There is more carbon dioxide in the atmosphere than there has been for 800,000 years — since before our species evolved.
On Saturday (May 11), the levels of the greenhouse gas reached 415 parts per million (ppm), as measured by the National Oceanic and Atmospheric Administration’s Mauna Loa Observatory in Hawaii. Scientists at the observatory have been measuring atmospheric carbon dioxide levels since 1958. But because of other kinds of analysis, such as those done on ancient air bubbles trapped in ice cores, they have data on levels reaching back 800,000 years.
During the ice ages, carbon dioxide levels in the atmosphere were around 200 ppm. And during the interglacial periods — the planet is currently in an interglacial period — levels were around 280 ppm, according to NASA.
But every story has its villains: Humans are burning fossil fuels, causing the release of carbon dioxide and other greenhouse gases, which are adding an extra blanket on an already feverish planet. So far, global temperatures have risen by about 1.8 degrees Fahrenheit (1 degree Celsius) since the 19th century or pre-industrial times, according to a special report released last year by the United Nation’s Intergovernmental Panel on Climate Change.