Scripps scientists measured a record level of carbon dioxide in the atmosphere: 415 parts per million, on Sunday, 12 May 2019. This daily record, the Keeling Curve, is considered the foundation of modern climate change research. Geochemist Charles David Keeling joined Scripps in 1956 and built a manometer and other equipment to isolate the carbon dioxide in air samples. In 1958, the average carbon dioxide concentration of the first measurement was 316.16 parts per million. In 2013, the CO2 concentration surpassed 400 ppm for the first time in human history. Video: Scripps Oceanography

By Peter Dickrill
13 May 2019

(Science Alert) – Yet another alarming milestone of humanity’s damaging effect on the environment has now officially been reached – crossing a barrier into a hot, polluted future like the planet hasn’t witnessed in millions of years.

This weekend, sensors in Hawaii recorded Earth’s atmospheric concentration of carbon dioxide (CO2) passing 415 parts per million (ppm) for the first time since before the ancient dawn of humanity.

On Saturday, CO2 concentration recorded at the Mauna Loa Observatory in Hawaii by researchers from the Scripps Institution of Oceanography hit 415.26 ppm – the latest in a dire series of climatic thresholds being breached by a human society that refuses to relinquish the conveniences afforded by fossil fuels.

Atmospheric carbon dioxide measured at Mauna Loa Observatory, 1958-2019. This daily record of atmospheric carbon dioxide, from Scripps Institution of Oceanography at UC San Diego, is sometimes referred to as the "Keeling curve", after Geochemist Charles David Keeling. Graphic: Scripps Oceanography
Atmospheric carbon dioxide measured at Mauna Loa Observatory, 1958-2019. This daily record of atmospheric carbon dioxide, from Scripps Institution of Oceanography at UC San Diego, is sometimes referred to as the “Keeling curve”, after Geochemist Charles David Keeling. Graphic: Scripps Oceanography

“This is the first time in human history our planet’s atmosphere has had more than 415 ppm CO2,” meteorologist Eric Holthaus tweeted.

“Not just in recorded history, not just since the invention of agriculture 10,000 years ago. Since before modern humans existed millions of years ago. We don’t know a planet like this.”

It was only a few years ago that carbon pollution in the atmosphere soared past 400 ppm, and it didn’t take long much longer to reach 410 ppm (in 2017). […]

“The average growth rate is remaining on the high end,” said the director of the Scripps CO2 program, Ralph Keeling. [more]

It’s Official: Atmospheric CO2 Just Exceeded 415 ppm For The First Time in Human History