort of who’s-who of climate alarmist scientists in the inner core who were rallying the troops to defend the mother ship.

The article needs to be read in total to get the gist of the whole sorry story, but it is very clearly a tale of two entirely different publication and review rules — one set for skeptics, and another far more congenial set for alarmists.  I think the article pretty clearly tells the tale of a process tilted strongly against one side in a scientific debate.

I hope you will check it out.  One of my favorite parts is about 2/3 through the story.  Santer et al’s main criticism is that DCPS cherry-picked data sets (basically left one particular set out).  Unlike alarmist cherry-picking, though, DCPS had actually clearly stated why the data set had been left out and referred to other peer-reviewed literature that backed their point.  The Santer team never addressed these reasons, but simply repeated the original charge.  But the rich part is where Santer et al. are uncomfortable using certain parts of the data set themselves that don’t tell their story for them, so they explicitly edit this data out, in a manner very reminiscent of Keith Briffa and his proxy series.  Emails from the CRU demonstrate that this removal was for no good reason other than the data did not make the point they wanted it to make.

The whole thing is really frustrating.  One side is denied information, while the others are spoon fed their opposition’s work in progress nearly every week.  One side’s publication is rushed, while the other’s is delayed.  One side gets to essentially pick its own reviewers, and in an incredible breach, have a prickly reviewer simply removed from the process (again for no good reason than he wasn’t giving the answer they want).  This is like watching the inside mechanics of an election in North Korea.

Temperature History, Temperature Measurement

Defending the Tribe

217 Comments

This is a really interesting email string form the CRU emails, via Steve McIntyre:

June 4, 2003 Briffa to Cook 1054748574
On June 4, 2003, Briffa, apparently acting as editor (presumably for Holocene), contacted his friend Ed Cook of Lamont-Doherty in the U.S. who was acting as a reviewer telling him that “confidentially” he needed a “hard and if required extensive case for rejecting”, in the process advising Cook of the identity and recommendation of the other reviewer. There are obviously many issues involved in the following as an editor instruction:

From: Keith Briffa
To: Edward Cook
Subject: Re: Review- confidential REALLY URGENT
Date: Wed Jun 4 13:42:54 2003

I am really sorry but I have to nag about that review – Confidentially I now need a hard and if required extensive case for rejecting – to support Dave Stahle’s and really as soon as you can. Please
Keith

Cook to Briffa, June 4, 2003
In a reply the same day, Cook told Briffa about a review for Journal of Agricultural, Biological, and Environmental Sciences of a paper which, if not rejected, could “really do some damage”. Cook goes on to say that it is an “ugly” paper to review because it is “rather mathematical” and it “won’t be easy to dismiss out of hand as the math appears to be correct theoretically”. Here is the complete email:

Hi Keith,
Okay, today. Promise! Now something to ask from you. Actually somewhat important too. I got a paper to review (submitted to the Journal of Agricultural, Biological, and Environmental Sciences), written by a Korean guy and someone from Berkeley, that claims that the method of reconstruction that we use in dendroclimatology (reverse regression) is wrong, biased, lousy, horrible, etc. They use your Tornetrask recon as the main whipping boy. I have a file that you gave me in 1993 that comes from your 1992 paper. Below is part of that file. Is this the right one? Also, is it possible to resurrect the column headings? I would like to play with it in an effort to refute their claims. If published as is, this paper could really do some damage. It is also an ugly paper to review because it is rather mathematical, with a lot of Box-Jenkins stuff in it. It won’t be easy to dismiss out of hand as the math appears to be correct theoretically, but it suffers from the classic problem of pointing out theoretical deficiencies, without showing that their improved inverse regression method is actually better in a practical sense. So they do lots of monte carlo stuff that shows the superiority of their method and the deficiencies of our way of doing things, but NEVER actually show how their method would change the Tornetrask reconstruction from what you produced. Your assistance here is greatly appreciated. Otherwise, I will let Tornetrask sink into the melting permafrost of northern Sweden (just kidding of course).
Cheers,
Ed

A couple of observations

  1. For guys who supposedly represent the consensus science of tens of thousands of scientists, these guys sure have a bunker mentality
  2. I would love an explanation of how math can have theoretical deficiencies but be better in a practical sense.  In the practical sense of … giving the answer one wants?
  3. The general whitewash answer to all the FOIA obstructionism is that these are scientists doing important work not to be bothered by nutcases trying to waste their time.  But here is exactly the hypocrisy:  The email author says that some third party’s study is deficient because he can’t demonstrate how his mathematical approach might change the answer the hockey team is getting.  But no third party can do this because the hockey team won’t release the data needed for replication.  This kind of data – to check the mathematical methodologies behind the hockey stick regressions – is exactly what Steve McIntyre et al have been trying to get.  Ed Cook is explaining here, effectively, why release of this data is indeed important
  4. At the very same time these guys are saying to the world not to listen to critics because they are not peer-reviewed, they are working as hard as they can back-channel to keep their critics out of peer-reviewed literature they control.
  5. For years I have said that one problem with the hockey team is not just that the team is insular, but he reviewers of their work are the same guys doing the work.  And now we see that these same guys are asked to review the critics of their work.
Temperature Measurement

Russians Accuse CRU of Cherry-Picking Station Data

15 Comments

Many of us are aware of the cherry-picking of proxy series that goes on in the temperature reconstruction world.  This cherry picking is both manual — a thousand plus proxy series exist but the same 20-30 that are known to create hockey sticks are selected over and over; and algorithmic — McIntyre and McKittrick demonstrated how Michael Mann’s algorithms preferentially put high weights on hockey-stick shaped series.

I think a lot of us has suspected something similar in the surface temperature measurement indexes like the Hadley CRUT3, the main metric relied on by the IPCC.

On Tuesday, the Moscow-based Institute of Economic Analysis (IEA) issued a report claiming that the Hadley Center for Climate Change based at the headquarters of the British Meteorological Office in Exeter (Devon, England) had probably tampered with Russian-climate data.

The IEA believes that Russian meteorological-station data did not substantiate the anthropogenic global-warming theory. Analysts say Russian meteorological stations cover most of the country’s territory, and that the Hadley Center had used data submitted by only 25% of such stations in its reports. Over 40% of Russian territory was not included in global-temperature calculations for some other reasons, rather than the lack of meteorological stations and observations.

