Global CO2 levels break 400ppm milestone

Monthly Carbon dioxide (CO2) concentrations have reached 400 parts per million across the entire globe for the first time.

The US National Oceanic and Atmospheric Administration (Noaa) collects data from air samples taken from 40 sites around the world, reported the results.

According to Noaa the CO2 levels have increased 120 parts per million since pre-industrial times and that these levels haven't been seen for about two million years.