Co2 Acquittal

[freeztar]

Originally Posted by freeztar

The difference is that deep sea hydrothermal ventilation is not a defined variable at this point. I understand your argument that because it is not a defined variable, it renders all other contributions inaccurate. ...

Really?
So, with that logic, I suppose we should abandon any theory with unknown/undefined variables?

I have little trust in most peoples' knowledge of the math involved in modeling a complex system.

Nor do I, but "most people" don't really hang around these parts.
I certainly cannot claim an ability to construct one of these models, but I have studied several different ones and understand the principles governing them. I'm not an expert and as such, I appeal to those that possess the utility to construct and run these models. If you have some insight into the specifics of the climate models Turtle, then I'm sure that could make for a great thread.

I'm talking about the general case here. I directed that quote to whatever specific cases it applies to. You said elsewhere you are in the anthropogenic camp; the quote is for that group. If the shoes fit, wear them; if not, don't.

I always make sure my shoes fit.
Although sometimes the back of the shoe tends to grate my heels. (but that's neither here nor there)

Here's a word or three on the unreliablility (reliability?) of the current computer modeling of climate. Never mind some of these models take five months to do a single run.

Climate models are inherently unreliable and are time consuming.
Hmm...I see your point. Let's quit modeling altogether, it's pointless. We can never model reality...

Not to worry, it's covered by your carbon credits.

What carbon credits?
Oh, you mean the nurturing of the Earth by promoting plant life and general sustainability?
I guess I don't know much about such things...

[Turtle]

Originally Posted by freeztar

Climate models are inherently unreliable and are time consuming.
Hmm...I see your point. Let's quit modeling altogether, it's pointless. We can never model reality...



What carbon credits?
Oh, you mean the nurturing of the Earth by promoting plant life and general sustainability?
I guess I don't know much about such things...

The first paragraph is an emotional appeal to a false premise.

On the second, your company is excepted of course Charcoal Brother.

[Chris C]

A few points--

turtle,

Global Warming by definition is just ΔT, not absolute T, so you need to look at drivers of climate change which can initiate a change from state 1 to state 2, and water vapor cannot do that. Then, you can look at 'feedbacks' (or what changes as a reaction to climate change which amplifies or dampens the original forcing). The realclimate article is an easy-to-understand way of saying that the "saturation vapor pressure" goes up or down as a function of temperature. Water vapor is a rather weak absorber near the planck function for Earthlike temperatures, and is more or less controlled by CO2 as WV impact is temperature dependent so if you remove all the CO2 then the water vapor impact will decrease exponentially since it condenses in a cooler climate. Gaseous H20 has a very short residence time in the atmosphere (~10 days; CO2- centuries to millennia), and also, there is a lot less WV as you go up to the higher, colder, lower pressure part of the atmosphere where the Earth's heat balance is determined. It takes two to tango, so even though WV is helping keep the planet warmer than CO2 is, that impact is very much CO2-dependent, and the CO2 impact is still non-negligible (about 30 W/m^2 of the 150 W/m^2 of outgoing energy that gets absorbed by the greenhouse effect).

As for numbers, WV actually makes up about 2/3 of the longwave radiation absorbed by the atmosphere (table 3; http(www).cgd.ucar.edu/cas/Trenberth/trenberth.papers/KiehlTrenbBAMS97.pdf ). I think the impacts in units W/m^2 by quantifying the role in the greenhouse effect or change in greenhouse effect is the best way to look at it. For example, doubling the atmospheric CO2 has a radiative forcing of 4 W/m^2, and so at equilibrium you go from around 150 W/m^2 absorbed by the atmosphere to about 170 W/m^2. A change from 280 to 380 ppmv is not 0.00X percent, and this is where bad logic of small percentages should stop. A good first step is recognizing that ~99% of the atmosphere (O2, N2, Argon) do not contribute to infrared absorption and emission so they can be removed from our numbers already.