So, maybe they were chosen because they had higher quality data with fewer data gaps.  Wrong:

The HadCRUT database includes specific stations providing incomplete data and highlighting the global-warming process, rather than stations facilitating uninterrupted observations.

On the whole, climatologists use the incomplete findings of meteorological stations far more often than those providing complete observations.

Maybe they were urban biases in the data that was excluded. No, just the opposite:

IEA analysts say climatologists use the data of stations located in large populated centers that are influenced by the urban-warming effect more frequently than the correct data of remote stations.

So, without the CRU giving any clear set of decision rules for station selection, we are left with this:

The data of stations located in areas not listed in the Hadley Climate Research Unit Temperature UK (HadCRUT) survey often does not show any substantial warming in the late 20th century and the early 21st century.

I am sure it is the purest coincidence that stations excluded from metrics like this show less warming and proxies excluded from temperature reconstructions don’t look like hockey sticks.

Update: McIntyre here and Watts here.

Climate Science Process

Analyzing the Global Warming Alarmist Phenomenon

283 Comments

Martin Cohen sent me an email with a series of links that all look at global warming alarmism as a phenomenon.

In defence of scepticism

By Martin Cohen, editor of the Philosopher

Climate Hysterians have been redoubling their efforts to portray the debate as one between a few cranks (especailly right-wing ones) and ‘scientists’, whereas the truth is very different.  Here, for example, are just four recent substantial articles challenging climate change science, from a neutral or ‘philosophy of science’ perspective.

1. Professor John David Lewis of Duke University, USA, has challenged many of the claims made by proponents of man-made climate change theory, in an article in the prestigious journal Social Philosophy and Policy (Volume 26 No. 2 Summer 2009), saying: ‘Those predicting environmental disasters today focus on particular issues in order to magnify the gravity of their general claims, and they push those issues until challenges make them untenable. Rhetorical skill and not logical argument has become the standard of success.’

2. In a separate review article, published in the Times Higher on the 03 December 2008, Professor Gwyn Prins, the director of the Mackinder Programme for the Study of Long Wave Events at the London School of Economics, says that the ‘principle product of recent science is to confirm that we know less, less conclusively – not more, more conclusively – about the greatest open systems on the planet’, and goes on to predict that for this reason, the ‘Kyoto Flyer’ is about to hit the buffers at Copenhagen.

3. Professor Mike Hulme’s defence of scepticism in the December Wall Street Journal:

http://online.wsj.com/article/SB10001424052748704107104574571613215771336.html

4. And (last but not least!) my own feature article ‘Beyond Debate?’, is in the current (10 December 2009, and not on the website, timeshighereducation.co.uk until that date – but well worth a look!) issue of the scuprlously neutral Times Higher Education. None of these accounts are motivated by either improper influence or a right-wing agenda. As my article explains, climate change lobbyists such as Al Gore (and now Gordon Brown!) are:

* Using images, such as the polar bears supposedly trapped on a melting iceberg, ships in a dried up sea as crude propaganda to appeal to people?s fears rather than their reason.

* Presenting irrelevant ‘data’, such as unusual weather events of high summertime temperatures, as though these were connected to the main climate change hypotheses, of carbon dioxide trapping heat, even though this theory in fact only concerns night-time temperatures. All these articles point out that the supposed causal link between carbon dioxide levels and temperatures has no historical basis, and relies instead on computer models that have been shown to be unreliable and misleading. It says that if, for those at, the Copenhagen summit, the idea of manmade global warming is incontrovertible, the consensus is less a triumph of science and rationality than of PR and fear- mongering.

The full text is at:

http://www.timeshighereducation.co.uk/story.asp?sectioncode=26&storycode=409454&c=2

Temperature History

Powers of 10

10 Comments

This is a really interesting post at WUWT by J. Storrs Hall. It reminds me of one of those powers of ten films. He looks at data from a Greenland ice core (archived at NOAA here) going back over 50,000 years.   He begins looking at the last few hundred years, and then pulls back the view on larger and large time scales.  Highly recommended.

Note: Box, et al in 2009 claim to have found from 1-1.5C of warming since around 1900 when this chart leaves off.  It is very, very , very dangerous to splice data sets together, but one probably has to add a degree or so to the tail of the chart to bring it up to date, putting current warming about at the Medieval level but below earlier Holocene temperatures.

Temperature Measurement

Urban Biases on Surface Temperature Records

39 Comments

I apologize to readers who visit both of my sites for the repetition between them of late, but there is a lot of demand in the community of folks who usually don’t come to climate sites for climate analysis, so I am repeating stuff from here at my other blog.

A kid and his dad manage to do the analysis that NASA, the EPA, the CRU, and the IPCC can’t be convinced to perform. Awesome.

Climate Science Process

Incentives and Conspiracies

16 Comments

Cross-posted from Coyote Blog:

I am sort of the anti-conspiracy theorist. I have written a number of times that events people sometimes explain as orchestrated conspiracies often can be explained just as well by assuming that people with similar preferences and similar information and similar incentives will respond to these incentives in similar ways.

I think the great herd-think around climate alarmism is a good example, and the Bishop Hill blog brings us a specific illustration from the comment section of Watts Up With That. A commenter observed that it was pretty hard to believe that thousands of scientists could be participating in a conspiracy. Another commenter wrote back:

Actually not so hard.

Personal anecdote:
Last spring when I was shopping around for a new source of funding, after having my funding slashed to zero 15 days after going public with a finding about natural climate variations, I kept running into funding application instructions of the following variety:

Successful candidates will:
1) Demonstrate AGW [ed: Anthropogenic Global Warming]
2) Demonstrate the catastrophic consequences of AGW.
3) Explore policy implications stemming from 1 & 2.

Follow the money — perhaps a conspiracy is unnecessary where a carrot will suffice.

If only alarmist results are funded, then it should not be surprising that only alarmist studies are produced.

By the way, it is probably incorrect to think of climate science really being driven by 2500 scientists. Here is an analogy: Strategy at General Motors is in some sense driven by thousands of workers – salesmen who know the market, channel managers who know their distribution partners, planners who watch econometric trends, manufacturers who know what can and can’t be done with costs, engineers who see what the next technological opportunities, etc. — you get the idea.

