This easy 20-minute sunny-day experiment compares the change in temperatures of  two one-liter bottles left in bright sunlight, where only one is filled with mostly CO2 obtained using half the contents of a can of seltzer or soda (heavier CO2 pushes out N2 and O2). The other liter bottle gets the other half of the soda can contents, first made flat (removing CO2) to provide a convincing control. An IR thermometer might be used for this lab.

We thank Mary Lou West, mathematics professor emeritus from Montclair State U. and astronomer.