The atmospheric carbon dioxide levels have reached a milestone during the past weekend. An alarming 415 ppm (parts per million) was detected on the scales.

The high level of carbon dioxide was recorded by the Mauna Loa University in Hawaii and was announced by Scripps Institution of Oceanography via social media. The first time that a daily level has topped 415 ppm was recorded on Saturday with the exact reading of 415.26 ppm, taken during the regular update of carbon dioxide levels.

Comment from Ralph Keeling, director of Scripps CO2 Program: “The average growth rate is remaining on the high end. The increase from last year will probably be around three parts per million whereas the recent average has been 2.5 ppm....” 1/2 — Keeling_Curve (@Keeling_curve) May 12, 2019

800,000 years before the industrial revolution, the carbon dioxide levels did not even reach 300 ppm. Computer models used in a study conducted in April has confirmed that carbon dioxide levels today are all the highest observed in the last three million years. The computer models have also shown that the current levels could have been at only 280 ppm if it weren't for the burning of fossil fuels.

It was about 5.3 to 2.6 million years ago when carbon dioxide levels were last known to reach this high level. During that time, the Pliocene epoch, the sea levels were 20 meters higher and the temperatures were 3°C to 4°C warmer as beech trees grew in Antarctica.

Last year, May 2018, the Mauna Loa observatory recorded carbon dioxide levels that reached 410 ppm for the first time.

In 1958, Charles David Keeling was the first to take a reading from the volcanic observatory. After he died, his son, Ralph Keeling continued his work. The collaborative efforts have resulted in the so-called Keeling curve which documents 61 years' worth of data showing the rise of carbon dioxide from the initial reading of 313 ppm in March 1958.

Keeling, who directs the Scripps carbon dioxide has stated that the average growth rate is remaining on the high-end. He added that an increase from the previous year would be computed at around three ppm, as compared to the recent average which has been 2.5 ppm. Keeling explained that this could be caused by the effects of mild El Niño conditions in addition to the long-running and increased use of fossil fuel.

In 2018, the energy-related carbon dioxide emissions have reached a record high of 33.1 gigatons (Gt) of greenhouse gas. That is 1.7% more from the year before.

The alarming news has spread via social media where many users including some big names have expressed their worries about the current condition of the planet. Among these were climate action advocate and meteorologist Eric Holthaus and 350.org founder Bill McKibben.