10.23.07
Carbon output
From Rad-Green
Carbon output rising faster than forecast, says study
Global warming ‘will come sooner and be stronger’
Chinese growth and loss of natural ’sinks’ highlighted
David Adam, environment correspondent
Scientists warned last night that global warming will be “stronger
than expected and sooner than expected”, after a new analysis showed
carbon dioxide is accumulating in the atmosphere much faster than
predicted.
Experts said that the rise was down to soaring economic development in
China, and a reduction in the amount of carbon pollution soaked up by
the world’s land and oceans. It also means human emissions will have
to be cut more sharply than predicted to avoid the likely effects.
Corinne Le Quere, a climate expert at the University of East Anglia
and British Antarctic Survey, who helped conduct the study, said:
“It’s bad news because the increase in atmospheric carbon dioxide has
accelerated since 2000 in a way we did not expect. My biggest worry is
people are discouraged by this and do nothing. I hope political
leaders will act on this, because we need to do something fast.”
The study worsens even the gloomy predictions of this year’s report
from the Intergovernmental Panel on Climate Change. The IPCC, which
shared the Nobel peace prize this month with Al Gore, said there were
only eight years left to prevent the worst effects of global warming,
by acting to curb emissions.
Dr Le Quere said: “We are emitting far more than anticipated when the
IPCC scenarios were drawn up in the late 1990s.” Global carbon dioxide
emissions from fossil fuel burning has risen by an average 2.9% each
year since 2000. During the 1990s the annual rise was 0.7%.
The new study explains abnormally high carbon dioxide measurements
highlighted by the Guardian in January. At the time, scientists were
puzzled why dozens of measuring stations across the world were showing
a CO2 spike for 2006, the fourth year in the last five to show a sharp
increase in the greenhouse gas.
Carbon dioxide concentration in the atmosphere is measured in parts
per million (ppm); from 1970 to 2000, the concentration rose by about
1.5ppm each year; since 2000 the annual rise has leapt to an average
1.9ppm.
The new study, published in the US journal Proceedings of the National
Academy of Sciences (PNAS), says three processes have contributed to
this increase: growth in the world economy, heavy use of coal in
China, and a weakening of natural “sinks” - forests, seas and soils
that absorb carbon.
Pep Canadell, executive director of the Global Carbon Project, which
carried out the research, said: “In addition to the growth of global
population and wealth, we now know that significant contributions to
the growth of atmospheric CO2 arise from the slowdown of natural sinks
and the halt to improvements in the carbon intensity of wealth
production.”
The overall growth of the economy is the only one of the three factors
accounted for in scientists’ forecasts of climate change, which means
the growth in atmospheric CO2 is about 35% larger than they expected.
About half of this is down to the Chinese reliance on coal, which has
forced up the carbon intensity of the overall world economy since
2000, reversing a trend of increasing energy efficiency since the
1970s. The rest of the rise is explained by the weakening of the
natural carbon sinks.
Scientists assume about half of human carbon emissions are reabsorbed
into the environment, but computer models predict increased
temperatures will reduce this effect. The PNAS report is the most
convincing evidence so far that the global sinks have weakened over
the last 50 years, though the large natural variations in carbon
exchange between the earth and the atmosphere mean the team can be
only 89% certain they have found an effect, short of the usual 95%
confidence required to publish scientific findings.The Guardian Tuesday October 23 2007