A New Number, A New Peak

On 5th December, 2012, the Mauna Loa Observatory: Scripps Institutionof Oceanography gave the average value of concentration of atmospheric carbon dioxide in November. Two months ago, before I wrote the first post, the mean atmospheric CO₂ concentration in September was 391.07ppm.The concentration of carbon dioxide in the atmosphere in November 2012 hit a new peak - 392.92ppm. 

A paper by James Hansen from the NASA Goddard Institute for Space Studies stated that “350 parts per million” is the safe upper limit for the atmospheric carbon dioxide concentration, otherwise there may have a risk of seeding irreversible catastrophic effects. Another research from Ken Caldeira suggested that anthropogenic carbon dioxide released in the future may need to be eliminated in order to stabilise the global-mean temperatures.

Reference:

• Mauna Loa dataset. Mauna Loa Observatory: Scripps Institution of Oceanography。 
• Caldeira, K., Matthews, H. (2008), Stabilizing climate requires near-zero emissions,Geophys. Res. Lett., 35, L04705
• Hansen, J. et al (2008). If emissions of greenhouse gases are reduced, how quickly do their concentrations in the atmosphere decrease.