11/10/2004

CO2 levels soar

An unexplained and unprecedented jump in Carbon Dioxide levels have sparked fears that we may be on the brink of runaway global warming.

During the nineties CO2 levels increased by an average of 1.5 parts per million (ppm) a year. During 2002 and 2003 however, this rate of increase has jumped to 2.08 ppm and 2.54 ppm, respectively.

In the past such rises have been attributed to natural weather phenomena such as El Nino – a disruption in the trade winds that occurs when the Pacific warms up. During El Nino years 1973, 1988, 1994, and 1998, for example, CO2 level measurements recorded unusual increases higher than 2 ppm. However, neither of the previous years have been El Nino years, and there has been no corresponding jump in terrestrial emissions from power stations and cars.

Scientists believe the jump could signal a startling decline in the ability of the Earth’s natural systems to absorb CO2. This may be evidence of “positive feedback” mechanisms at work, whereby increasing levels of CO2 in the atmosphere trigger the release of even more carbon – from ‘carbon sinks’ such as forests or peat bogs.

Earlier this year The Independent reported on the unexpected release of CO2 from the world’s peat bogs (Peat Bog Gases Accelerate Global Warming, 8th July). The article was based on findings published in the scientific journal Nature, which found that the CO2 being released from peat bogs is accelerating at a rate of 6 per cent per year. Scientists believe the dramatic increase in CO2 concentrations over recent decades, has destabilised the carbon locked up in peat bogs. This is direct evidence of a “positive feedback” mechanism, and a warning sign that time for action is running out.

Before the industrial age atmospheric concentrations of CO2 were steady at around 280 ppm. When Kyoto was drawn up in 1997, CO2 levels were 369 ppm. This year, average concentrations reached 379 ppm. Charles Keeling, who began recording CO2 concentrations in 1958 said : “The rise in the annual rate to above two parts per million is a real phenomenon. It is possible that this is merely a reflection of natural events like previous peaks in the rate, but it is also possible that it is the beginning of a natural process unprecedented in the record ”.

Tom Burke, visiting professor at Imperial College London said: “ If there is a change in the rate, the likelihood is that we have less time to take action. We are not taking the right action at the moment. We are not investing in low carbon technologies.”
The clock is ticking.

Sources

Global Warming Clock Ticks Faster, The Telegraph, 11th October
New Climate Fears As Gas Levels Soar, The Guardian, 11th October
Surprise CO2 Rise May Speed Up Global Warming, The Independent, 11th October
Peat Bog Gases Accelerate Global Warming, The Independent, 8th July

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