Thursday, April 24th 2008, 6:27 PM EDT
I've been a Fellow of the Royal Meteorological Society since 1968. Admittedly that was before a science qualification was required but I've been a weather and climate geek for over 50 years.
The alleged link between cosmic ray flux and cloudiness remains to be proved or disproved.
The link between solar cycle length and decadal global temperature changes is obvious throughout all the weather records. It's not strictly a sunspot issue, it just happens that the longer the solar cycle is the less intense is the sunspot activity and presumably the overall heat output ( not necessarily the same as what we artificially term Total Solar Irradiance) during the cycle.
Short fast cycles with many sunspots result in warming. Long slow cycles with fewer sunspots result in cooling.
The mechanism which explains the clear and obvious link has not been ascertained adequately but it sure ain't anything to do with CO2. It is likely that the El Nino/ La Nina cycle is implicated with a dominance of El Nino resulting in global warming and a dominance of La Nina resulting in global cooling.
The scale of the solar induced natural variability that has been observed over more than 500 years totally swamps any warming effect from human CO2. It is even possible that human cooling influences such as particle emssions and albedo changes from crop growing could offset any human induced warming already. There are no calculations quantifying both warming and cooling human influences so we have no idea what our net influence might be.
It is clear that the late 20th Century warming spell matched the duration of the two shortest, fastest solar cycles in the historical record ( 21 and 22) At the same time thare was a matching sequence of strong El Nino events. These points should not be lightly dismissed. The cooling fears of the 60's and early 70's coincided with weak cycle 20 and the cessation of warming occurred during cycle 23 which has been weaker than the two cycles before it.
On balance the evidence shows that solar is more likely the cause than CO2 but the issue can soon be resolved by observing the global temperature changes that occur as a result of the extended cycle 23 and the probable weak cycle 24.
If we now get a period of natural cooling it might well last several decades.There has been a gradual background and wholly natural warming trend since the end of the Little Ice Age. Of course it is all a matter of trends over time periods. You can 'prove' any trend you require by choosing the right time scale. What matters is the scale of human influences either towards cooling or towards warming as against the underlying trend behind natural variability. It really is an unknown quantity. Even the scale and trend behind natural variability is subject to an unknown number of overlapping cycles from multiple causes many of which are unknown, unquantified or both.
Making policy decisions on the basis of current knowledge (and in the light of recent observations) would be wholly irresponsible. Using food for biofuel production should be a crime and yet that is the single most influential result of global warming alarmism so far. Just the start of the potentially murderous cycle of bad policy decisions that are likely to be based on a false premise.
I was open minded as to the cause of global temperature changes when I started my work time ago. At first all I was pointing out was my observation of a change in global weather patterns around 2000 from a warming mode back to those of the cooling mode of the 60's and 70's. Observations since then have shown me to have been right. I was also doubtful about the standards of accuracy in official recording sites due to urban development. That doubt was prompted by my own observations of how much a nearby building affected my own readings and has been vindicated by recent surveys of U S recording sites showing a pitiful attention to site standards.
After a great deal of reading and research since then I have come more and more to the view that solar is more important than CO2 on all the evidence available and if that causes me to be out of line with the IPCC and any number of scientific experts then, tough.
This is one of many replies in our comments section at CO2Sceptics: -
"I too am a CO2 sceptic because the ball is in their court and they will not hit it back. Where is the CO2 research? The Danish National Space Centre has been researching solar for 25 years."
"What has the AGW side done"?