New studies are continually challenging the simplistic view of the Intergovernmental Panel on Climate Change (IPCC) that increases in the partial pressure of the air's CO2 content (pCO2) have a major, if not phenomenal, impact on earth's climate. The most recent variant of one of these challenges is presented by Shaviv and Veizer (2003), who suggest that from two-thirds to three-fourths of the variance in earth's temperature (T) over the past 500 million years may be attributable to cosmic ray flux (CRF) variations due to solar system passages through the spiral arms of the Milky Way galaxy. After presenting...