With JAXA sea ice website still on holiday, I decided to drag into my computer the Mauna Loa data, and see if I could invent a plausible Armageddon story,

**Lies, damned Lies and Statistics**

The graph below shows CO2 ppm reaching 450 ppm by 2030 using a polynomial trend line at the 4th power.

y = 7E-06x4 - 0.0587x3 + 175.04x2 - 232014x + 1E+08

**R² = 0.9936**

Note the ridiculously high R^{2 }correlation. In other words, at first sight plausible. This would require CO2 concentration to increase by about 40 ppm in 13 years, i.e. just over 3 ppm per annum, as opposed to the current increase per annum of just over 2. Increase in human CO2 emissions on this sort of scale does not seem plausible. So such a marked increase in CO2 ppm per annum would require a significant collapse in the carbon sinks (possible?) and / or large CO2 emissions from new sources, e.g. cleared rainforest peatlands (possible?).

So to my surprise, 450 ppm by 2030 may be unlikely, but definitely possible?