In other posts, I have discussed the800-year lag between temperature and CO2in the ice core histories. For those not aware of the issue, ice core data, like that shown by Al Gore in An Inconvinient Truth, initially showed a very strong and compelling correlation between CO2 and temperature. Not only did CO2 look like a driver of climate, it looked like the driver.But Gore is very careful how he presents this chart in his movie(one of his Really Big Charts). The reason is that by the time of the movie, better instrumentation and lab procedure had shown that temperature increases in the ice core data actually preceeded CO2 increases by 800 or more years. CO2 was being increased by heating of the oceans and outgassing of CO2 from them, not the other way around.
Pretty compelling. Every 75,000 years or so there is a CO2 spike, followed by a temperature spike. But the SPPI folks found something interesting by going back to the original source: Laurie David has reversed the legend. They have called the red line CO2, when in fact it is temperature, and vice versa, reversing the causality back the way she apparently wants it.
SPPI goes back to David's source just to make sure, and yes, the original study behind the chart confirms that temeprature rises before CO2.
On page 103 of their book, David and Gordon cite the work of Siegenthaler et al. (2005), for their written and graphical contention that temperature lags CO2. However, Siegenthaler et al. clearly state the opposite:
“The lags of CO2 with respect to the Antarctic temperature over glacial terminations V to VII are 800, 1600, and 2800 years, respectively, which are consistent with earlier observations during the last four glacial cycles.”
(Siegenthaler et al., 2005, Science, vol. 310, 1313-1317)
The ice-core data is frequently cited as principal evidence to argue that CO2 is the earth’s main climate driver. It is, in a way, the jewel in the crown of the theory of man made global warming. But the ice-core data does not show that CO2 drives climate. It shows, very clearly, that variations in temperature precede rises in atmospheric CO2 – not the other way round. The two phenomena are divided by a time lag of several hundred years.
There is no evidence that CO2 has ever ‘driven’ the climate in the past, nor is there any compelling evidence that it is doing so now.
According to global warming theory, if an enhanced greenhouse effect (from increased levels of CO2 or indeed any other greenhouse gas) is responsible for warming the earth, then the rate of temperature rise should be greatest in that part of the earth’s atmosphere known as the troposphere, specifically in the tropics. And yet the observations, from weather balloons and satellites have consistently shown that not to be the case. I urge readers to look at the Christy et al papers below. The latest one was recently published in the Journal of Geophysical Research (2007). This may seem like a rather technical issue, but it strikes at the very heart of the theory of man made global warming.
The Myth of Dangerous Human-Caused Climate Change Read More
Tropospheric temperature change since 1979 from tropical radiosonde and satellite measurements” – John R. Chirsty, William B.Norris, Roy W. Spencer, Justin J. Hnilo Journal of Geophysical Research, VOL. 112, D06102 Read More
Satellite and VIZ-Radiosonde Intercomparisons for Diagnosis of Nonclimatic Influences – John R. Christy and William B. Norris Read More
Journal of Geophysical Research, Vol.109 109, D14108, doi:10.1029/2003JD004414, 2005 - an assessment of three alternatives to linear trends for characterizing global atmospheric temperature changes Read More
Journal of Geophysical Research Vol. 109, D14108, doi:10.1029/2003JD004414, 2004 - an assessment of three alternatives to linear trends for characterizing global atmospheric temperature changes Read More