Climate modeling and proofs?

Question

The two primary underpinnings of the theory that Greenhouse warming is caused by man are : Correlative relationship between recent atmospheric CO2 contents and estimated (calculated) global temperatures; and predictive modeling that appears to be able to mimic historic trends and which indicates global warming shall result from the continuation of increasing CO2 (climate forcing concept). Convince me please, if you would, that the correlative relationship is causative and not coincidental or a secondary association; and convince me that climate models are reasonably accurate for predictive purposes. As to the former, I find there is a large disconnect between the two parameters, particularly outside the timeframe of the industrial revolution, and I find that the second, at least for short term climate prediction, has a very poor accuracy to date (I am not confusing weather with climate either). Have fun. I know some of you will love to set me straight.

Answer 1

Re the historic disconnect.  There are many factors that have altered climate historically.  But those other factors (particularly solar radiation) have been relatively constant recently, so greenhouse gases have risen to the fore.

Re the models.  Related to the above the models flat don't work, unless you include the parameter of greenhouse gases.  In statistical terms the "signal" from greenhouse gases is very strong.

Also, a wide variety of models (some listed below), and a wide variety of assumptions within the model, all yield the same result.  Also in statistical terms, the models are "robust".

All this is why:

EVERY major scientific organization has issued an official statement that this is real, and mostly caused by us.  The National Academy of Sciences, the American Association for the Advancement of Science, the American Institute of Physics, the American Chemical Society, the American Geophysical Union, the American Meteorological Association, etc.

Models:

Table 4. AOGCMs in the Intercomparison

Originating Group Country           Model

BCCR Norway                         BCCR-BCM2.0

CCCma Canada                        CGCM3.1(T47/T63)

CCSR/NIES/FRCGC Japan               MIROC3.2(medres/hires)

CNRM France                         CNRM-CM3

GFDL USA                            GFDL-CM2.0/2.1

GISS USA                            GISS-EH/ER

INM Russia                          INM-CM3.0

IPSL France                         IPSL-CM4

LASG/IAP China                      FGOALS-g1.0

MIUB/METRI/KMA Germany/Korea        ECHO-G

MPIfM Germany                       ECHAM5/MPI-OM

MRI Japan                           MRI-CGCM2.3.2

NCAR USA                            CCSM3

NCAR USA                            PCM

UKMO UK                             HadCM3

UKMO UK                             HadGEM1

Answer 2

there are a couple of comments.

first, are you really expecting science here?

really?

concerning models, they're fairly easy to verify.

you put data in from 1950-1960, and then see how well they predict the weather that occurred from 1960 to 1970.

you can do that for every decade, and see how well the results correlate to the weather that we already know has occurred.

if they're accurate, then there is no reason to assume that all of a sudden, for the next few years, they will be wrong.

as to whether it's just accidental, or there is a causal relationship, why don't we look at why there is a cause.

http://www.nasonline.org/site/PageServer

"May 19, 2008: The National Academies have released the 2008 edition of "Understanding and Responding to Climate Change," a free booklet designed to give the public a comprehensive and easy-to-read analysis of findings and recommendations from our reports on climate change."

http://dels.nas.edu/dels/rpt_briefs/clim...

not difficult to understand, if one is inclined to do so.

the real problem is that there are an awful lot of folks who are just not interested in understanding.

Answer 3

The greenhouse effect (heat trapping of gases like CO2) was discovered in the 19th century (no computer models required) and became well understood during the mid-20th century.  It's well established physics that isn't even being debated.  There was little concern, at first, because it was never imagined that human activity would ever result in sufficient emission levels to exceed the planets absorption rate (which we now know was wrong, since we've already achieved a 30% increase in atmospheric CO2 levels).

The models value comes in their predictive ability, not in demonstrating correlation of past temperatures (that's basically done as a calibration tool).  People tend to confuse the known physics of CO2 heat trapping and the output of models.  Models go far beyond the radiative effect of CO2 and attempt to account for many other climate complexities (e.g. feedback).

Answer 4

1) The temperature increase between 2001 and 2007 were consistent with IPCC projections of greenhouse gas-driven warming made in previous reports dating back to the 1990s.

2) Geographic differences in concentrations reveal that sources occur predominantly over land in the more heavily populated Northern-Hemisphere.

3) The CO2 isotopes, which can distinguish among sources of emissions, demonstrated that the majority of CO2 increase comes from combustion of fossil fuels.

Answer 5

No problem.

#1 - it's called the greenhouse effect.  More atmospheric CO2 (or any other greenhouse gas) means more warming.  There's your causation.

For an explanation as to why historical warmings preceeded CO2 increases, see the 'Carbon dioxide feedbacks' section here: http://greenhome.huddler.com/wiki/global...

#2 - Modern climate models have been used for 20 years now, and have proven to be quite accurate in their global temperature change predictions:

http://www.realclimate.org/index.php/arc...

http://www.realclimate.org/index.php/arc...

Not to mention the fact that as you mentioned, they've been able to accurately hindcast the global temperature changes of the 20th century:

http://www.globalwarmingart.com/wiki/Ima...

Answer 6

What the Modelers threw out = UV effects on Atmosphere.

The energy emissions from the sun vary, especially in the UV range.

Even NASA admits this: Quote:

"Sunspot cycle: ozone is created by solar UV radiation. The amount of UV radiation produced by the sun is not constant but varies by several percent in a roughly 11year cycle."

http://www.nas.nasa.gov/About/Education/...

Quote From the Weather Experts - Intellicast

"While irradiance changes just 0.1% over the 11 year cycle, ultraviolet radiation changes 6 to 8% and shorter wavelengths even more."

http://www.intellicast.com/Community/Con...

This 6-8% increase of UV heats the Atmospheres & Oceans which in turn releases CO2 from the LARGEST repository of CO2. The heated oceans drive the earth's climate/weather = El Nino, La Nina.

We have had over 100 years of active Sun (Now a Very Quiet Sun) which has caused the so called GW/Climate Change.

See Active Sun:

http://spaceweather.com/glossary/sunspot...

We are now headed into La Nina - Cooling Oceans which will bring Colder weather and likely more severe storms. But with the cooler oceans, CO2 levels should start falling in several months. The oceans hold about 90% of the CO2 on earth - and no one can guess what lies below.

The Relationship of the PDO to El Nino and La Nina Frequency

http://www.intellicast.com/Community/Con...

Watch for the Thumbs Down from the kids!

Edit:  

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