CFCs or CO2?

This writer makes an excellent case that CO2 is not impacting the climate at all for a number of excellent reasons.  He also makes the case for CFCs as a reasonable alternative in view of the information on hand.

In other words, if you like two graphs that have correlation, then CFCs give it to you.

Unfortunately, it is a one time exercise in coincidence that may not survive repetition.  In fact, I am pretty sure that the CFC part will never be repeated.

So we have an interesting coincidence which is a lot more than the CO2 crowd actually had.  There they arguably had ten years of possible correlation out of a century of signal noise.

It is an interesting paper and an interesting conclusion.  I simply see better alternatives and the geological record clearly tells us that we are still in the signal noise channel.

What is the Major Culprit for Global Warming: CFCs or CO2?

Qing-Bin Lu, Ph.D.,
Department of Physics and Astronomy and Departments of Biology and Chemistry, University of Waterloo, Waterloo, Ontario, CANADA


A recent observation strikingly showed that global warming from 1950 to 2000 was most likely caused by the significant increase of chlorofluorocarbons (CFCs) in the Earth atmosphere (Lu, 2010). Here, three key questions are addressed: (1) How could CO2 play a negligible role in recent global warming in view of its extremely high concentrations of ≥300 ppm? (2) Is there other evidence from satellite or ground measurements for the saturation in warming effect of CO2 and other non-CFC gases? And (3) could the greenhouse effect of CFCs alone account for the rise of 0.5~0.6 K in global temperature since 1950? First, the essential feature of the Earth blackbody radiation is elucidated.

Then re-analyses of observed data about global temperature change with variations of halocarbons and CO2, the atmospheric transmittance of the infrared radiation and the 1970-1997 change in outgoing longwave radiation spectra of the Earth are presented. It follows by new theoretical calculations of the greenhouse effect of halocarbons. The results strength the conclusion that humans were responsible for global warming in late 20th century, but CFCs, rather than CO2, were the major culprit; a long-term global cooling starting around 2002 is expected to continue for next five to seven decades.

5. Concluding remarks
In comparison with previous calculations on the greenhouse effect of CFCs, the present calculations give rise to a larger greenhouse effect. This is due to two factors: the former calculations significantly underestimated the amplification factor of water vapor feedbacks by using a much smaller β value of 0.15 (Ramanathan, 1975) and also overestimated the greenhouse effect of CO2 by assuming a logarithmical increase in radiative forcing of CO2

It should be noted that the application of the CO with increasing concentration (Ramanathan et al., 1985, 1998; IPCC, 2001, 2007). These should be revised with the present observations.

2-palaeoclimate relation to the recent anthropogenic warming is questionable. Some studies reviewed in the IPCC Reports (2001, 2007) showed that CO2 co-varied with Antarctic temperature over glacial-interglacial cycles, suggesting a close link between CO2 variation and temperature. Ice core records, however, indicate that the rise in atmospheric COis the effect rather than the cause of surface warming in palaeoclimate.

 For instance, a rapid rise by 5 °C in global average sea surface temperature occurred during transitions from the last Glacial Maximum to the onset of Holocene times; detailed ice core studies by Smith et al. (1999) found that the concentration of atmosphere CO2 increased by about 80 ppm (from ~190 to 270 ppm). But the latter was due to the effect of the rise in global surface temperature on driving more CO2 emission predominantly from the ocean (Smith et al., 1999). If one reversed the sequence and took the CO2 increase as the cause of the 5 °C rise in global surface temperature, then it would be extremely difficult to understand why no global temperature increases were observed for the increases of atmospheric CO2 from 285 to 308 ppm and 310 to 330 ppm in the decades from 1850 to 1930 and 1950 to 1975, respectively. In fact, high-resolution ice core records of temperature proxies and CO2 during deglaciations generally show that Antarctic temperature started to rise about one thousand years before the rise of atmospheric CO2, as well observed by Fischer et al. (1999), Veizer et al. (2000), Caillon et al. (2003) and Stott et al. (2007). And despite strongly decreasing temperatures, high CO2 concentrations can be sustained for thousands of years during glaciations (Fischer et al., 1999). These facts indicate that atmospheric CO2

Finally, accurate and reliable analysis of satellite datasets are often affected by the climate models that investigators use. This is to some extent caused by the complexity of the scientific issue, which might require the use of a certain climate model to guide the data analysis. On the other hand, researchers should also be aware of the fact that used climate models may be incorrect or incomplete. An open opinion about different models may be instrumental in revealing the truth. This study did not aim to make precise calculations of global temperature change with a sophisticated climate model including multiple parameters and factors. But it does show that the warming effect of CO was not the main cause of these climate transitions (Smith et al., 1999; Fischer et al., 1999; Veizer et al., 2000; Caillon et al., 2003; Stott et al., 2007).

and other non-CFC gases had most likely saturated and CFCs and HCFCs could account for global warming observed in the late 20th century. A long-term global cooling starting around 2002 is expected to continue for next five to seven decades.


Global temperature data were from two sources, namely the UK Met Office Hadley Centre: the HadCRUT3 dataset, combined land-surface air temperature and sea-surface temperature anomalies ( and the US NOAA National Climatic Data Center (NCDC): the dataset of annual global (combined land and ocean temperature) anomalies

CO2 data from 1850 to 1958 were from the Law Dome DE08, DE08-2, and DSS ice core measurements (; for the years without recorded data, a linear extrapolation was used to obtain the CO2 data between two closest recorded data points. CO2 data after 1958 were from direct atmospheric measurements at Mauna Loa Observatory, Hawaii
Halocarbon concentrations were from the WMO Report (2007). This work is supported by the Canadian Institutes of Health Research (CIHR) and Natural Science and Engineering Research Council of Canada (NSERC).

No comments:

Post a Comment