Hendrik Tennekes

Atmospheric scientist Dr. Hendrik Tennekes, a scientific pioneer in the development of numerical weather prediction and former director of research at The Netherlands' Royal National Meteorological Institute, and an internationally recognized expert in atmospheric boundary layer processes

List cites a few blog posts

Arguments Condensed:

• Models might be wrong
• Climate modellers are incompetant
• Scientific conspiracy
• Accepts human co2 induced warming

Quotes

• "I am of the opinion that most scientists engaged in the design, development, and tuning of climate models are in fact software engineers. They are unlicensed, hence unqualified to sell their products to society."
• "I agree with IPCC that there is a likely link between fossil fuel consumption and increased temperatures"

Chris Schoneveld

Dutch Geologist Dr. Chris Schoneveld, a retired exploration geophysicist, has become an outspoken skeptic regarding the human influence on climate over the past four years.

List cites a comment to a media article and there's also a blog comment
He has a profile page here: http://www.atheistnexus.org/profile/ChrisSchoneveld
And a long message/letter:

Arguments Condensed

• Climate's changed before
• It's uncertain

Quotes:

• "There has never been a UN-organized conference on climate change where skeptics were invited for the sake of balance to present their case"
• "As long as the causes of the many climate changes throughout the Earth's history are not well understood, one cannot unequivocally separate natural causes from possibly manmade ones."
• "Who are the geologists that the IPCC is relying on? Is the IPCC at all concerned about the frequency and recurrence of ice ages? Who are the astronomers that advise the IPCC on other cause of possible climate change (sun spots or earth’s elliptical orbit, tilt and wobble of its axis) so as to ascertain that we are not just experiencing a normal trend related to interglacial warming or variation in solar radiation?"
  
  

Classifying Arguments

To move towards classifying skeptics I thought to first try and categorize their arguments at a very high level, so looking at maybe half a dozen different groups that all arguments can be put into. A good example of grouping arguments can be seen in the structured heirarchy of Creationist Claims. Those are field based categories though, I want to group the fundamental argument types.

So far I have come up with a preliminary 5 groups:

• Data Based: "I am skeptical because of this simple fact...."
• Ignorance based Arguments: "I am skeptical because we don't know enough"
• Theory Based: "I am skeptical because I know of an equally good/better theory to explain it."
• Political: "I am skeptical because Al Gore flies in a private jet"
• Conspiracy: "I am skeptical because they are in it for the taxes and grants"

I'll update this in future as I think it can be improved, but here is some more detail and explaintions about these categories:

Data Based

• It hasn't warmed since 1998 (literally true, but in context of climate, wrong)
• Human co2 is a tiny % of co2 emissions (literally true but irrelevant)
• Water vapor is the most powerful greenhouse gas (literally true but irrelevant)
• Volcanoes emit more co2 than man (false)

These are simple claims about basic data. It's pretty simple to check whether these are true or not. Usually such claims are at least literally true, but misleading in some way - ie strawmen, or omitting an important fact.

Because these claims are so easy to verify, it is a real red flag when someone who should know better uses them as an argument.

Ignorance based Arguments

• Climate is all chaotic and we don't understand it at all
• Uncertainty mentioned in IPCC reports, some paper, temperature records
• Models are unreliable
• The concept of global temperature is meaningless

Usually made by people who stick to Political Arguments. The result of such arguments is that the arguer doesn't have to get into the science. They might argue that any theory of climate is as good as any other.

Theory based arguments

• It's the Sun
• Imminent global cooling
• The greenhouse effect is a myth
• co2 was higher in the 40s [2]
• (insert personal climate theory)

These arguments go beyond simple claims based on data. These are alternative theories contradicting the mainstream. They have to explain why they don't accept the mainstream theory. This often occurs in three ways:

• This has simply overturned the mainstream theory.
• An Ignorance based Argument: They claim that their theory is no less likely than the mainstream one because so little is known, etc.
• A Conspiracy Argument: For example Ernst Beck who coined the "co2 was higher in the 40s" theory uses a Conspiracy Argument to explain the existance and acceptance of the mainstream theory.

Note that the first and third cases are making positive assertions about how the climate works (or some aspect of it) and therefore they can no longer make Ignorance based Arguments in these areas. For example if they are going to claim "recent warming on earth is caused by the sun" as a fact they then can't turn around later and claim "The concept of global temperature is meaningless" without contradicting themselves.

Political Arguments

• Al Gore's house has a runway of Private Jets
• I am skeptical because environmentalists don't live in mud huts

These arguments have no bearing on the science. I have distain for these arguments. I generally ignore them, but I include them as a group here because often these arguments are made by the same skeptics. As noted above these arguments are often made in conjunction with Ignorance based Arguments.

Conspiracy based arguments

The Journal of Inactivism has an interesting genealogy of climate conspiracy theories which lists the various conspiracies used by skeptics to explain why manmade global warming is such a prominent theory. Highlights include:

• In the 80s we get "Mainstream scientists are soviet stooges", it's a "soviet plot" [1]
• A "doctrine to replace marxism" [1]
• Scientists "artifically sustain debate" (ie "commit fraud") for funding and grants [1]
• Politicians use it to increase taxes [1]
• I've heard Margret Thatcher get blamed for it somewhere

I will probably revisit this list at some point and update it. Some arguments can be seperated out better and I might be missing some categories. Ideas/corrections are welcome.

