Carbon dioxide passes symbolic mark

Saturday, 11 May 2013 - 8:01

Carbon+dioxide+passes+symbolic+mark

Carbon dioxide levels in the atmosphere have broken through a symbolic mark.

 

Daily measurements of CO2 at a US government agency lab on Hawaii have topped 400 parts per million for the first time.

 

The station, which sits on the Mauna Loa volcano, feeds its numbers into a continuous record of the concentration of the gas stretching back to 1958.

 

The last time CO2 was regularly above 400ppm was three to five million years ago - before modern humans existed.