A paper just published in the prestigious journal Science (June 21, 2013) raises yet more fundamental questions-or at least it should-about the arbitrary designation of atmospheric CO2 as a "pollutant," in conjunction with anthropogenic climate "warming" hysteria.

Investigators employed standard, robust multi-proxy techniques based upon examining sediments recovered from Lake El'gygytgyn in  northeast Arctic Russia (100 km north of the Arctic circle in Chukotka, Russia) to determine local temperatures between 3.6 to 3.4 million years ago. Their findings revealed that during this middle Pliocene era period,

...summer temperatures were ~8 degrees C warmer than today, when the partial pressure [i.e., atmospheric concentration of] CO2 was ~ 400 parts per million [ppm]

The most recent data available from the US National Oceanic and Atmospheric Administration (May, 2013) at Mauna Loa, Hawaii, and "globally", demonstrates current atmospheric concentrations of CO2 are 399.77, and 396.72 ppm, respectively. Thus  at essentially the same CO2 concentrations as those determined from ~3.5 million years earlier, and in the absence of "anthropogenic" CO2 production (i.e., by our bipedal Middle Pliocene ancestors!) any where comparable to what it is now, Arctic temperatures then were ~8 degrees C warmer than at present.