The actual effect
of a doubling
of the CO2 level
on the average temperature
is unknown.
The right answer is
"We don't know".
I'd like to think if I learned anything
from all the tedious
science and math courses
I took for my BS degree,
it was that many things
in life are a mystery,
so saying "no one knows"
does not mean one is stupid.
Unfortunately,
scientists involved with
the climate feel obligated
to wild guess
the effects of CO2.
I wrote"wild guess" because there is
nothing in the global temperature record
in the past 150 years that could not be
explained by "natural climate change",
which has been happening for 4.5 billion
years.
No honest person could point to
the mild global temperature changes
since 1950, and claim "that had to be"
caused by man made CO2".
Unfortunately modern climate "science"
is filled with dishonest people
who declare and predict
whatever the governments
who pay them want to hear.
Just like scientists hired by cigarette
companies were paid to claim cigarettes
were safe to smoke.
The only good news about all the
wild guesses on the effects of CO2
is that the guesses have been declining
over time ( CO2 causes less warming ).
Unfortunately, all of the guesses are
for CO2 warming are at a rate higher than
the actual rate of warming since 1950
even if you assume the worst case,
with no proof that assumption is true,
that CO2 caused ALL the mild warming
since 1950.
That actual rate of warming,
as a worst case estimate,
is +1 degree of warming from
a doubling of CO2.
And that's worst case guess
assuming all warming is
caused by CO2 -- never mind
all the warming in the past
20,000 years, not caused by CO2,
that melted thick ice over 95%
of Canada !
A worst case of about
+1 degree of warming
in the next 200 years,
assuming CO2 levels
keep rising
at the current rate
of +2ppm per year.
That worst case estimate
means CO2 is totally harmless.
There is no logical reason
to worry about CO2, or study it.
But we cant have that,
can we?
There are leftist political motives
to demonize CO2, and then claim
only a more powerful government
can prevent a catastrophe !
That's an easier way to sell socialism
than the truth: Slower economic growth
and higher unemployment than
with a free-market economy !
More effective to claim
that a more powerful
government is needed
"to save the Earth
for our children"
-- that's scientific nonsense,
but feels good to leftists
The fact that
almost all
"climate scientists",
almost all of them
on government payrolls,
claim more than
+1 degree of warming,
from a doubling
of the CO level,
means
modern climate science
is junk science.
Svante Arrhenius' 1896 calculations
on the effect of carbon dioxide (CO2)
on global warming are frequently cited
by proponents of Anthropogenic (man made )
Global Warming.
His laboratory experiments are evidence
it was "known" more than 100 years ago
that catastrophic warming would occur
due to a rise in atmospheric CO2.
Arrhenius first paper (1896) was directed
mainly towards determining the influence
of carbon dioxide—which he called
’carbonic acid’ — on global cooling.
The temperature change from
doubling the CO2 concentration
in the atmosphere was predicted
to be potentially as high as
+5 or +6 °C.
Much discussion took place
among scientists
over the following years
about the similar effect
of water vapor
in the atmosphere.
In 1906, Arrhenius wrote that CO2
would cause much less warming than
he had guessed in 1896,
and the global warming
would be beneficial.
He published a paper in German,
never translated at the time,
or widely distributed, though
many European scientists h
ad read it.
What follows are quotes
from the 2014
Friends of Science Society
English translation of Arrhenius’
1906 paer.
http://www.friendsofscience.org/assets/documents/Arrhenius%201906,%20final.pdf
The paper,
even after translation
is difficult to read,
and like most
real scientists,
Arrhenius admits to
many uncertainties.
Arrhenius’ revised view was
a doubling of CO2 would cause
+1.6 to 3.9 °C. of warming.
The effect of CO2
and water vapor
on the atmosphere
is still unknown today
-- the science
is not settled.
The IPCC currently claims
a doubling of CO2 levels
would cause
+3.0 degrees C. warming
of the average temperature,
+/- 1.5 degrees C.
The IPCC has used those numbers,
without revisions, since 1988,
and they were also prominent
in the 1979 Charney Report.
The "official government
bureaucrat declared warming
from a CO2 doubling estimate"
has not changed since 1979,
and similar to a scientist's guess
in 1906.
In 1906 Arrhenrus wrote:
"I wish to point out that
under the (my) old calculations,
a decrease in the amount of CO2 by 50%
would cause a decrease in temperature
of 4 degrees C (1897)
and 3.2 degrees C (1901),
respectively."
"In a similar way, I (now) calculate
that a reduction in the amount of CO2
by half, or a gain to twice the amount,
would cause a temperature change
of – 1.5 degrees C., or + 1.6 degrees C.,
espectively."
"In these (my old) calculations,
I (had) completely neglected
the presence of water vapour
emitted into the atmosphere."
"We know far less about
the heat absorption by water vapour
than we know about heat absorption
by CO2."
"Tyndall’s findings*, that the
smallest amount of water vapour
sufficed to elicit a strong absorption
of radiant heat, are in contradiction
with the results of the application
of Bouguer’s formulas
used with Langley’s data."
"The water vapour in the atmosphere
does not only keep back
the Earth’s radiation, but also absorbs
a large part of the solar radiation."
"I have not considered it necessary
to make a more detailed statement
with the present data concerning
the heat absorption, since these
must be completed in many areas
before it is worthwhile to make
wider-sweeping calculations."
" ... animals can very well tolerate
CO2 concentrations in the air of 1%
or about thirty times the present amount,
and such high concentrations
are not needed to explain
the climate warming observations."
Reference is made to the work
of Chamberlin* and Frech*
regarding the possibility
of combining the carbon dioxide
theory with geological facts.