So just what is this atmospheric pollutant we call carbon dioxide? Is it a deadly greenhouse gas much of which we should get rid of?
Without it we'd all be dead. Plant life would vanish, and with it all of humanity.
Simply put, plants inhale CO2, convert it into sugars that enable them to grow and thrive, and exhale oxygen — the stuff that keeps us alive.
According to Dr. Tim Ball, a renowned environmental consultant and retired professor of climatology at the University of Winnipeg, plants require CO2 to exist as we require oxygen to exist.
As the amount of CO2 in the atmosphere increases the plants grow more vigorously. Current levels of atmospheric CO2 is 385 ppm (parts per million) but research shows that plants grow most vigorously at 1,000 to 1,200 ppm, which is why commercial greenhouse pump that much into their atmospheres.
In fact, no one is claiming that carbon dioxide, in and of itself, is a pollutant. Rather, scientists argue that excessive levels of CO2 in the atmosphere can have a polluting effect, and that global industrialization has increased the amount of CO2 in the atmosphere -- an argument Brennan does not address.
Brennan also repeats the denier claim that "temperature levels have been falling for the past 10 years." In fact, the past decade includes many of the warmest years on record, and scientists who aren't on the take from oil and gas companies believe that the Earth remains in a long-term warming trend.