But realistically, there are probably 20-25 people who are really setting and driving and communicating the corporate strategy for GM. And those 20-25 people will likely say to the public that their strategy is supported by all those 200,000 workers. But in fact there are thousands, maybe even a majority, that would say that they don’t support the strategy and don’t think that strategy is consistent with their bit of knowlege.

I think climate science works roughly the same way. The same 20-25 people are lead authors on the IPCC, write key reports, contribute to Al Gore’s movie, get quoted in the NY Times, run the Realclimate web site, and, of course, feature prominently in the CRU emails. And while these 25 may claim thousands of scientists support their conclusions based on the mere fact that these other scientists contributed to an IPCC report that had these conclusions, many of these scientists, when actually asked, will disagree.

Here is one thing that is never mentioned — most of the scientists outside of climate science who have gone on the record somewhere as supporting catastrophic man-made global warming theory, if you really talked to them, would say they made their statement in support of science, not global warming theory. Most of these folks really haven’t dug into the details, but the problem was presented to them as one of science vs. anti-science. They are told by their peers and the media that AGW skeptics are all fundamentalist super right-wing anti-science evolution deniers who think the Earth is 4000 years old.

By saying they support AGW, these scientists are really trying to make the statement that they support science. The bitter irony is that they are doing the opposite, enabling those in the core of the climate community who are trying to duck criticism and replication by demanding unquestioning respect for their authority. The fact is that nearly every time one of these outsider scientists – a physicist or a geologist or a statistician, say – digs into the science, they are appalled at what they find and how bad the science behind catastrophic AGW theory really is.

Skeptic Summaries

Why the Historical Warming Numbers Matter

28 Comments

This is cross-posted from my non-climate blog.  I wrote it for folks who spend less time on the science-based skeptic sites, but I had several folks tell me that it would still be useful to post here.

First, let’s settle something. The world has warmed since 1850. While there always is an error bar on nearly every statement about nature, I think there is little point in questioning this past warming. There is ice core data that suggests that the little ice age, which ended some time in the very early 19th century, was perhaps the coldest period, or one of the two or three coldest periods, in the last 5000 years (ie in nearly the entire span of human civilization). Temperatures are inevitably warming from this low point.(*1)

So, if the point is not to deny warming altogether, what is the point in discussions of Climategate of picking over and trying to audit historical temperature records like the Hadley CRUT3 or NASA’s GISStemp? Skeptics often argue that much of the warming is due to bogus manual adjustments in the temperature records and biases such as urban warming. Alarmists argue that the metrics may understate warming because of masking by manmade anthropogenic cooling agents (e.g. sulfate aerosols). Why bother? Why does it matter if past warming is 0.6C or 0.8C or 0.3C? There are at least two reasons.

1. The slope of recent temperature increases is used as evidence for the anthropogenic theory.

We know greenhouse gasses like CO2 have a warming effect in the lab. And we know that overall they warm planets because otherwise ours would be colder. But how much does an incremental amount of CO2 (a relatively weak greenhouse gas) warm the Earth? A lot or a little? Is the sensitivity of the climate to CO2 high or low?

Every time I try to express this, it sounds so ridiculous that people think I must have it wrong. But the main argument supporting a high climate sensitivity to CO2 is that scientists claim to have looked at past warming, particularly from 1950-2000, and they can’t think of any natural cause that could behind it, which leaves CO2 by process of elimination. Yeah, I know this seems crazy – one wants to ask if this is really a test for CO2 sensitivity or of scientists’ understanding and imagination, but there you have it.

Now, they don’t always say it this directly. What they actually say is that they ran their climate models and their climate models could not produce the warming from 1950-2000 with natural forcings alone, but could reproduce this warming with forcings from CO2. But since the climate models are not handed down from the gods, but programmed by the scientists themselves to represent their own understanding of the climate system, in effect this is just a different way of saying what I said in the previous paragraph. The climate models perform the function of scientific money laundering, taking an imperfect knowledge on the front end and somehow converting that into settled science at the output.

Now, there are a lot of ways to criticize this approach. The models tend to leave out multi-decadal ocean cycles and don’t really understand cloud formation well. Further, the period from 1957-2008, which supposedly can only be explained by non-natural forcings, has almost the exact same temperature profile and increase as the time from 1895-1946, which of necessity must be mostly “natural.” I go into this more here, among other places.

But you can see that the amount of warming matters to this argument. The more the warming falls into a documented natural range of temperature variation, the harder it is to portray it as requiring man-made forcings to explain. This is also the exact same reason alarmist scientists work so hard to eliminate the Medieval Warm Period and little ice age from the temperature record. Again, the goal is to show that natural variation is in a very narrow range, and deviations from this narrow range must therefore be man-made. (*2)

This is the sort of unified field theory of everything we are seeing in the CRU emails. We see scientists using every trick they can find to lower or smooth out temperatures numbers before 1950, and adjust numbers after 1950 upwards. Every single trick and programming adjustment all tended to have this effect, whether it be in proxy studies or in the instrumental record. And all the efforts to prevent scrutiny, ignore FOIA’s, and throw out raw data have been to avoid third party replication of the statistical methods and adjustments they used to achieve these ends.

As an aside, I think it is incorrect to picture this as a SPECTRE-like cabal scheming to do evil. These guys really, really believed they had the right answer, and these adjustments were made to tease out what they just knew the right answer to be. This is why we are only going to see confused looks from any of these guys – they really, really believed they were doing God’s work. They are never going to understand what they did wrong. Which doesn’t make it any less bad science, but just emphasizes that we are never going to get data without spin until total sunlight is brought to this process

2. It is already really hard to justify the huge sensitivities in alarmist forecasts based on past warming — if past warming is lower, forecasts look even more absurd.

The best way to illustrate this is with a few charts from my most recent climate presentation and video. We usually see warming forecasts by year. But the real relationship is between warming and CO2 concentration (this relationship is called climate sensitivity). One can graph forecasts at various levels:

Slide57

The blue line corresponds to the IPCC no-feedback formula that I think originally goes back to Michael Mann, and yields about 1-1.2C of warming for greenhouse gas warming from CO2 before feedback effects. The middle two lines correspond to the IPCC mid and high forecasts, and the top line corresponds to more alarmist forecasts from folks like Joe Romm who predict as much as 8-10C of warming by 2100 (when we will be at 650-800ppm CO2 per the IPCC). By the way, the IPCC does not publish the lines above the blue line, so I have taken the formula they give for the blue line and scaled it to meet their end points. I think this is reasonable.