[Turtle]

Originally Posted by Chris C

A few points--

turtle,

Global Warming by definition is just ΔT, not absolute T, so you need to look at drivers of climate change which can initiate a change from state 1 to state 2, and water vapor cannot do that.

Acknowledged; thanks Chris. The realclimate article concludes with this:

Originally Posted by realclimate

To be sure there are still some lingering uncertainties. Some recent data indicates that tropical upper tropopsheric water vapour does not quite keep up with constant relative humidity (Minschwaner and Dessler, 2004) (though they still found that the feedback was positive). Moist convection schemes in models are constantly being refined, and it's possible that newer schemes will change things . However, given the Pinatubo results, the models are probably getting the broader picture reasonably correct. ...

RealClimate » Water vapour: feedback or forcing?

The devil is always in the details. So if a single above water volcano can rock the boat so noticeably, I have to wonder how the underwater volcanoes roll it.

[freeztar]

Originally Posted by Turtle

I have to wonder how the underwater volcanoes roll it.

I'm sure we would all like to know.
Have you found any more info on this Turtle?

[Chris C]

There is more recent literature on specific humidity increases in the atmosphere, i.e.

Identification of human-induced changes in atmospheric moisture content -- Santer et al. 104 (39): 15248 -- Proceedings of the National Academy of Sciences

for a technical but much more thorough and satisfying overview of how water vapor influences climate, people should see this document:
(http)geosci.uchicago.edu/~rtp1/papers/CaltechWater.pdf

[Turtle]

Originally Posted by Chris C

There is more recent literature on specific humidity increases in the atmosphere, i.e.

Identification of human-induced changes in atmospheric moisture content -- Santer et al. 104 (39): 15248 -- Proceedings of the National Academy of Sciences

for a technical but much more thorough and satisfying overview of how water vapor influences climate, people should see this document:
(http)geosci.uchicago.edu/~rtp1/papers/CaltechWater.pdf

Roger. Here's that link 'til you get on the back nine. >> http://geosci.uchicago.edu/~rtp1/pap...ltechWater.pdf

Originally Posted by FreedzStar

I'm sure we would all like to know.
Have you found any more info on this Turtle?

Mostly I have found other forum debates. I did read one bit saying the Earth's heating of the ocean was 'normalized', or some such a matter of phrase, in their modeling using tritium(sp?) levels in ocean water? Sorry I didn't save that link. Maybe search that specifically next. Anyway, the point is of course a generalized value as an initial condition input makes for, IMHO, a less than confident view of the result of a model of a non-linear system.

[InfiniteNow]

Originally Posted by Turtle

Mostly I have found other forum debates.

What about a peer-reviewed publication?

[InfiniteNow]

I just found this site. It's a very good resource for anyone still befuddled by the differing thoughts and opinions on the matter.


Climate change: A guide for the perplexed - earth - 16 May 2007 - New Scientist Environment

Our planet's climate is anything but simple. All kinds of factors influence it, from massive events on the Sun to the growth of microscopic creatures in the oceans, and there are subtle interactions between many of these factors.

Yet despite all the complexities, a firm and ever-growing body of evidence points to a clear picture: the world is warming, this warming is due to human activity increasing levels of greenhouse gases in the atmosphere, and if emissions continue unabated the warming will too, with increasingly serious consequences.

Yes, there are still big uncertainties in some predictions, but these swing both ways. For example, the response of clouds could slow the warming or speed it up.

With so much at stake, it is right that climate science is subjected to the most intense scrutiny. What does not help is for the real issues to be muddied by discredited arguments or wild theories.

So for those who are not sure what to believe, here is our round-up of the 26 most common climate myths and misconceptions.

There is also a guide to assessing the evidence. In the articles we've included lots of links to primary research and major reports for those who want to follow through to the original sources.

[freeztar]

The AGU (with a membership of 50,000) issued it's formal stance on climate change, and guess what....

Human Impacts on Climate