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[Illustrations, footnotes and references available in PDF version]
The big temperature picture. Graph and insight from Dr Syun
Akasofu
(2009 International Conference on Climate Change, New York,
March 2009).
The global temperature has been rising at a steady trend rate of 0.5°C
per century since the end of the little ice age in the 1700s (when the
Thames River would freeze over every winter). On top of the trend are
oscillations that last about thirty years in each direction:
1882 – 1910 Cooling
1910 – 1944 Warming
1944 – 1975 Cooling
1975 – 2001 Warming.
In 2009 we are where the green arrow points, with temperature leveling
off. The pattern suggests that the world has entered a period of slight
cooling until about 2030.
There was a cooling scare in the early 1970s at the end of the last
cooling phase. The current global warming alarm is based on the last
warming oscillation, from 1975 to 2001. The IPCC predictions simply
extrapolated the last warming as if it would last forever, a textbook
case of alarmism. However the last warming period ended after the usual
thirty years or so, and the global temperature is now definitely
tracking below the IPCC predictions.
The IPCC blames human emissions of carbon dioxide for the last warming.
But by general consensus human emissions of carbon dioxide have only
been large enough to be significant since 1940—yet the warming trend
was in place for well over a century before that. And there was a
cooling period from 1940 to 1975, despite human emissions of carbon
dioxide. And there has been no warming since 2001, despite record human
emissions of carbon dioxide.
There is no actual evidence that carbon dioxide emissions are causing
global warming. Note that computer models are just concatenations of
calculations you could do on a hand-held calculator, so they are
theoretical and cannot be part of any evidence. Although the models
contain some well-established science, they also contain a myriad of
implicit and explicit assumptions, guesses, and gross
approximations—mistakes in any of which can invalidate the model
outputs.
The pattern suggests that the world has entered a period of slight cooling until about 2030.
Furthermore, the missing hotspot in the atmospheric warming pattern
observed during the last warming period proves that (1) the IPCC
climate theory is fundamentally broken, and (2) to the extent that
their theory correctly predicts the warming signature of increased
carbon dioxide, we know that carbon dioxide definitely did not cause
the recent warming (see here for my full explanation of the missing
signature. The alarmists keep very quiet about the missing hotspot.
No one knows for sure what caused the little ice age or for how many
more centuries the slow warming trend will continue. It has been warmer
than the present for much of the 10 thousand years since the last big
ice age: it was a little warmer for a few centuries in the medieval
warm period around 1100 (when Greenland was settled for grazing) and
also during the Roman-Climate Optimum at the time of the Roman Empire
(when grapes grew in Scotland), and at least 1°C warmer for much of the
Holocene Climate Optimum (4 to 8 thousand years ago).
Addendum
Measuring the global temperature is only reliably done by satellites,
which circle the world 24/7 measuring the temperature over large
swathes of land and ocean. But satellite temperature records only go
back to 1979. Before that, the further back you go the more unreliable
the temperature record gets. We have decent land thermometer records
back to 1880, and some thermometer records back to the middle of the
1700s. Prior to that we rely on temperature proxies, such as ice cores,
tree rings, ocean sediments, or snow lines.
The PowerPoint and audio from Dr Akasofu’s presentation at The
International Climate Change Conference 2009 can be downloaded here
HYPERLINK "http://www.heartland.org/events/NewYork09/proceedings.html" .
Dr. David Evans was a consultant to the Australian Greenhouse Office from 1999 to 2005.
Original Source:
http://joannenova.com.au/2009/04/03/global-warming-a-classic-case-of-alarmism/
http://scienceandpublicpolicy.org/originals/another_currupt_currency.html.
http://www.heartland.org/events/NewYork09/proceedings.html.
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