Carbon Dioxide Concentration in the Earth’s Atmosphere Has Hit Levels Unseen for 3 Million Years

The concentration of carbon dioxide in the Earth's atmosphere has reached levels not seen for 3 million years, scientists at Mauna Loa Observatory in Hawaii said Monday – offering a dire warning about the impact of human activity on the planet.

The observatory's sensors registered carbon dioxide levels of 415 parts per million (ppm) on Saturday, meaning CO2 made up 415 of ever 1 million molecules of gas in the atmosphere.

The concentration of carbon dioxide in the Earth's atmosphere has reached levels not seen for 3 million years, scientists at Mauna Loa Observatory in Hawaii said Monday – offering a dire warning about the impact of human activity on the planet. The observatory's sensors registered carbon dioxide levels of 415 parts per million (ppm) on Saturday, meaning CO2 made up 415 of ever 1 million molecules of gas in the atmosphere.