On Apr 21, 6:59 pm, Cato wrote:
http://www.iarc.uaf.edu/highlights/2...rth_recovering...

Is the Earth still recovering from the "Little Ice Age"?
A possible cause of global warming
Syun-Ichi Akasofu
International Arctic Research Center
University of Alaska Fairbanks
Abstract
There seems to be a roughly linear increase of the temperature from
about 1800, or even much earlier, to
the present. This warming trend is likely to be a natural change; a
rapid increase of CO2 began in about
1940. This trend should be subtracted from the temperature data during
the last 100 years. Thus, there is a
possibility that only a fraction of the present warming trend may be
attributed to the greenhouse effect
resulting from human activities. This conclusion is contrary to the
IPCC (2007) Report, which states that
"most" of the present warming is due to the greenhouse effect. One
possible cause of the linear increase
may be that the Earth is still recovering from the Little Ice Age. It
is urgent that natural changes be
correctly identified and removed accurately from the presently on-
going changes in order to find the
contribution of the greenhouse effect.
1. Introduction
There are many documents that suggest that the period between 1500 and
1900 was relatively
cool, at least in Europe; the River Thames was frequently frozen in
1676 and in the later part of
the 17th century (Lamb, 1982). Stories of the exploration of the
Northwest Passage also hint that
sea ice conditions in northern Canada in the latter part of the 1800s
were much worse than
conditions today. It is now possible to cruise the passage without
much assistance by icebreakers.
Although there is some doubt about the exact timing of the "Little Ice
Age," it is possible to infer
that the period between 1500 and 1900 was relatively cool in many
parts of the world, including
Alaska (cf. Lamb, 1982; Gribbin (ed.), 1978; Crowley and North, 1991;
Burroughs, 2001;
Serreze and Barry, 2005).
Climate change during the last 100 years or so has been intensely
discussed over the last few
decades. However, it is important to recognize that as far as the
basic global warming data for
this period are concerned, all we have is what is illustrated in the
top of the diagram of Figure 1.
The IPCC Reports state that the global average temperature increased
about 0.6°C (~1°F) during
the last 100 years. Their interpretation may be illustrated in the
second diagram of Figure 1.
Certainly, both the temperature and the amount of CO2 in the air have
increased during the last
100 years or so. Further, it is well known that CO2 causes the
greenhouse effect; therefore, it is
natural to hypothesize that CO2 is a cause of the present warming
trend.
However, there is so far no definitive proof that "most" of the
present warming is due to the
greenhouse effect, as is stated in the recently published IPCC Report
(2007). In fact, the
relationship between air temperature and CO2 is not simple. For
example, the temperature had a
2
cooling trend from 1940 to about 1975, in spite of the fact that
atmospheric CO2 began to
increase rapidly in about 1940, as can be seen in Figure 1.
In this note, it is pointed out that it is not possible to determine
the percentage contribution of the
greenhouse effect that is a direct result of human activities, unless
natural causes can be
identified and subtracted from the present warming trend.
( The rest of the article is available at the link posted above.)

Let Hear It For The :

hockey stick,

Hockey Stick.

HOCKEY STICK !

and that's my global warming 'schtick' for the day ~ RHF
.
OBTW - "The Antenna Wire Weather Report" for here in
Twain Harte, CA -for- This very Early Morning (3 AM) is
http://en.wikipedia.org/wiki/Twain_Harte%2C_CA
"WET" cause it's Raining; and it is Snowing up above
http://www.wunderground.com/US/CA/Twain_Harte.html
high in the Sierra Nevada Mountains.
SIERRAS = http://en.wikipedia.org/wiki/Sierra_Nevada_(US)

.
.
.. .