A couple of things – all climate models assume net positive feedback, what skeptics consider the key flaw in catastrophic global warming theory. In fact, most of the catastrophe comes not from global warming theory, but by this second theory that the Earth’s temperature system is dominated by very high positive feedback. I illustrate this here. The blue line is from CO2 greenhouse gas warming. Everything above it is from the multiplier effects of assumed feedbacks.

Slide21

I won’t go into the feedback issue much now – search my site for positive feedback or else watch my video for much more. Suffice it to say that skeptics consider the feedback issue the key failure point in catastrophic forecasts.

Anyway, beyond arguing about feedbacks, there is another way to test these forecasts. Relationships that hold for CO2 and warming in the future must hold in the past (same Earth). So lets just project these lines backwards to the CO2 level in the late 19th century.

Slide61

Can you see the issue? When projected back to pre-industrial CO2 levels, these future forecasts imply that we should have seen 2,3,4 or more degrees of warming over the last century, and even the flawed surface temperature records we are discussing with a number of upwards biases and questionable adjustments only shows about 0.6C.

Sure, there are some time delay issues, probably 10-15 years, as well as some potential anthropogenic cooling from aerosols, but none of this closes these tremendous gaps. Even with an exaggerated temperature history, only the no feedback 1C per century case is really validated by history. And, if one assumes the actual warming is less than 0.6C, and only a part of that is from anthropogenic CO2, then the actual warming forecast justified is one of negative feedback, showing less than 1C per century warming from manmade CO2 — which is EXACTLY the case that most skeptics make.

Those who control the past control the future. Those who control the present control the past.– George Orwell

Footnotes:

(1) More than once I have contemplated how much the fact that the invention of the thermometer occurred at perhaps the coldest point in human memory (early 17th century) has contributed to the perceptions of current warm weather being unusual.

(2) For those who are on the ball, perhaps you can spot an amazing disconnect here. Scientists claim that the natural variation of temperatures is in a very narrow band, that they never move even 0.2C per decade by natural means. But they also say that the Earth’s temperature system is dominated by positive feedback, meaning that very very small changes in forcings are magnified many fold in to large temperature changes. I won’t go in to it in depth from a systems perspective, but trust me that “high stability in a narrow range” and “dominated by high positive feedback” are not very compatible descriptions of a system.

Temperature Measurement

Example #3 of the Need for Replication: Temperature Station Adjustments

4 Comments

I have written a number of times about what appear to be arbitrary or extreme manual adjustments to surface temperature records.  These adjustments are typically positive (ie they make the temperature trend more positive) and often their magnitude outweighs the underlying temperature signal being measured, raising serious issues about the signal to noise ratio in temperature measurement.  Willis Eschenbach on Anthony Watts’ site brings us one of the most extreme examples I have seen, this time from Australia.

I will leave it to you to click through for the whole story, but here are graphs of the Darwin temperature station before and after adjustments.  First the raw data (this, by the way, is what the CRU so famously threw out, so we can’t do this analysis for CRU adjustments)

darwin_zero5

I would be willing to believe the splice-discontinuity around 1940 is an artifact of the data, and one might either throw out the data before 1940 or re-zero it consistent with later data.  Or it might be real.  We really don’t know, we can only guess.  We need to be careful how frequently we guess, as each guess corrupts the data, no matter how much we are trying to improve things.    We might get clues from other nearby thermometers, which is discussed in the article, but thermometers are few and far between in 1920’s Australia.

The other guess we might make is looking around the town of Darwin, seeing the growth of the urban area, we might want to adjust current temperatures down a bit to correct for the urban heat island effect.  Again, we have to be careful, because we are just guessing.

Here is what the GHCN actually does to adjust the data. The black line is the amount manually added to temperatures, resulting in the red line.

darwin_zero7

Wow! Instant global warming.  We’ve suddenly added 2C per century to the Darwin warming trend.

So, why does the black line look like this?  We don’t know, because climate scientists play these games in secret and claim that anyone trying to audit their fine work is just distracting them from more weighty pursuits.   Nominally, the GHCN claims the adjustments are based on comparisons with other local thermometers, but there are not other local thermometers in their data base and the closest ones (hundreds of kilometers away) do not display any behavior that might justify this adjustment.

It is time that we demand the ability to audit and replicate these adjustments.

Climate Science Process

Example #2 Of Work That Needs To Be Replicated: Dendroclimatology

12 Comments

For anyone who has paid attention, the dendroclimatology field has been rife with bad practices for years – cherry picking data sets, hiding modern data that shows “the wrong answer,” using bizarre statistical approaches, flipping data sets upside down, and utter resistance to data requests and any attempts at replication.   Most of the really damning CRU emails are about various dendroclimatology studies, and Keith Briffa, lead author of this section of the last IPCC report, is right in the middle of it all.

The Bishop Hill blog has the story of Briffa’s Yamal data set that has many of these elements.  I have been following this story for years at Steve McIntyre’s blog, but this is a very readable narrative.  It will really put a lot of what in in the CRU emails in context.  I highly recommend it.  Seriously.  In fact, I would go read some of John Holdren’s testimony in front of Congress on Climategate first, then read the Bishop Hill piece to get a sense for the whitewash.

Postscript: I have to laugh — when you see insiders in the alarmist community discussing the resistance to data sharing that really has no excuse, the excuse they use nonetheless among themselves to salve their conscience is the meme that “the FOIA’s were meant to be just harassing them and aimed at reducing the time they had to do real work” — ie they were (as the meme goes with skeptics) based on anti-science rather than any real desire to do science.

Here are a couple of bits from the Bishop Hill piece.

