Across the Arctic, atmospheric concentrations of carbon dioxide have reportedly reached 400 parts per million (ppm) for the first time in at least 800,000 years. Scientists have said that reaching the 400 ppm level is a troubling sign that the world is continuing to emit climate-changing greenhouse gases at an unsustainable rate.
Global concentrations of carbon dioxide, considered the most important greenhouse gas, have reached 395 ppm, but over past months the levels of CO2 have passed 400 ppm in the Arctic due to a lack of carbon dioxide-sucking vegetation in the Arctic during winter and spring.
Levels over 400 ppm have been recorded this spring in Alaska, Greenland, Norway, and Iceland. As a stark comparison, pre-industrial revolution levels of carbon dioxide were around 280 ppm.
The director of the National Oceanic Atmospheric Administration Earth’s Earth System Research lab in Colorado, Jim Butler, has said the new CO2 level is a “troubling milestone”.
Reaching the 400 ppm mark certainly isn’t a surprise, as levels have been rising at an accelerated pace. The 350 mark was passed years ago. Many scientists say 350 ppm is the top safe level for the presence of carbon dioxide in the atmosphere. Considering we are at 395 ppm globally, it’s a troubling milestone indeed.
Image credit NASA Goddard Space Flight Center/Kathryn Hansen