Just three years ago this month, the carbon dioxide monitoring station atop Hawaii’s Mauna Loa reached a significant milestone: the first measurement of CO2 concentrations that exceeded the benchmark of 400 parts per million (ppm). Now, they may never again dip below it.
“I think we’re essentially over for good,” Ralph Keeling, the director of the Mauna Loa CO2 program at Scripps Institution of Oceanography at UC San Diego, said. And before too long, that will be the case the world over. Atmospheric carbon dioxide levels are monitored at stations around the world, providing records of the mark humans are leaving on the planet. Keeling’s father, Charles Keeling, began the recordings at Mauna Loa in 1958, revealing not only the annual wiggles created by the seasonal growth and death of vegetation, but the steady rise in CO2 from year to year.