Another nail in our coffin.
Scripps Institution of Oceanography / University of California, San Diego
For the first time in human history, concentrations of the greenhouse gas carbon dioxide (CO2) could rise above 400 parts per million (ppm) for sustained lengths of time throughout much of the Northern Hemisphere as soon as May 2013.
To provide a resource for understanding the implications of rising CO2 levels, Scripps Institution of Oceanography at UC San Diego is providing daily updates of the "Keeling Curve," the record of atmospheric CO2 measured at Hawaii's Mauna Loa.
"I wish it weren't true, but it looks like the world is going to blow through the 400-ppm level without losing a beat," said Scripps geochemist Ralph Keeling, who has taken over the Keeling Curve measurement from his late father. "At this pace we'll hit 450 ppm within a few decades." [emphasis mine]
I'm wondering what the health effects might be of breathing a different atmospheric composition than the one we've evolved to breathe. Forgetting about other species for the moment, might not breathing more CO2, and less of other gases, create health concerns?
This issue was discussed in a comment by Beth KZ . I think the ratio of oxygen to CO2 matters.
Oxygen levels are generally 21% of the earth’s atmosphere globally, although this number drops to 19% in many areas, and as low as 12% over major industrialized cities. (Professor Ervin Laszlo)
As CO2 rises in major cities, heart and respiratory patients will suffer. Of course particulates matter too.