On 10 May 2013 US federal agency National Oceanic and Atmospheric Administration, NOAA made an announcement that the official US Government measuring station (Mauna Loa Observatory) in Hawaii recorded CO2 concentration has crossed 400 ppm (parts per million) or 0.04% for… Read moreThe atmospheric concentration of CO2 is over 400 PPM. What do we understand from this in common man’s lingo?