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Old 15th-August-2007, 06:26 AM
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Quote:
Originally Posted by Windguy
Yes the magical mystery methane monster living in permafrost is going to bite you on your backside. Yes and the great fairies of sea level rising is going to lower the albedo effect. What I've stated is a possible future that is still a future that GW is more and more likely to cause.

K&T and your model is not what I'm arguing about. But to get your figure of 1.2W/m^2 GHG forcings? As in cutting off sixty percent of the real forcing number, you would have to half the total effect of GHG's in the atmosphere just to get that number. And if you did that, you would see 10 degrees celcius during the day and -10 at night on a hot 40 degree celcius summer day! ain't happening once again. unless the clouds were solid mirrors and 100% infrared absorbers hey!

Once again, you state a million and one natural causes for the current heating, then you also state termites are at least fifty percent of the methane levels or greater. Hasn't methane levels increased 150% since 1750? If it's termites, then it has to be man that has changed the landscape for them to thrive so well. An incredibly basic assumption for which a scientist (that you wouldn't believe anyway) didn't need to to tell me.

The GW crowd has far more reliable evidence GHG's than any other form of forcing out there, so either believe in that evidence or believe in the magical mystery forcings that you believe is the current reason for temperature increase, Oh NASA got it wrong! that's right it only happens in America.
Your examples require some sort of significant warming to be caused by ghgs to unleash the permafrost methane. That is unless they've been releasing all along anyway. What you present is fairy tales, not science. It's no different from me giving the scenario of a giant asteroid coming out of the sun's direction without warning and splattering earth with greater damage than what happened 65 million years ago - and it happens aug 22, 2007. It's not an impossible scenario and is likely to happen in the next few million years, but it's a virtual certainty it's not going to happen on the 22nd, even though it's just as likely to happen on the 22 as on the 23rd or on whatever ever day it's going to happen on, sometime between now and a few million years.

It's true the earth has gotten warmer than now and it's true the earth has been colder than now. And, there's no accurate data on just how fast those events happened. I seem to recall some mostly intact mastedon they dug up in siberia that evidently froze to death after munching on fresh grass and flowers - sounds rather fast offhand. What's more, all this stuff happened without any assistance from man. We've just got out of a mini iceage around the time of the industrial revolution and there's evidence of solar variation not seen since that time.

As for the number of 1.2 or so, that is not a reduction in ghgs, but rather a reduction in the perceived effect simply because there is a great deal of blocking of radiated energy from the surface already due to the clouds.

It's simply that there is a difference between clear sky and cloudy sky dynamics.

As for the termites, coming out of an ice age, one is going to experience lots of growth among species. If things are getting warmer, you're going to see more activity. If things are getting colder, you'd probably see less activity. It's obvious from many examples that nature doesn't necessarily maintain perfect balances and optimum values of species. Long before man started an industrial revolution, they were subject to massive breakouts of locust plagues.

Mirrors aretypically good for around 92-96% reflectivity. My model chose 0.8 (or 80%) as that is well within the numbers give for clouds. What's more, when calculated with ghg absorption of incoming energy, the albedo (as measured at the TOA) came out to be 46%, just below what the cloud albedo is thought to be as viewed from space (~50%).

The numbers I used are not chosen to give an intended outcome but merely to reflect a reasonable value for something not well known. And it works out quite well. As for the 1.2W/m^2, that is a conceptual interpretation and it's a different way at looking at and understanding something. As long as the circumstances don't change, it's not incorrect. It's not how it is considered by most because it will become incorrect as cloud cover changes.

However, your 2.5 value is based upon a particular mean surface temperature and at a particular surface emissivity and it is a clear sky value, not a mixed sky value. Actually, I think the number is calculated using emissivity = 1 and the temperature = 287 or 288 K.

I'm not sure where you got your 10C numbers from, but they don't come from a correct energy balance analysis or even anything close.

Just to toss in a couple of other fun tidbits of unusual results, it seems that clear sky influx of power to the surface decreases by about 0.4W/m^2 at the arctic circle and about 0.8W/m^2 at the equator. That means there is more absorption in the atmosphere (generally upper atmosphere, not lower) and less energy to radiate or dissipate from the surface. Note those values are for clear sky and are the difference between now and a doubling of today's ghg levels.


As for the 1001 other factors I keep mentioning, they just some of the other factors that also affect the temperatures. It doesn't matter if ghgs might be most important with 10 times the effect of any other when there's hundreds or thousands of smaller factors that can add up to far more. when this malarky started, it was all co2's fault, until they discovered that methane was good for 30%.

BTW, those numbers are even based upon segmented by latitude rather than averaged over the globe and it's using actual emssivity as a function of wavelength for coarse snow and for liquid water. It was interesting to note that the albedo as measured from the toa runs around 1% for ice and water and around 40% for some snows.
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