[+/-] Has runaway global warming begun?

Holy crap! This is not the kind of news you want to wake up to on a Monday morning.

An unexplained and unprecedented rise in carbon dioxide in the atmosphere two years running has raised fears that the world may be on the brink of runaway global warming.

Climatologists are bewildered why the quantity of the main greenhouse gas has leapt in a two-year period and are concerned that the Earth's natural systems are no longer able to absorb as much as in the past.

The figures could be the first sign of the breakdown in the Earth's natural systems for absorbing the gas, heralding the so-called "runaway greenhouse effect", where the planet's soaring temperature becomes impossible to contain. As the icecaps melt, less sunlight is refected back into space from ice and snow, and bare rocks begin to absorb more heat. This is already happening.

One of the predictions made by climate scientists in the Intergovernmental Panel on Climate Change is that as the Earth warms, the absorption of carbon dioxide by vegetation - known as "carbon sink" - is reduced.

Dr Piers Forster, senior research fellow of the University of Reading's Department of Meteorology, said: "If this is a rate change, of course it will be very significant. It will be of enormous concern, because it will imply that all our global warming predictions for the next hundred years or so will have to be redone."