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 29^th, and 401 ppm on April 30^th. 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.