Meanwhile, however, McIntyre could begin to look at what Briffa had done elsewhere. It was not to be plain sailing. For a start, Briffa had archived data in an obsolete data format, last used in the era of punch-cards. This was inconvenient, and apparently deliberately so, but it was not an insurmountable problem — with a little work, McIntyre was able to move ahead with his analysis. Briffa had also thrown a rather larger spanner in the works though: while he had archived the tree ring measurements, he had not supplied any metadata to go with it — in other words there was no information about where the measurements had come from. All there was was a tree number and the measurements that went with it. However, McIntyre was well used to this kind of behaviour from climatologists and he had some techniques at hand for filling in some of the gaps….

Eventually, though, Briffa’s hand was forced, and in late September 2009, a reader pointed out to McIntyre that the remaining data was now available. It had been quietly posted to Briffa’s webpage, without announcement or the courtesy of an email to Mcintyre. It was nearly ten years since the initial publication of Yamal and three years since McIntyre had requested the measurement data from Briffa. Now at last some of the questions could be answered.

Climate Science Process

25, Not 2500

8 Comments

I am going to violate my own rule for one post.  I council everyone I know not to get pulled into the absolutely pointless activity of engaging in dueling headcounts of scientists in the climate debate.  This has zero utility, and means virtually nothing.  Science is not settled like a football game, or an election.

But since I keep getting the “2500” scientists number thrown at me by alarmists, I am starting to believe the number is closer to 25, not 2500.  Sure there are many folks who have participated in work that has become a part of the IPCC, but it is old news that though those folks are counted as believers, many reject key aspects of the IPCC findings.  It is becoming increasingly clear than when people talk about the consensus, it is a position being espoused and communicated and driven by a handful of folks over and over in different outlets.  The same folks were advisors on Gore’s movie and run Realclimate and are advisors of the President and  were leaders of the IPCC process and were featured in many of the CRU emails.

Myron Ebell has an interesting article on this:

But when asked about some of his own extreme statements and predictions, Holdren replied that scientific research had moved on from the latest UN assessment report in 2007. The most up-to-date scientific research was contained in a report written by some of the world’s leading climate scientists and released last summer. Holdren mentioned and referred to this report, Copenhagen Diagnosis, several times during the course of the hearing….

I’m sure it will come as a shock that the two groups largely overlap. The “small group of scientists” up to their necks in Climategate include 12 of the 26 esteemed scientists who wrote the Copenhagen Diagnosis. Who would have ever guessed that forty-six percent of the authors of Copenhagen Diagnosis belong to the Climategate gang?  Small world, isn’t it?

The existence of this small core does nothing to prove or disprove catastrophic anthropogenic global warming.  The same statement about, say, string theory could be made about thousands of scientists working around the margin of the problem but a handful driving the train.  But it does mean that the CRU email scandal is not an irrelevant sideshow involving less than 1% of the climate community — it is a window on poor scientific profess engaged in by a group that makes up perhaps a third or half of the core driving the “consensus”.  Which makes it a big deal.

Temperature Measurement

Example of Climate Work That Needs to be Checked and Replicated

30 Comments

When someone starts to shout “but its in the peer-reviewed literature” as an argument-ender to me, I usually respond that peer review is not the finish line, meaning that the science of some particular point is settled. It is merely the starting point, where now a proposition is in the public domain and can be checked and verified and replicated and criticized and potentially disproved or modified.

The CRU scandal should, in my mind, be taken exactly the same way. Unlike what more fire-breathing skeptics have been saying, this is not the final nail in the coffin of catastrophic man-made global warming theory. It is merely a starting point, a chance to finally move government funded data and computer code into the public domain where it has always belonged, and start tearing it down or confirming it.

To this end, I would like to share a post from year ago, showing the kind of contortions that skeptics have been going through for years to demonstrate that there appear to be problems in key data models — contortions and questions that could have been answered in hours rather than years if the climate scientists hadn’t been so afraid of scrutiny and kept their inner workings secret. This post is from July, 2007. It is not one of my most core complaints with global warming alarmists, as I think the Earth has indeed warmed over the last 150 years, though perhaps by less than the current metrics say. But I think some folks are confused why simple averages of global temperatures can be subject to hijinx. The answer is that the averages are not simple:

A few posts back, I showed how nearly 85% of the reported warming in the US over the last century is actually due to adjustments and added fudge-factors by scientists rather than actual measured higher temperatures. I want to discuss some further analysis Steve McIntyre has done on these adjustments, but first I want to offer a brief analogy.

Let’s say you had two compasses to help you find north, but the compasses are reading incorrectly. After some investigation, you find that one of the compasses is located next to a strong magnet, which you have good reason to believe is strongly biasing that compass’s readings. In response, would you

  1. Average the results of the two compasses and use this mean to guide you, or
  2. Ignore the output of the poorly sited compass and rely solely on the other unbiased compass?

Most of us would quite rationally choose #2. However, Steve McIntyre shows us a situation involving two temperature stations in the USHCN network in which government researchers apparently have gone with solution #1. Here is the situation:

He compares the USHCN station at the Grand Canyon (which appears to be a good rural setting) with the Tucson USHCN station I documented here, located in a parking lot in the center of a rapidly growing million person city. Unsurprisingly, the Tucson data shows lots of warming and the Grand Canyon data shows none. So how might you correct Tucson and the Grand Canyon data, assuming they should be seeing about the same amount of warming? Would you

average them, effectively adjusting the two temperature readings

towards each other, or would you assume the Grand Canyon data is cleaner

with fewer biases and adjust Tucson only? Is there anyone who would not choose the second option, as with the compasses?

The GISS data set, created by the Goddard Center of NASA, takes the USHCN data set and somehow uses nearby stations to correct for anomalous stations. I say somehow, because, incredibly, these government scientists, whose research is funded by taxpayers and is being used to make major policy decisions, refuse to release their algorithms or methodology details publicly. They keep it all secret! Their adjustments are a big black box that none of us are allowed to look into (and remember, these adjustments account for the vast majority of reported warming in the last century).

