[extropy-chat] Ice cores show warming 'natural' (or not)
thespike at satx.rr.com
Fri Jan 6 23:46:07 UTC 2006
HUNDREDS of thousands of years worth of climate records in ice cores show
there is nothing unusual in a global warming trend over the past 25 years.
Marine geophysicist Bob Carter, a professor at Queensland's James Cook
University and leading climate change sceptic, said the effects of human
activity would barely register in the long-term history of climate change.
He told The Weekend Australian that ice cores from Antarctica "tell us
clearly that in the context of the meteorological records of 100 years, it
is not unusual to have a period of warming like the one we are in at the
Dr Carter disputed the theory that human activity was making a current -
natural - warm period hotter: "Atmospheric CO2 is not a primary forcing
agent for temperature change." He argues that "any cumulative human signal
is so far undetectable at a global level and, if present, is buried deeply
in the noise of natural variation".
Fellow sceptic William Kininmonth, a former director of the Bureau of
Meteorology's National Climate Centre, agreed. He wrote in a 2004 book,
Climate Change: A Natural Hazard that there was "every reason to believe
that the variabilities in global temperature and other climate
characteristics experienced over the past century are part of the natural
variability of the climate system and are not a consequence of recent
But other leading scientists, who blame human activity for climate change,
say the "denialists" are a one-to-99 minority.
Will Steffen, director of the Centre for Resource and Environmental Studies
at the Australian National University, said: "There is no debate. The
debate is over." The evidence that human activity had increased emissions
of carbon dioxide into the atmosphere, adding to natural warming, was
"overwhelming", he said.
For scientist and University of Adelaide academic Tim Flannery there was
also no argument: humans had turned up the heating and only humans could
keep a lid on it. The argument that human activity did not contribute to
global warming was "not a credible hypothesis to build policy on", he said.
© The Australian
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