Hi delosgatos,

Now that I’ve posted links to some of the many studies on the solar influence on climate, I’ll get to your question:

“Also, I was wondering if you plan on addressing this question which I posted previously: Do you think CO2 levels are unrelated to temperature?"

It is a very good question.

There is the greenhouse hypothesis (Arrhenius) that postulates a causation between average atmospheric CO2 concentrations and “global average temperature” (a rather nebulous concept in itself).

Applying the Stefan-Boltzmann equation and the estimates for radiative forcing for CO2 (Myhre et al.), this tells us that a doubling of CO2 concentrations from the (“pre-industrial”) level of 280 ppmv in 1750 to the projected future level in 2100 of 560 ppmv would result in an increase in “global average temperature” of 0.68C. The numbers are quite easy to crank out without the need of any super-computer.

If you wish, I can crank through the numbers for you.

So, assuming that Arrhenius, Stefan-Boltzmann and Myhre et al. got it right, this tells us that by 2100 we will have seen a 0.68C temperature rise (since 1750) from a 2xCO2 increase.

The calculation also tells us that from 280 ppmv to 379 ppmv (in 2005) we have already seen around 45% of this rise (the relationship is logarithmic) or around 0.3C, leaving us an added 0.4C increase from 2005 until 2100.

So much for theory.

Now, if we go back to the temperature record (let’s use Hadley, which IPCC seems to like), we see that there have been three distinct multi-decadal periods of warming.

These were (with the linear increase recorded over the period):

1858-1879: +0.38C

1910-1944: +0.53C

1976-1998: +0.37C

These warming cycles were interspersed with multi-decadal cycles of slight cooling:

1879-1910: -0.23C

1944-1976: -0.02C

And followed by the current “plateau” since 1998.

The overall underlying trend has been one of warming (somewhere around 1.0C over the entire record).

I've downloaded the Hadley record and plotted it to make this easier to see.

http://farm4.static.flickr.com/3091/2614617358_235d418d98_b.jpg

Now here’s where the answer to your question becomes a bit more difficult.

The late 19th century warming cycle occurred when there was an insignificant change in atmospheric CO2 (around 2 ppmv increase over the period), so CO2 could not have been the cause.

The early 20th century warming (showing 0.53C, i.e. the most warming of the 3 cycles) occurred when there was very little increase in CO2 (around 15 ppmv increase over the 30+ years), so again CO2 could not have been the main cause.

The ensuing mid-century cooling cycle occurred when there was already a significant increase in CO2 (around 25 ppmv increase), yet temperature cooled slightly.

The IPCC “poster period” (for demonstrating the AGW causation) is the late 20th century warming cycle from 1976 to 1998. Essentally all of the AR4 report covers this period, with only casual or cursory mention of the earlier cycles. During this period there is a good correlation (CO2 rose by some 33 ppmv and temperature rose 0.37C).

Unfortunately for the AGW hypothesis, the past 10 years again do not seem to be showing a correlation (flat to slight cooling with record emissions of CO2).

So yes, there is a hypothesis. As far as validation of the hypothesis, there is a good correlation for the most recent warming, a weaker correlation for the earlier warming and no correlation for other warming or cooling cycles.

So I’d say the “jury is still out” on the importance of CO2 as a driver. Causation has not yet been validated by physically observed data.

Hope this answers your question.

Regards,

Max

This is really tedious. Yes, some people has argued that it's changes in solar irradiance that drives climate change, not human activity. Lot of research, bottom line, it's been pretty well shot down.

Manacker posts, taking a random example, a 1999 paper by Lockwood and Stamper.

http://www.wdc.rl.ac.uk/wdcc1/papers/grl.htm

The arguments in the paper were tested, notably by a 2005 paper by Foukal, North & Wrigley.

http://www.sciencemag.org/cgi/content/full/306/5693/68?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=sunspots&searchid=1139607713241_15140&FIRSTINDEX=0&journalcode=sci#ref17

which politely blows most of the argument out of the water.

A more systematic study by the same writers was published in 2006, giving the bottom line:

http://www.ucar.edu/news/releases/2006/brightness.shtml

Similar exercises could be done for the rest of the stack.

The point I'm making is porting unsorted papers and then flatly announcing that they make the case that humans aren't causing climate change is a total crock, a rhetorical trick to intimidate and bamboozle.

My suspicion is that Mnacker hasn't himself read the papers and wouldn't understand them if he did. What I can say for a fact is that he didn't check up to see where they led. I'd rather believe he was mistaken or taken in than lying.

c'mon, don't kid a kidder.

There is the greenhouse hypothesis (Arrhenius) that postulates a causation between average atmospheric CO2 concentrations and “global average temperature” (a rather nebulous concept in itself).

It was a hypothesis at the time Arrhenius, a Nobel prize winner, postulated it more than a century ago. Since then it'sn been confirmed, abundantly. What your laborious stuff about C02 is ignoring is the fact that C02 is only one of a number of gasses. And, again, the people you have to address your thoughts about the science to are the scientists. Go tell the NAS that they don't understand greenhouse forcing. I'm sure they'll be impressed as all hell.

Hi stet,

Been following your exchange with Brute with interest.

Believe Brute has a very good argument that the “science proving a potentially alarming AGW” is anything but settled. All you have to do is look around you, stet, to see that there are still a lot of open arguments from both sides.

The “consensus” argument is flawed. The belief that “scientists know best” is flawed (after all, “climatology” is still in its infancy as a “science” and many of the so-called climate “scientists” are in fact only computer jockeys. And there are many well-known climate scientists that do not agree with the so-called “consensus” view. And, most important of all, science is not a “consensus” game.

It is a game of prevailing paradigms.

The currently prevailing paradigm is supportive of the AGW hypothesis. This is where research funding is going. It is where climate “scientists” get grants.

It has unfortunately become politicized.

Not only are the politicians in the act, but individuals like James E. Hansen who wear the mantle of objective “scientists” have become political activists in support of a “cause” (i.e. “saving the planet”). In so doing, Hansen (who is paid by the US taxpayer to provide unbiased weather and climate information), steps well beyond his area of expertise to talk about extinction of species, spread of vector-borne diseases and other foolishness unless “carbon taxes are implemented”.

The weaknesses of the AGW paradigm are:

· It is based on agenda-driven science

· It is based on computer model projections that suffer from the GIGO problem

· It has not been validated by physically observed data

· It relies upon measurements that are, themselves, so “massaged” that they are non-transparent and subject to manipulation

· It relies on an ineffectual and in-bred “peer review” process

So I’ll have to agree with Brute and disagree with you, stet.

The “science” is NOT “settled” on AGW. Not by a long shot.

Regards,

Max