We can, however, reverse engineer some of these adjustments, and McIntyre does. What he finds is that the GISS appears to be averaging the good and bad compass, rather than throwing out or adjusting only the biased reading. You can see this below. First, here are the USHCN data for these two stations with only the Time of Observation adjustment made (more on what these adjustments are in this article).
Grand_12

As I said above, no real surprise – little warming out in undeveloped nature, lots of warming in a large and rapidly growing modern city. Now, here is the same data after the GISS has adjusted it:

Grand_15

You can see that Tucson has been adjusted down a degree or two, but Grand Canyon has been adjusted up a degree or two (with the earlier mid-century spike adjusted down). OK, so it makes sense that Tucson has been adjusted down, though there is a very good argument to be made that it should be been adjusted down more, say by at least 3 degrees**. But why does the Grand Canyon need to be adjusted up by about a degree and a half? What is biasing it colder by 1.5 degrees, which is a lot? The answer: Nothing. The explanation: Obviously, the GISS is doing some sort of averaging, which is bringing the Grand Canyon and Tucson from each end closer to a mean.

This is clearly wrong, like averaging the two compasses. You don’t average a measurement known to be of good quality with one known to be biased. The Grand Canyon should be held about the same, and Tucson adjusted down even more toward it, or else thrown out. Lets look at two cases. In one, we will use the GISS approach to combine these two stations– this adds 1.5 degrees to GC and subtracts 1.5 degrees from Tucson. In the second, we will take an approach that applies all the adjustment to just the biases (Tucson station) — this would add 0 degrees to GC and subtract 3 degrees from Tucson. The first approach, used by the GISS, results in a mean warming in these two stations that is 1.5 degrees higher than the more logical second approach. No wonder the GISS produces the highest historical global warming estimates of any source! Steve McIntyre has much more.

** I got to three degrees by applying all of the adjustments for GC and Tucson to Tucson. Here is another way to get to about this amount. We know from studies that urban heat islands can add 8-10 degrees to nighttime urban temperatures over surrounding undeveloped land. Assuming no daytime effect, which is conservative, we might conclude that 8-10 degrees at night adds about 3 degrees to the entire 24-hour average.

Postscript: Steve McIntyre comments (bold added):

These adjustments are supposed to adjust for station moves – the procedure is described in Karl and Williams 1988 [check], but, like so many climate recipes, is a complicated statistical procedure that is not based on statistical procedures known off the island. (That’s not to say that the procedures are necessarily wrong, just that the properties of the procedure are not known to statistical civilization.) When I see this particular outcome of the Karl methodology, my mpression is that, net of the pea moving under the thimble, the Grand Canyon values are being blended up and the Tucson values are being blended down. So that while the methodology purports to adjust for station moves, I’m not convinced that the methodology can successfully estimate ex post the impact of numerous station moves and my guess is that it ends up constructing a kind of blended average.

LOL. McIntyre, by the way, is the same gentleman who helped call foul on the Mann hockey stick for bad statistical procedure.

Temperature History

A Total Bluff

32 Comments

Gavin Schmidt has absolutely no evidence for this:  (via Tom Nelson)

Gavin [Schmidt],

In your opinion, what percentage of global warming is due to human causes vs. natural causes?

[Response: Over the last 40 or so years, natural drivers would have caused cooling, and so the warming there has been (and some) is caused by a combination of human drivers and some degree of internal variability. I would judge the maximum amplitude of the internal variability to be roughly 0.1 deg C over that time period, and so given the warming of ~0.5 deg C, I’d say somewhere between 80 to 120% of the warming. Slightly larger range if you want a large range for the internal stuff. – gavin]

This is a complete bluff.  There is no way he or anyone else knows this.  I could reverse his numbers and say 0-20% for CO2 and have just as much justification (actually more, see below).  We have devised no good way to parse the temperature changes into any reliable division between various drivers given the complexity of climate.  The only way climate scientists claim to do it is with their highly flawed temperature models, which is a fit of hubris that is unfathomable.

But, beyond the fact that he simply can’t know the answer, his guess here is just awful.  It does not reality check at all.   Here are a few pointers:

1.  Over the last 40 years, or at least over the portion from 1975-1995 when we saw most of the temperature increase, the sun was at its most active this century, as measured by sunspot numbers.  The PDO, which has close links to temperature, was in its warm cycle.  We likely were continuing to see long-term cyclical recovery from the little ice age.  And anthropogenic land use changes were increasing both urban and rural temperatures.  But he claims that the net effect of non-CO2 factors would have been negative?  This is roughly equivalent to Obama’s jobs claims numbers, saying that he saved jobs that would otherwise have been lost.  It’s appeal is that it makes a useful political point while being impossible to prove.

2.  Hansen is basically repeating the IPCC position that there could be no possible natural explanation for the the 0.2C per decade temperature increases from 1975-2000  — ie that such a pace of temperature increase has to be due to CO2 alone (80-120% in my mind equates to CO2 alone).  But world temperatures increased from 1910 to 1940 by 0.2C per decade, in a period almost certainly only minimally influenced by CO2  (see below).  So natural effects can cause warming in the 1930’s but not in the 1980’s because, why?

temperature-chart1

I often use this chart with audiences:

slide48

3.  I am positive that Hansen would argue that natural effects are currently (and temporarily) canceling out some of the warming.  He would say this as a way to deflect criticism that the world has stopped warming over the last decade (something the CRU emails admit they don’t understand, though they won’t admit this publicly**).  But Hansen et al. think we should be seeing 0.2C a decade or more in CO2 warming that is apparently being overcome by natural effects.  So natural effects have enough variability to cancel out 0.2C of warming but not enough to cause 0.2C of warming?  Huh?

This is sort of a special theme this week on this blog, as the topic keeps coming up.  In short, climate scientists need the climate to be alternately sensitive and insensitive, unstable and stable, driven by nature and not driven by nature, all depending on the period they are trying to explain.   All these wildly contradictory assumptions are required to try to keep the hypothesis of very high sensitivities to CO2 alive.

Here, by the way, was my attempt to explain the last 100 years of temperature with a cyclical wave plus a small linear trend:

slide53

Not bad, huh?  Here is a similar analysis using a linear trend plus the PDO

slide54

My answer seems at least as plausible as Gavin’s.  Here is where I did this analysis in more depth. If I really had an official climate scientist decoder ring, I would blame the gap between measured temperatures and my simplified model in orange during the 1980’s on aerosols.  I don’t know how much if any they affect the climate, but neither do climate scientists and that does not stop them from using it as the universal model plug to improve historic correlations.

