Scientists at the Scripps Institution of Oceanography are raising the alarm that the atmosphere has just hit a new peak in average carbon dioxide levels, at 411.66 part per million—not even because it’s a record, but because it was logged at the Mauna Loa Laboratory in Hawaii three months before the time of year when CO2 concentrations normally reach their annual high.

“Since humanity’s greenhouse gas emissions were at an all-time high last year, a new record was expected,” explains veteran meteorologist and climate hawk Eric Holthaus. “What was shocking was that it occurred so early in the year: Earth’s carbon dioxide levels typically peak in May, when the vast northern forests of North America and Asia are just beginning to green up. Setting a new record in February is ‘rare,’ according to Scripps.”

Holthaus says this year’s CO2 concentrations are expected to peak at about 415 ppm.

Scripps CO2 Group Director Ralph Keeling said the previous year’s CO2 maximum is usually surpassed in March or April, making the February result “a measure of just how fast CO2 has been rising in the past months”. In a prepared statement, he attributed the new threshold to “the combination of weak El Niño conditions and unprecedented emissions from fossil fuel burning”.

But the bigger picture is that “there hasn’t been this much carbon dioxide in our planet’s atmosphere since before cars started clogging the roads a century ago, before agriculture was developed 10,000 years ago, and before modern humans evolved more than a million years ago,” Holthaus writes. “We have reached not only a new phase of civilizational history, but a new phase of our species’ history.”

He adds that the increase in atmospheric CO2 levels has been accelerating in recent years, “in line with scientists’ predictions of a planet creeping toward dangerous and irreversible tipping points.” That reality “highlights the dangers of collective foot-dragging on shifting to a carbon-free economy.”