Revisiting the scare about carbon pollution–yes, ninny, you exhale CO2 at 40,000 PPM

In the ambient air CO2 (carbon dioxide, a non toxic, invisible odorless gas) is around 400 PPM by volume, which is 0.04% by volume. Exhaled air from humans and mammals is about 4% CO2, 40,000 PPM by volume. By comparison … Continue reading →