By the way, for reference, here is the sunspot cycle:

slide51

Here is the world temperature graph overlayed with the PDO

slide52

And finally here is some evidence (from ice core analysis) that we may just still be recovering from a period that could well have been the coldest period in the last 5000 years  (notice the regular millennial trend as well).

slide50

But CO2 explains 80-120% of the warming?  The time is hopefully coming when smart people stop taking such statements on faith and demand proof.

**Postscript-  Last year I attended a fantastic series of lectures and discussions at ASU called the Origins Conference.  One thing that I observed there was the scientists, in talking about things like the origins of the universe, were quick to admit where they didn’t understand things — in fact they sort of were gleeful about it, like something that they didn’t understand was a new toy under the Christmas tree.  And for real scientists, I suppose it is.  This is not at all what we see in the CRU emails.

Skeptic Summaries

Missing the Main Arguments

44 Comments

Are skeptic’s really bad at making their case.  Or are warming alarmists purposely avoiding the skeptic’s best arguments?  That’s the question I am left  with after reading this Scientific American article supposedly shooting down the skeptic’s best 7 arguments.   Let’s walk very briefly through all seven.  If you don’t want to go through these individually, I will preview the ending or you can skip to it:  None of these seven include any of the most powerful or central arguments of skeptics.  At the end of this article I offer seven competing skeptics claims that never seem to get addressed.

Claim 1: Anthropogenic CO2 can’t be changing climate, because CO2 is only a trace gas in the atmosphere and the amount produced by humans is dwarfed by the amount from volcanoes and other natural sources. Water vapor is by far the most important greenhouse gas, so changes in CO2 are irrelevant.

I have never really relied on this argument, so I am not going to bother with this one.

Claim 2: The alleged “hockey stick” graph of temperatures over the past 1,600 years has been disproved. It doesn’t even acknowledge the existence of a “medieval warm period” around 1000 A.D. that was hotter than today is. Therefore, global warming is a myth.

Without digging into the detail of proxies and statistical methods, it is nearly impossible to discuss the hockey stick in 3 paragraphs.  But in the end it doesn’t matter because the author and I agree that it doesn’t matter.  The author writes:

But hypothetically, even if the hockey stick was busted… what of it? The case for anthropogenic global warming originally came from studies of climate mechanics, not from reconstructions of past temperatures seeking a cause. Warnings about current warming trends came out years before Mann’s hockey stick graph. Even if the world were incontrovertibly warmer 1,000 years ago, it would not change the fact that the recent rapid rise in CO2 explains the current episode of warming more credibly than any natural factor does—and that no natural factor seems poised to offset further warming in the years ahead.

Leaving off the very end, where he goes sailing into the aether by saying incontrovertibly that the rise in CO2 explains our current episode of warming, he says that the hockey stick isn’t really evidence at all, no matter what it says.  I agree.  But skeptics weren’t the ones who brought it up as relevant evidence, the alarmists did.  If they are walking away from it, fine.  [By the way, this is an absolutely core technique of climate science – defend a flawed analysis like a mother bear, claim it is the smoking gun that proves everything, and then when forced to finally accept that it is flawed say that it doesn’t matter.]

Claim 3: Global warming stopped a decade ago; the earth has been cooling since then.

His answer here is really an amazing bit of cognitive dissonance.   He writes:

Anyone with even a glancing familiarity with statistics should be able to spot the weaknesses of that argument. Given the extended duration of the warming trend, the expected (and observed) variations in the rate of increase and the range of uncertainties in the temperature measurements and forecasts, a decade’s worth of mild interruption is too small a deviation to prove a break in the pattern, climatologists say….

If a lull in global warming continues for another decade, would that vindicate the contrarians’ case? Not necessarily, because climate is complex.

So even a 20 year lack of warming does not disprove that CO2 is causing 0.2C – 0.25C per decade of warming or more, because natural variations could mask this or offset it somehow (offsetting therefore as much as 0.5C by natural variation in the cooling direction over two decades).

Some might ask, can’t the warming be hiding or taking some time off?  First, if the theory is right, it can’t be taking time off.  It has to warm, year in and year out.  It can hide in the deep oceans, but new technologies like the ARGO floats since 2002 have shown no increase in ocean heat content in the 6-7 years.  This is why scientists are stuck positing there is some natural phenomenon offsetting the heating with cooling.

But here is the problem, not that any warming scientists are honest enough to raise it.  Their entire argument that recent warming has been driven by CO2 (as the author confidently asserted above) is that scientists are unable to explain the warming since 1950 any other way (ie it can’t be explained by natural factors).  Leave aside that this assertion is based solely on runs of their flawed models – we will get to that later.  Look at the temperature curve for the past decades:

temperature-chart

From this we see two things.  First, warming since 1950 really means warming since about 1975-1980, since there was a flat period before that.  And, this warming over the two decades of the 80’s and 90’s was between 0.4 and 0.5C.

So, do you see the problem?  The entire foundation of global warming alarmism is based on the fact that their computer models can’t imagine anything natural that would warm things by as much as 0.4-0.5C over two decades.  But now, to save the theory, they are positing that there are natural cooling effects that will offset 0.4-0.5C over two decades.   Either natural effects can move temperatures a half degree over two decades or they can’t  (by the way, if you want a hint, look at 1910-1940, where temperatures moved 0.6C over three decades long before man put much CO2 in the air.)

Claim 4: The sun or cosmic rays are much more likely to be the real causes of global warming. After all, Mars is warming up, too.

A couple of issues here.  First, here is a great example of assuming your conclusion.

The IPCC notes that between 1750 and 2005, the radiative forcing from the sun increased by 0.12 watts/square-meter—less than a tenth of the net forcings from human activities [pdf] (1.6 W/m2).

Skeptic’s think that the net forcing numbers from human activities are over-stated, mainly due to over-assumptions of positive feedback effects.  Rather than address this issue, he just assumes the forcing number is right and then says this “proves” skeptics are wrong.

He goes on to say that Svensmark’s cosmic ray theory of cloud formation is not well proven.  I would agree with him that it is a formative theory and needs a lot more evidence and authentication before I am ready to say it represents how the world works.  Which is one reason you will see me sometimes reporting on updates on his theory but you won’t find it in my core arguments on the topic.

