Re: [asa] Rush Limbaugh Science Lesson

On Wed, May 28, 2008 at 11:14 AM, Rich Blinne <rich.blinne@gmail.com> wrote:

>
>
> On Wed, May 28, 2008 at 10:18 AM, Lynn Walker <lynn.wlkr@gmail.com> wrote:
>
>>
>> This sounds pretty much like what you wrote in your notes, so why do you
>> think he is misleading people?
>>
>>
> There is a very fundamental error in Rush's calculation. Even if you had a
> basic background in physics you should be able see it. Hint: With respect to
> Earth v. Mars v. Venus v. Mercury what's is different about them that would
> explain the respective temperatures of *all* of these planets. Another hint:
> Think about Rush's use of percentages. Third Hint: What are the units of CO2
> used in climate science?
>

Times up. Pencils down. The relationship between CO2 and temperature was
discovered by Svante Arrenhius via his computer models. :-) If you don't get
the joke note that his was in 1896!! It's known as a climate sensitivity.
For Earth, the equilibrium climate sensitivity is 3 degrees C when CO2 is
doubled. CO2 levels are over 30% more than what they were in the mid-19th
Century and are at their highest level in at least 800000 years.

The physics mechanism is gases absorb radiation at different frequencies
based on their chemical bonds. By the mid-20th Century satellites started
being used for meteorology. The question arose was was the measured warming
that was happening even back (there were papers on global warming in the
1930s) then caused by CO2 or water vapor which is also a greenhouse gas? The
absorption frequencies differ between water and CO2 and satellites looked
downward to check which gas was the culprit. The signature of CO2 from space
was clear. Also CO2 was measured from the mountains of Hawaii showing CO2
increasing at an alarming rate. This caused the president to send a special
message to Congress that warming was an environmental problem. (Bonus
question: which president am I talking about and what year? Randy can't
answer because he saw my slides.)

Back to Mars. The error Rush made was not taking into account:

1. The different distances from the Sun
2. The atmosphere of Mars is much, much thinner. (Rush even admitted this by
giving the Everest analogy)
3. Using percentages of a much thinner atmosphere.

The combined effect is to have a much lower temperature for Mars. (The lower
temperature also causes problems for Rush's it's the Sun mantra. If the Sun
is causing warming why hasn't Mars also warming similarly in the last 30
years?) If you look at Venus you see the same percentage but its atmosphere
is far thicker than either Earth's or Mars' and this is what produces the
900 degree temperatures.* It's the absolute amount and the density of the
CO2 which is the issue.* Earth and Venus have the same total Carbon except
pretty much all of Venus' Carbon is in its atmosphere. Much of Earth's
Carbon is sequestered in the ground and oceans. This is why burning fossil
fuels is such a bad idea. Take Carbon out of the ground and pump into the
atmosphere like Venus. Mercury is closer to the Sun but it has little to no
atmosphere and thus it has a cooler global average temperature than Venus
because it does not have any GHG effect.

Note the importance of theory here. Climate skeptics like their cousins ID
proponents project themselves. So, it must be just the computer models
because they have no theory and are doing curve fitting (and usually
fraudulent curve fitting and cherry picking like what Michael Crichton and
John Christy has done). The computer models are based on theory which has
explanatory power. When the computer models don't fit the forecast or
hindcast the theory is updated to account for the discrepancy. There was
cooling in the mid-20th Century that didn't fit the models. Eventually the
theory got updated to include the effect of aerosols and now the models
match the 20th Century record very well. Since 1980 the aerosol effect has
been swamped by AGW. As is the case with evolutionary biology this theory
has developed for over 100 years and has gotten better and more accurate
with time. Computer modelling has improved the quality of the science by
giving a more detailed way to falsify a theory. This improvement in the way
science is done is not merely limited to the scope of climate science. On
the other, the arbitrary hypothesizing of the climate skeptics is not
(mature) science. You need theory. It's not a curse word.

Rich Blinne
Member ASA

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Received on Thu May 29 13:21:35 2008