On Tuesday, the Mauna Loa Observatory recorded its first-ever carbon dioxide reading in excess of 410 parts per million (it was 410.28 ppm in case you want the full deal). Carbon dioxide hasn’t reached that height in millions of years. It stood at 280 ppm when record keeping began at Mauna Loa in 1958. In 2013, it passed 400 ppm. Just four years later, the 400 ppm mark is no longer a novelty. It’s the norm.
Carbon dioxide concentrations have skyrocketed over the past two years due to in part to natural factors like El Niño causing more of it to end up in the atmosphere. But it’s mostly driven by the record amounts of carbon dioxide humans are creating by burning fossil fuels.
“The rate of increase will go down when emissions decrease,” Pieter Tans, an atmospheric scientist at the National Oceanic and Atmospheric Administration, said. “But carbon dioxide will still be going up, albeit more slowly. Only when emissions are cut in half will atmospheric carbon dioxide level off initially.”
Even when concentrations of carbon dioxide level off, the impacts of climate change will extend centuries into the future. The planet has already warmed 1.8°F (1°C), including a run of 627 months in a row of above-normal heat. Sea levels have risen about a foot and oceans have acidified. Extreme heat has become more common.
All of these impacts will last longer and intensify into the future even if we cut carbon emissions. But we face a choice of just how intense they become based on when we stop polluting the atmosphere.
Right now we’re on track to create a climate unseen in 50 million years by mid-century.