But the interesting thing to me is that all the arguments the author makes against Svensmark could equally well apply to anthropogenic greenhouse gas warming theories.  Both have been demonstrated in the laboratory, but it is unclear how either works in the complex climate system.  Both have a few correlations going for it historically, but no smoking gun of causation.  It is interesting the asymmetry of skepticism applied to Svensmark’s evidence vs. that of CO2 warming.

Claim 5: Climatologists conspire to hide the truth about global warming by locking away their data. Their so-called “consensus” on global warming is scientifically irrelevant because science isn’t settled by popularity.

*Shrug* Ad hominem argument, don’t really care. I have tried to be careful in all the CRU email flap to be clear that the substantial failures of scientific process don’t prove or disprove anything – they just mean that the science is not as settled as has been portrayed and that we need more transparency to let the evidence get battle-tested. I personally think a lot of it will collapse, but we actually have to still disprove it — just because it came from unethical folks does not make it wrong, any more than guys who took money from Exxon 20 years ago are automatically wrong either.

Claim 6: Climatologists have a vested interest in raising the alarm because it brings them money and prestige.

I actually think the author is naive or disingenuous to try to argue against this.  Twenty years ago, climate science was a backwater with no money and no prestige.  Now governments of the world spend billions, and Presidents know their names.  Just the fact that average people know the names James Hansen and Phil Jones and Michael Mann disproves the authors point.

However, I am more than happy to totally leave this point behind and just forget about it, if I am allowed just one playground rejoinder – you guys started it.  I am wondering why this argument was OK for years when it was skeptics and a few thousands of Exxon’s money but is now totally irrelevant when the alarmists are getting most of the funding, and the money runs up into the billions.  But, as I said, if we want to declare a truce on ad hominem funding arguments, fine by me.

Claim 7: Technological fixes, such as inventing energy sources that don’t produce CO2 or geoengineering the climate, would be more affordable, prudent ways to address climate change than reducing our carbon footprint.

I am not a big fan of geoengineering climate, any more than I am of micromanaging economics.  The same problems apply — where systems are complex and chaotic, the potential for unintended consequences are high.

Here is what he left out

So now its my turn.  I will propose my own seven skeptic’s claims that are much more at the heart of our argument but which you never, ever see addressed in these type articles.  By the way, if you think I am somehow moving the bar, see my climate speech, published before the Scientic American article, which highlights the claims below.  Or see Richard Lindzen’s excellent summary article in the WSJ.

Claim A: Nearly every scientist, skeptic and alarmist alike, agree that the first order warming from CO2 is small.  Catastrophic forecasts that demand immediate government action are based on a second theory that the climate temperature system is dominated by positive feedback.  There is little understanding of these feedbacks, at least in their net effect, and no basis for assuming feedbacks in a long-term stable system are strongly net positive.   As a note, the claim is that the net feedbacks are not positive, so demonstration of single one-off positive feedbacks, like ice albedo, are not sufficient to disprove this claim.  In particular, the role of the water cycle and cloud formation are very much in dispute.

Claim B: At no point have climate scientists ever reconciled the claims of the dendroclimatologists like Michael Mann that world temperatures were incredibly stable for thousands of years before man burned fossil fuels with the claim that the climate system is driven by very high net positive feedbacks.   There is nothing in the feedback assumptions that applies uniquely to CO2 forcing, so these feedbacks, if they exist today, should have existed in the past and almost certainly have made temperatures highly variable, if not unstable.

Claim C: On its face, the climate model assumptions (including high positive feedbacks) of substantial warming from small changes in CO2 are inconsistent with relatively modest past warming.  Scientists use what is essentially an arbitrary plug variable to handle this, assuming anthropogenic aerosols have historically masked what would be higher past warming levels.  The arbitrariness of the plug is obvious given that most models include a cooling effect of aerosols in direct proportion to their warming effect from CO2, two phenomenon that should not be linked in nature, but are linked if modelers are trying to force their climate models to balance.  Further, since aerosols are short lived and only cover about 10% of the globe’s surface in any volume, nearly heroic levels of cooling effects must be assumed, since it takes 10C of cooling from the 10% area of effect to get 1C cooling in the global averages.

Claim D: The key issue is the effect of CO2 vs. other effects in the complex climate system.  We know CO2 causes some warming in a lab, but how much on the real earth?  The main evidence climate scientists have is that their climate models are unable to replicate the warming from 1975-1998 without the use of man-made CO2 — in other words, they claim their models are unable to replicate the warming with natural factors alone.  But these models are not anywhere near good enough to be relied on for this conclusion, particularly since they admittedly leave out any number of natural factors, such as ocean cycles and longer term cycles like the one that drove the little ice age, and admit to not understanding many others, such as cloud formation.

Claim E: There are multiple alternate explanations for the 1975-1998 warming other than manmade CO2.  All likely contributed (along with CO2) but it there is no evidence to give most of the blame to Co2.  Other factors include ocean cycles (this corresponded to a PDO warm phase), the sun (this corresponded to the most intense period of the sun in the last 100 years), mankind’s land use changes (driving both urban heating effects as well as rural changes with alterations in land use), and a continuing recovery from the Little Ice Age, perhaps the coldest period in the last 5000 years.

Claim F: Climate scientists claim that the .4-.5C warming from 1975-1998 cannot have been caused natural variations.  This has never been reconciled with the fact that the 0.6C warming from 1910 to 1940 was almost certainly due mostly to natural forces.  Also, the claim that natural forcings could not have caused a 0.2C per decade warming in the 80’s and 90’s cannot be reconciled with the the current claimed natural “masking” of anthropogenic warming  that must be on the order of 0.2C per decade.

Claim G: Climate scientists are embarrassing themselves in the use of the word “climate change.”  First, the only mechanism ever expressed for CO2 to change climate is via warming.  If there is no warming, then CO2 can’t be causing climate change by any mechanism anyone has ever suggested.   So saying that “climate change is accelerating” (just Google it) when warming has stopped is disingenuous, and a false marketing effort to try to keep the alarm ringing.  Second, the attempts by scientists who should know better to identify weather events at the tails of the normal distribution and claim that these are evidence of a shift in the mean of the distribution is ridiculous.  There are no long term US trends in droughts or wet weather, nor in global cyclonic activity, nor in US tornadoes.  But every drought, hurricane, flood, or tornado is cited as evidence of accelerating climate change (see my ppt slide deck for the data).  This is absurd.