The oceans are threatened by acidification due to an increase in CO levels.

Since the 1950s, both the atmospheric CO level and obesity levels have increased sharply.

Severe increases in CO levels can lead to respiratory arrest.

CO levels were then about 760 ppm and had been decreasing from earlier levels in the thousands of ppm.

Junipers also benefit from the increased CO levels, unlike the grasses with which they compete.

During unoccupied times in typical office buildings, for example, the CO levels inside drop to that of outside air.

Today, CO levels are monitored at about 100 sites around the globe.

Currently, CO levels are 40% higher than they were in pre-industrial times.

So, hyperventilation is induced in the patients in order to increase their CO levels that produce some of this symptoms.

It is notable, however, that CO levels will have risen by the time this could be achieved.