In the year 2000 15 billion gallons of soda pop were sold in the USA. A 16 oz bottle of soda holds about 2.2 grams of CO2. So a gallon would hold 8X as much or 17.6 grams. So 15 billion gallons would hold 264 billion grams. Or 264 million kilograms. Or 264,000 metric tons. Or .264 million metric tons. In 2007 the USA released 5,984 million metric tons. So soft drinks represent .0044% of the USA's total CO2 output. Roughly. I'll bet even if you add in beer and champaign it doesn't amount to much. And if the sun is the real driver of climate and the heating and cooling of the oceans determines the amount of CO2 in the air, then all the CO2 the USA puts out still doesn't amount to much. At least as far as climate change is concerned.