800,000 Years March 23, 2012 : 4:19 PM

The level of carbon dioxide n our atmosphere reached 390 parts per million, the highest concentration in nearly 800,000 years:

“Greenhouse gases have risen to their highest level since modern humans evolved, and Australian temperatures are now about a degree warmer than they were a century ago, a major review by the CSIRO and the Bureau of Meteorology has found.”

“The national climate report, to be released today, said Australia's current climate ''cannot be explained by natural variability alone'' and that emissions resulting from human activity were playing an increasingly direct role in shaping temperatures.”

Source: Sydney Morning Herald