Too much of a good thing

http://www.msnbc.msn.com/id/12857723/

The oil industry is running ads with the slogan “Carbon dioxide: they call it pollution; we call it life.” Unfortunately, our citizens are so poorly educated in science, and so well-trained to not think, that many people will probably be taken in by these ads. Presumbably, they were market-tested and found to be effective before being released.

Of course, carbon dioxide (CO2) is essential for life; w/o it our world would be an ice cube. However, a substance or activity in small or moderate quantities can be harmful or fatal in larger quantities. Eg., fat-soluble vitamins A and D. In fact, polar bear liver contains so much vitamin A, it is toxic.
http://www.polarbearsinternational.org/polar-bears-in-depth/physiology/
Small amounts of arsenic have been shown to be necessary for the health of at least some animals. That doesn't keep it from being a poison and carcinogen at more than trace amounts.
http://www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/ars_0026.shtml
Of course, if our citizens had a minimum of scienctific understanding, they would see the silliness of these ads. CO2 is a waste product for animals. Too high a concentration kills us by crowding out oxygen. We aren't likely to be in danger from that. The big problem is that we are increasing the amounts of greenhouse gases too quickly for much of nature, of which we are a part, and on which we are dependent, to adapt.

http://portland.indymedia.org/en/2004/09/297818.shtml
http://www.chriscodes.com/store/detail/books/related_result/Book/1572304510/
I have been feeling for awhile that the leaders of Mobile-Exxon, who fund many or most campaigns to resist dealing with the threat of increasing greenhouse gases, are sociopaths (the modern term for psycopaths), and now am really convinced.