Atmospheric carbon last year reached levels not seen in 800,000 years

The concentration of carbon dioxide (CO 2 ) in Earth’s atmosphere reached 405 parts per million (ppm) last year, a level not seen in 800,000 years, according to a new report. It was also the hottest year on record that did not feature the global weather pattern known as El Niño, which is driven by warmer than usual ocean waters in the Pacific Ocean, concludes the State of the Climate in 2017, the 28th edition of an annual compilation published by the National Oceanic and Atmospheric Administration (NOAA). Overall, 2017 ranked as the second or third warmest year, depending on which measure is used, since researchers began keeping robust records in the mid-1800s.

Even if humanity “stopped the greenhouse gasses at their current concentrations today, the atmosphere would still continue to warm for next couple decades to maybe a century,” said Greg Johnson, an oceanographer at NOAA’s Pacific Marine Environmental Laboratory in Seattle, Washington, during a press call yesterday about the report.

The hefty document includes data compiled by 524 scientists working in 65 countries. A few highlights: