latest CO2 level

The latest measurement of the CO2 levels in the atmosphere is 387 ppm, measured at Mauna Loa.

Then this journalist goes on to write:

The level is just a few years from what many scientists regard as the tipping point of 400ppm.

Oh Man. I am really starting to hate this term "tipping point." There is absolutely no science or calculation -- none whatsoever -- that demonstrates any "tipping" phenomenon at 400 ppm. It's only an ominous number because humans happen to have 10 fingers. That's it.