Geoscience Reference
In-Depth Information
3. Mauna Loa observatory atmospheric carbon dioxide measurements
This CO
2
data from the Mauna Loa observatory can be combined with the detailed work
on ice cores to produce a complete record of atmospheric CO
2
since the beginning of the
industrial revolution. This shows that atmospheric CO
2
has increased from a pre-industrial
concentration of about 280 ppmv to over 400 ppmv at present, representing an increase of
over 40 per cent. To put this increase into context, ice-core evidence shows that over the
last 800,000 years the natural change in atmospheric CO
2
has been between 180 and 300
ppmv. The variation between warm and cold periods is about 80 ppmv—less than the CO
2
pollution that we have put into the atmosphere over the last 100 years. It demonstrates that
the level of pollution that we have already caused in one century is comparable to the nat-
ural variations which took thousands of years.
