The project of t he Greenhouse gases Observing SATellite "IBUKI" (GOSAT), the world’s first satellite designed specifically for monitoring greenhouse gases from space, is jointly promoted by the Ministry of the Environment, Japan, the National Institute for Environmental Studies, and Japan Aerospace Exploration Agency. The satellite has been in operation since its launch on January 23, 2009. The whole-atmosphere monthly mean concentration of carbon dioxide (CO2), calculated by using GOSAT data that reflect CO2 levels in all layers of the atmosphere, was found to have reached 398.8 ppm in May 2015, while showing seasonal oscillation and yearly rise over the analyzed period. It was also confirmed that the trend line of the whole-atmosphere CO2 mean, derived by removing averaged seasonal fluctuations from the monthly CO2 time series, had reached 398.2 ppm in July 2015. The trend line is expected to exceed 400 ppm within the year 2016, given that the rising trend continues. The GOSAT observation elucidates for the first time that CO2 concentration averaged over all layers of the atmosphere will soon reach the level of 400 ppm, and demonstrat es the importance of global greenhouse gas monitoring from space.
PDF here
