[Mtn Dog]

RodF - I'm not real sure what you are asking but please let me clarify if I can. The Energy Balance Equation is nothing more than a formula to match the colored chart I provided earlier in this thread. You didn't have any questions then, so just what are you asking now and why? We're not talking about Venus, we're talking about climate change on earth; so stop trying to change the subject. The volatility suggestion is in the fact that the different elements in the equation are multipliers. But this is tempered by the fact that earth's temperature has remained relatively constant in spite of far greater changes to the other factors throughout its long history (e.g.: changes to CO2 concentration and earth's reflectivity through glacial advances). The relevance of the energy balance equation is not in putting specific numbers to the variables; it's in recognizing that the amount of energy the earth receives is in equilibrium with the energy it reemits. Reread my posts, I never said it was all you need to know, I said it was all you need. In other words, the global warming debate is framed by this equilibrium and any potential changes to it. Any computer modeling or other attempts to show future increases in temperature must be balanced by equivalent changes in this equation. So to have the global average temp. rise on a level suggested by the latest assessment report would require earth's ability to dissipate heat to drop by the same proportion to the fourth root.

[RodF]

MtnDog, you've made grandiose in this thread about the significance of this equation in the context of a discussion of the greenhouse effect. I don't understand those claims. Do you understand the physical assumptions inherent in this simple equation? If so, list them. Key question: what is the difference between Te, the effective temperature in this equation, and the actual measured temperature? Again, numbers might be helpful.

[Mtn Dog]

RodF: The point of bringing in Earth's energy budget and the energy balance equation to the discussion is that it helps "frame" or limit the grandiose claims of AGW. It shows how any changes to the earth/atmosphere system affect other elements in the system. So when the assessment reports state that there is a likelihood that temps could rise 6-10°C under the right scenario you can see that in order for that to happen then earth's reflectivity and/or dissipation of heat must change rather drastically (assuming solar radiance stays constant). And in order for that to happen we would have to change the concentration of the trace greenhouse gases radically (far more than doubling CO2, which will only change temps by about 1°C). The equation is theoretical and assumes that the earth is a single point of constant temperature as one spherical, radiative body when actual measured temps are averaged across the globe in the hopes of getting something representative and comprehensive. This has been a concern in the past but with newer, more accurate equipment I think scientists are now getting a handle on the reliability of their temperature data and are able to 'fill in the blanks' better than before. It is interesting, nonetheless, to compare actual temps to proxy data for the last 100 years and see how small the discrepancy is.

[Scrooge]

Mtn Dog, your "theoretical" equation is meaningless, as is your 4W/m2 mantra. What we have to do is explain things like .......

........ the 1.2 million square km reduction in Arctic sea ice. Not try to prove they're impossible. In fact, your equations can't tell us any more about the limits of what global warming may bring than they can explain what's already happened.

[Mtn Dog]

Scrooge: No one I know disagrees with the fact that the earth is getting warmer. The question was never whether Global Warming is or is not happening, it was whether the warming we are experiencing is caused at least in part by human activity and if so, to what extent. Science can explain what has already happened and regardless of Global Warming being anthropogenic or natural, humans are obligated to adapt the changes it brings (some will be positive and other changes will be negative). The 4 W/m2 is the quantity by which a doubling of pre-industrial CO2 levels will increase the Greenhouse Effect. But there are other natural and human causes that can change earth's temperature as well. You've made a correlation between rising CO2 and rising temperature as if one is automatically causing the other. All I'm asking is for you to tell this story with numbers. How does CO2 cause a rise in temperature and by what amount for a given change in concentration? I've already done most of the homework for you. As for the Arctic Sea Ice it's my impression that this last winter restored the ice back to somewhat typical winter levels. The only reason it was even newsworthy is because the area of the usual summer season melting was quite extensive in 2007.

[RodF]

MtnDog, it appears from your reply that you no idea what physical assumptions are made in deriving the simple equation* you posted:

[pimaCanyon]

Here's an article that discusses why we can't take atmospheric temp readings, even over the course of year, to mean a whole lot. We need to either take a very long term view of what's happening to atmospheric temps--like over many decades--or we need to start taking temperature measurements of all the earth's bodies of water at different depths AND temps of the crust. We don't have that data going back hundreds of years like we do for the atmosphere, so even if we were to start taking those measurements today, we would not have the historical record we'd need to determine the direction of a trend (if any). The article discusses the current La Nina and its effect on atmospheric temps. It's obvious that we don't have enough data on oceanic temps and that's why we will just have to wait a few decades to see how the AGW things plays out. http://news.bbc.co.uk/2/hi/science/nature/7329799.stm

[Mtn Dog]

Larch: Thanks for posting that link. I was going to post it myself. WaMtnGal can check it out for a better description of the effects of La Nina this past season. I know the warming trend relies on more than one year of data but it is interesting to see how drastically El Nino and La Nina affect earth's climate and both are natural phenomena. It's also interesting to see how a La Nina event can practically erase what was projected to be a 10 year warming trend (1998 to 2007).

[wamtngal]

I am still in awe of La Nina and El Nino and how they affect our climate. I read somewhere that when there is a very intense La Nina, it can bring about an El Nino (I think this was on the wikipedia page for La Nina). Wonder if that will happen this time.

[RodF]

[Conrad]

It seems I've seen repeated claims that Mtn Dog's assertions show a lack of the knowledge from any "basic climatology textbook". Would anyone like to recommend any specific climatology textbook(s) which would demonstrate this? It would be interesting to see if/how Mtn Dog is contradicting basic conventional climatology.

[Mtn Dog]

Yeah, Conrad, I'd like to see that too. RodF never responded to my point on pages 20 and 21 of this thread. In fact, it was the links in his posts then that confirmed the heating that would result from doubling CO2 that I had also been saying. The energy balance equation reflects the fact that the earth/atmosphere is not a perfect absorber of ultraviolet energy from the sun (Alpha) and also not a perfect emitter of infrared energy back to space (Epsilon). RodF is speaking of energy balance for a perfect black body, which the earth clearly is not. I'm not going to get into who is or isn't smart enough about this to know where the disagreement remains. Everyone can figure this out for themselves if they read enough and learn about what is, and isn't going into the climate modeling. But RodF, you're not making any sense now. How are scientific equations OK for high schoolers but somehow inaccurate for higher level science? It seems you're trying to advance an argument through complicated jargon with the hopes of appearing as if you actually know what you're talking about but again, just like page 21, you've failed to answer the questions I've asked and also failed to rebut the facts I've presented.

[Scrooge]

Mtn Dog tells it like it is.

..... CLUB .....

[RodF]

[Mtn Dog]

RodF - The Wikipedia link you posted explains it all: