Climate Home: Farewell then, 400 parts per million.
The past 12 months have seen a record surge in carbon dioxide emissions say scientists, driven by the burning of fossil fuels and boosted by a rampant El Nino phenomenon.
Tropical forests and plants that once would have been expected to reduce global CO2 levels by September have suffered badly under this El Nino, reducing their ability to soak up carbon.
That means the iconic milestone of 400 parts of carbon dioxide in every million molecules of air...