The concentration of carbon dioxide in the atmosphere has
reached a record high, according to the latest figures, renewing
fears that climate change could begin to slide out of control.
Scientists at the Mauna Loa observatory in Hawaii say that CO2
levels in the atmosphere now stand at 387 parts per million
(ppm), up almost 40% since the industrial revolution and the
highest for at least the last 650,000 years. The figures,
published by the US National Oceanic and Atmospheric
Administration on its website, also confirm that carbon dioxide,
the chief greenhouse gas, is accumulating in the atmosphere
faster than expected. The annual mean growth rate for 2007 was
2.14ppm - the fourth year in the last six to see an annual rise
greater than 2ppm. From 1970 to 2000, the concentration rose by
about 1.5ppm each year, but since 2000 the annual rise has leapt
to an average 2.1ppm. Scientists say the shift could indicate
that the Earth is losing its natural ability to soak up billions
of tonnes of CO2 each year. Climate