The CO2 has surpassed the threshold of 400 ppm!
The background free-troposphere level of carbon dioxide (CO2) has surpassed the symbolically important threshold of 400 ppm (parts per million) at the Izaña Global Atmospheric Watch Observatory (2400 m a.s.l.).
This record was exceeded by the end of April coinciding with the maximum CO2 concentration annual cycle. A CO2 daily averaged mixing ratio during night period of 400.2 ppm was measured on April 29th, and 401 ppm on April 30th. Also in early May CO2 hourly values have exceeded this psychological threshold of 400 ppmv.
The concentration of CO2 registers a disturbing continued growth on global scale. The increase of greenhouse gases, of which CO2 is the most important, produces a Earth’s atmosphere warming.