Continuing my critique of http://xtronics.com/reference/globalwarming.htm, picking up with the section titled:
"To infer a connection between man emissions of CO2 and warming is not an easy jump for the scientifically minded".
Here the author attempts to outline 6 things that must be done to "infer a connection" between human activities and global warming...
1) "prove the CO2 increases are caused by humans". This is actually relatively straightforward and has been part of the science rarely challenged by any serious scientific study. Basically, we can measure how much CO2 is in the atmosphere and, based on its radioactive signatures, what the source is. A good explanation of this is at RealClimate and another at the US Global Change Reseach Office. So the science says the CO2 levels are increasing and the vast majority of that increase is caused by human activities. And the idea that CO2 comes mostly from volcanoes is just wrong. It is not supported by any empirical data and shows that the author of this article has spent no time studying the science. For a good summary of volcanic contributions to the carbon cycle, see this 2005 British Geological Survey study wherein it states "The contribution to the present day atmospheric CO2 loading from volcanic emissions is, however, relatively insignificant, and it has been estimated that subaerial volcanism releases around 300 Mt/yr CO2, equivalent to just 1% of the anthropogenic emissions" (emphasis mine).
2) "show the elevation of CO2 to be 'historically real'". Again, this is part of the science rarely challenged by serious scientific study and further proof the author of this page doesn't know what he's talking about. Here's a graph of CO2 over the last 400,000 years - it has historically fluctuated between 180 and 300 ppm and is now currently at 380 ppm and rising rapidly. I would assume that 400,000 years is "historically real".
3) "need a "theory" that can predict the past". I already answered this one in my last post - the AGW models do accurately predict past and present trends)
4) this item is basically incoherent. It states "Fourth, as this is an open system where we can't build several earths and vary only one constant, any conclusion at best is still just a theory - an educated guess - it is not scientific fact. Science is more than looking scientific; just because things are measured to several decimal points means naught when there is no control or false logic." Huh??? AGW is a theory, not a "fact". As with any theory, it is designed to explain observations (which are representations of the "facts"), not to be a fact itself. This shows again that the author of this page is exceedingly naive and does not understand science or the scientific method at all. And by the way, the earth's climate is not an "open system" (the energy inputs and outputs are relatively easy to identify and measure), it is just that it is a large and complex system with a high degree of variability. This makes accurate predictions difficult, but not impossible.
5) the fifth point is a fairly incoherent collection of ideas, but the primary idea seems to be that current warming is all caused by the sun (which has been disproved over and over, but don't let me get ahead of myself). His first idea is "to look at the past temperatures honestly, one would have to show no past periods of higher temperature". This is actually not true - "one" would only need to show that there have not been higher temperatures in the civilized human experience - which is exactly what proxy data shows. The real concern over AGW is not whether the earth has ever been this hot (it was, after all, once a ball of molten lava) but whether human civilization has ever had to deal with this rapid and this high an increase in temperatures. The answer is no, we have not - here's an average temperature reconstruction for the last 1000 years and here is the last 2000 years and the last 10,000 years. Current temperatures are higher than at any time during human civilization, which is as far back as "one" needs to go.
Still in section 5, his next idea is "we only have accurate records of solar output from the recent past and we are ignorant of the magnitude of long term historic variations that are possible." Huh? We have instrumental temperature records (not "solar output") for the last 120-150 years that show unmistakable warming and we are not "ignorant" of the "historic variation" at all as indicated by the temperature reconstructions I reference above.
He goes on to state that "glaciers world wide have been shrinking for the last 300 years", which they haven't, and that "things other than CO2 change our climate", which is true and has never been disputed by the AGW theory (other factors including solar radiation, geothermal venting, aerosols, etc. are all included in the AGW theory, they just don't account for the observed warming).
Next he references "Space Weather" which in turn references the 1991 Friis-Christensen-Lassen "correlation" between solar activity and global temperature. This is not only an old study from 1991, but it has been thoroughly refuted - see this 2003 study by Laut et. al. wherein they showed that Christensen et. al. used two different statistical methods to "smooth" the data - one for the data from 1860-1950 and then a completely different method for the data from 1950 to 1991. In 1999, Lassen revisited the data with a consistent "smoothing" algorithm and concluded "that since around 1990 the type of Solar forcing that is described by the solar cycle length model no longer dominates the long-term variation of the Northern hemisphere land air temperature" (see fugure 3, page 15 here). Not to mention that the entire scope of the 1991 study was northern hemisphere temperatures, not global temperatures. So this site is quoting narrow, out-of-date, refuted evidence while saying that the proponents of AGW don't know what they're talking about. This is classic cherry-picking and very very common among global warming skeptics. He then goes on to reference this article as "proof" that the Sun is causing all the current warming when this is an article about hydrometeorological processes (i.e. rainfall) not global temperatures.
Then, still in section 5, there is the wonderful graph of "Northern Hemispheric Land Temperature and Solar Cycle" which does not link to its source (a big red flag when you're looking for real science and not just political clap-trap) except that the graphic itself does say it's source is "S. Baliunas and W. Soon / Astrophysical Journal" (two well-known Global Warming skeptics). A quick search of the Astrophysical Journal website finds only one paper by Sallie Baliunas and Willie Soon that references solar radiation and temperature (there are many others on different topics), but it was published in 1996 (therefore also way outdated) and doesn't have a graph anything like the one on the Transtronics page. And the reason Baliunas and Soon are "well known" skeptics is because they published a paper in 2003 that was used by Inhofe and the Republicans to help defeat ratification of the Kyoto protocols and was later shown to be scientifically flawed. This is an excellent example of the skeptics using the precise tactics that they claim AGW proponents use - using shoddy science as the means to political ends. The Chronicle of Higher Education wrote about this when the story broke. They outline all the issues with the Baliunas/Soon articles (was not properly reviewed before publication, was specifically reviewed by someone friendly to its conclusions, was at least partially financed by special interests for political reasons, etc. etc.). None of this stops the skeptics from continuing to quote the outdated, debunked findings from this and many other older, flawed studies.
6) lastly, the author makes another barely coherent statement that "one really has to subtract the effects of variations of solar output, and changes in land use (irrigation) from any temperature trends. There is no way to do this with any meaningful accuracy." Again, solar variations are well accounted for in AGW theory and "land use" is really more about deforestation (something that is easily measured with a great degree of "meaningful accuracy"), not "irrigation". If this were a legal case against AGW, the judge would be throwing it out, possibly with a contempt charge :)
I'm not even half way through the web page - there is much more to come...