World breaks carbon dioxide threshold
The planet has more of the gas in its atmosphere than it has for millions of years, after the Mauna Loa Observatory recorded its first reading of more than 410 parts per million. While that round number doesn't mean anything scientifically, and the readings have been gradually rising over recent years, they show the stunning speed at which they are shooting up. In 2013, the world passed the landmark of 400ppm, as registered at Mauna Loa. But that has quickly become a normal reading – and now those readings have passed over another milestone.
“It's pretty depressing that it’s only a couple of years since the 400 ppm milestone was toppled,” Gavin Foster, a paleoclimate researcher at the University of Southampton told the website Climate Central. “These milestones are just numbers, but they give us an opportunity to pause and take stock and act as useful yard sticks for comparisons to the geological record.” Scientists expect that the amount of carbon dioxide will keep increasing to the point that it nears 409ppm on a monthly, not just a daily, average.
Monthly averages are already quickly moving towards that point, according to data made available on the Scripps Institution of Oceanography at UC San Diego's website.