Modding stuff down doesn't actually change the facts, you know.
CO2 levels:
http://www.geocraft.com/WVFossils/Carboniferous_climate.html
The sources are all linked from this site.
Note that the CO2 level in the Cambrian was around 7,000 ppm, or about 17 times the level that this article is having hysterics about. Note that even during the Jurassic (when there were plenty of large land animals and a flourishing ecosystem) the level was about 3,000 ppm (7 times higher than the articles "threshold"). I repeat: the Earth was fine.
2. Extinction. The Wikipedia article I linked has a chart showing the proportion of species that have gone extinct during previous mass extinction. Note that the currently touted "mass extinction" is just a tiny blip.