Atmospheric CO2 Concentrations in Japan Rise above 400 ppm in 2012, First Time on Record

The Japan Meteorological Agency (JMA) announced on May 16, 2012, that the monthly average concentration of atmospheric carbon dioxide (CO2) exceeded 400 parts per million (ppm) at one of the three greenhouse gas monitoring stations in Japan for the first time since the JMA started CO2 monitoring in 1987. The preliminary figures (Note 1) stood at 401.2 ppm in March and 402.2 ppm in April in Ryori, Ofunato City, Iwate Prefecture.

The JMA has been monitoring CO2 concentrations in the atmosphere in Ryori, Ofunato City, Iwate Prefecture; Minamitorishima Island, Ogasawara Village, Tokyo; and Yonaguni Island, Yaeyama County, Okinawa Prefecture. Monthly average figures marked record highs in April 2012 also in Minamitorishima and Yonaguni, at 398.1 ppm and 399.4 ppm, respectively.

Annual average figures in 2011 were also at an all-time high: 394.3 ppm in Ryori (Note 2), 392.8 ppm in Minamitorishima, and 394.4 ppm in Yonaguni.

Note 1: Both the monthly and annual data are preliminary figures. Final figures will be announced later based on more detailed calculation. The difference between preliminary and final figures is expected to be about 0.1 ppm at most.

Note 2: The April 2011 data at Ryori was not available due to the damage caused by the Great East Japan Earthquake on March 11 in the same year. Therefore, the 2011 annual average in Ryori was estimated from the average of data in 11 months except April.

Posted: 2012/08/18 06:00:15 AM