References
[1] F. Bi. 2008. Towards a genealogy of climate conspiracy theories. Intl. J. Inact., 1:37–42

[2]E. Beck. 2007. 180 years of atmospheric CO2 gas analysis by chemical methods., Energy & Environment, Volume 18 No. 2

Philip Stott

UK Professor Emeritus of Biogeography Philip Stott of the University of London
List cites this EPW blog post

He also has a blog

Arguments Condensed

• climate's changed before
• We know very little about climate
• It hasn't warmed since 1998 (although specifically he says "since at least 2001")

Quote

• "But, finally, we must return to basic science. Climate is the most complex, coupled, non-linear, semi-chaotic system known. The claim by UK MPs that they can manage climate predictably is the ultimate folie de grandeur. In such a system, both doing something (i.e., emitting gases) and not doing something (i.e., not emitting gases) at the margins are equally unpredictable as to outcomes." [ref]
• "Interestingly, the world average surface temperature has now exhibited no ‘global warming’ since at least 2001" [ref]

Notes:

• He argues mainly from politics, only occasionally wading into trying to justify his claims scientifically

Ernst-Georg Beck

German scientist Ernst-Georg Beck, a biologist, authored a February 2007 paper entitled 180 Years of Atmospheric C02 Analysis by Chemical Methods that found
levels of atmospheric CO2 levels were not measured correctly

A paper published to the Journal "Energy and Environment":
http://www.biokurs.de/treibhaus/180CO2_supp.htm

There are also other statements made on the same website, eg:
http://www.biokurs.de/treibhaus/CO2-Dateien/CO2-no-climate-driver.pdf [ref1]
http://www.biokurs.de/treibhaus/CO2-Dateien/7-kern-PIKe.pdf [ref2]

Arguments Condensed

• Atmospheric co2 level was higher in the early 20th century
• Ice core co2 histories are wrong
• Scientific conspiracy
• Human co2 is a tiny % of co2 emissions (2)
• Ocean acidification is of no concern (3)

Notes:

• There's a gold mine of claims on that site, just about every claim under the sun can be found.
• In the PDF above he compares co2 concentrations with temperature of antarctica over 200 years and concludes "there is no connection"
• (2) [ref2] "A reduction of anthropogenic greenhouse gas emissions by 1% means 26GT/year instead of about 29 GT CO2/year (= 3% of the whole natural CO2 emissions). The 26,7% are still negligible compared to the natural emissions of oceans and biomass."
• (3) [ref2] "A pH-range of sea water of 8,2-7,7 is a normal range and was still measured during the warm period since 1920 and 1930 [4]. A pH higher than 7 is still alkaline."

"analysis" of list so far

About 24 entries have been added. It was decided that 5 of them shouldn't be on the list as they didn't show any convincing skepticism of manmade global warming.

That leaves 19. There are a number of issues with doing any meaningful analysis on this, including:

1. There are only 19
2. The 19 are not a random sample from the list.
3. There are probably gaps where I didn't see an argument used
4. They are represented unequally. Some have whole websites full of arguments, some only a single short letter of arguments.

This is the reason for quotes around "analysis" in the title. What follows is simply an interest/trivia look at an aspect of the entries so far.

The top 5 arguments used by the 19 entries and the breakdown are:

It's the sun (6) Bob Breck, John L. Casey, Art Horn, Dr. Cal Evans, Mike Thompson, Richard Mourdock

water vapor is the most powerful greenhouse gas (6) Bob Breck, Dr. Martin Hertzberg, Dr. Robert H. Essenhigh, Frank Britton, Art Horn, Dr. Cal Evans

CO2 concentration is small (5) Bob Breck, Dr. Martin Hertzberg, Hans Schreuder, Frank Britton, Dr. Cal Evans

It hasn't warmed since 1998 (5) Bob Breck, Dr. Wilson Flood, Allan M.R. MacRae, Bill Steffen, Joseph Conklin

human co2 is a tiny % of co2 emissions (4) Dr. Robert H. Essenhigh, Frank Britton, Art Horn, Mike Thompson

As #3 and #4 points out, the reason many of the same names are present is probably due to unequal representation.

A relevant hypothesis I have held for a long time, not based on the above, is that whatever makes a person susceptible to believing one of the worst arguments (I consider the above to be some of the worst), they will be susceptible to all of them.

ie if a person is not skeptical of the "human co2 is a tiny % of co2 emissions" and readily believes it, then they will very likely also be taken in by the "water vapor is the most powerful greenhouse gas" argument. At least I see little reason why a person would believe one and not the other.

So I suspect to see a pattern like the above where a person using one argument will tend to also be using the other.

Skepticalscience directly covers 4 of the 5 above arguments, with "CO2 concentration is small" covered in related topics. It is interesting that the worst arguments are perhaps the most popular, but perhaps this is explained by the simplicity of the arguments and the relatively few people who look into them in any detail.

So a classification system for skeptics will probably contain a large group consisting of people that believe these type of arguments. There are many other skeptics who would distance themselves from such arguments and so would have to placed in different groups.

Bruce Schwoegler

Atmospheric scientist Bruce Schwoegler, former U.S. Navy meteorologist and Boston broadcast meteorologist, rejected man-made climate fears.

List cites a letter to the list creators.

Arguments condensed

• "significant global warming is a concern"
• "there is a likely relationship between human induced impacts and climate change"
• It's all too complicated!

Quotes:

"But has anyone truly ascertained the scope, depth and outcome in our planetary system which is rife with natural checks and balances? Quantifying them and resultant interactions remains mostly a game of my theory versus yours"

Notes

I added this one for variation. It is a position of 'we don't know enough to conclude anything'. This position is in contradiction of the position of skeptics who claim to know that warming is not due to greenhouse effect enhancement (such as the EPW he is writing to for example...). He also mentions significant global warming as a concern, at odds with skeptics who have the position that warming is beneficial (although this depends on what "significant" is).

trivia: I hit my first duplicate just now. I almost started doing John L. Casey again, fortunately I got deja-vu just in time.