Back in late April, there was a spate of hyperventilating headlines and news reports about the increasing levels of carbon dioxide in the atmosphere.

This one in particular, from Think Progress, should have made its author so light-headed that she passed out:

The Earth just reached a CO2 level not seen in 3 million years
Levels of atmospheric carbon dioxide hit record concentrations.

That story and others were prompted by measurements at Hawaii’s Mauna Loa Observatory showing that