claim: Big rooftop solar's plan forces Nevada families who don't have solar panels to pay higher power bills to subsidize rooftop solar.
evidence: Concentrations of CO 2 in the atmosphere were as high as 4,000 parts per million (ppm, on a molar basis) during the Cambrian period about 500 million years ago to as low as 180 ppm during the Quaternary glaciation of the last two million years.