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RESPONSE TO DISCUSSION BY BRYAN LOVELL
I appreciate receiving Lovell's discussion to my earlier article (Gerhard, 2004). It permits readers to learn more about dissent over climate change drivers and the literature and data that drive that dissent.
Lovell (2006) argues that human-contributed greenhouse gases are the major driver of climate change. Although positive correlation cannot prove a concept, negative correlation can disprove a hypothesis. Little correlation exists between the smooth and steady rise in carbon dioxide concentration in the Earth's atmosphere, the almost imperceptible rise in temperature measured in the lower stratosphere by balloons and satellites, and the multidirectional and multidecadal rise and fall of Earth's temperature over the last 150 yr (Khilyuk and Chilingar, 2004). Interestingly, the NASA graph of United States temperature documents that the United States has cooled 0.7°C since 1998 (National Aeronautics and Space Administration, 2005).
In contrast, correlation exists between solar and orbital variations and the Earth's climate over the last 150 yr and before (Reid, 1991; Hoyt and Schatten,1997; Bond et al., 2001). We are about 1100 yr beyond the medieval warm event (Lamb, 1995) and likely near the cusp of the modern warm event. Khilyuk and Chilingar (2004) have summarized many of the arguments for nonanthropogenic climate drivers. New studies (Scafetta and West, 2005; Usoskin et al., 2005) demonstrate the function that orbital and solar variations may have in climate change.
This is not to say that there is no impact of growing carbon dioxide in the atmosphere, regardless of its source. But the data and the correlations negate carbon dioxide as the single major driver of climate change. It is the responsibility of computer modelers to revamp their algorithms to acknowledge solar and orbital correlation and reflect recorded climate history.
Lovell (2006) believes that human use of fossil fuels is responsible for major …