Carbon dioxide concentration level at key monitoring site reaches record high

The concentration of carbon dioxide measured in that atmosphere at a National Oceanic and Atmospheric Administration monitoring station in Hawaii reached a record high late last week.

“On May 9, the daily mean concentration of carbon dioxide in the atmosphere of Mauna Loa, Hawaii surpassed 400 parts per million (ppm) for the first time since measurements began in 1958,” according to a statement from the NOAA, which is based in the United States.

The organization added that its independent measurements and those from the Scripps Institution of Oceanography were also approaching that level throughout last week.

“(The level) marks an important milestone because Mauna Loa, as the oldest continuous carbon dioxide (CO2) measurement station in the world, is the primary global benchmark site for monitoring the increase of this potent heat-trapping gas,” according to NOAA.

The NOAA says that CO2, emanating from fossil fuel burning and other human activities, is the most significant greenhouse gas contributing to climate change. The concentration of CO2 has been increasing every year since scientists began taking measurements at the Mauna Loa volcano in the 1950s, the organization said.

The rate of increase has also sped up, from about 0.7 ppm per year in the late 1950s to 2.1 ppm per year during the last decade, the NOAA says.

“That increase is not a surprise to scientists,” noted NOAA senior scientist Pieter Tans, with the Global Monitoring Division of NOAA’s Earth System Research Laboratory in Boulder, Colorado. “The evidence is conclusive that the strong growth of global CO2 emissions from the burning of coal, oil, and natural gas is driving the acceleration.”

Prior to the Industrial Revolution in the 19th century, global average CO2 was about 280 ppm, according to the NOAA.

Similar increases of CO2 have been recorded around the world by many international scientists, the NOAA notes. Last year, the NOAA reported that all Arctic sites in its air sampling networking reached 400 ppm for the first time.

“These high values were a prelude to what is now being observed at Mauna Loa, a site in the subtropics, this year,” the organization says. “Sites in the Southern Hemisphere will follow during the next few years.

The increase in the Northern Hemisphere is always a little ahead of the Southern Hemisphere because most of the emissions driving the CO2 increase take place in the north.”