Global concentration of carbon dioxide has passed a monthly high of 400 parts per million, the first time this has happened since records began.
Scientists at the US National Oceanic and Atmospheric Administration (Noaa) said it was a “significant” but inevitable milestone. The last time CO2 regularly rose above 400ppm was three to five million years ago, long before humans existed. The latest data suggests global warming will continue to worsen, despite fossil fuel emissions levelling off.
By: James Temperton,
