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Two Thousand Years of Chinese Climate


MtnGoat

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Get your subscription and read up, folks. Line item 1 on alarmist news network "it's hotter than it's ever been"..... is a flat out lie.

 

http://www.agu.org/journals/gl/

 

Article:

Yang, B., Braeuning, A., Johnson, K.R. and Yafeng, S. 2002. General characteristics of temperature variation in China during the last two millennia. Geophysical Research Letters 29: 10.1029/2001GL014485.

 

What was done:

Using nine separate proxy climate records derived from peat, lake sediment, ice core, tree ring and other proxy sources, the authors compiled a single weighted temperature history for China spanning the past two thousand years.

 

What was learned

The composite temperature record revealed five distinct climate epochs: a warm stage from AD 0 to 240 (the tail-end of the Roman Warm Period), a cold interval between AD 240 and 800 (the Dark Ages Cold Period), a return to warm conditions from AD 800-1400 (which included the Medieval Warm Period between AD 800 and 1100), a cool interval between 1400 and 1820 (the Little Ice Age), and the current warm regime (the Modern Warm Period) that followed the increase in temperature that began in the early 1800s.

 

Another important finding of the study was the fact that the warmest temperatures of the past two millennia were observed during the second and third centuries AD.

 

What it means:

The results of this study demonstrate that the so-called unprecedented warmth of the 20th century is a myth.

 

Indeed, the warmth of this period was but a manifestation of naturally-induced regularly-recurring conditions similar to those experienced in prior millennia.

 

These results also serve as a testimony against those who would deny the existence of an extensive (hemispheric or global) Medieval Warm Period and Little Ice Age, as well as an extensive Roman Warm Period and Dark Ages Cold Period, as well as natural cyclical climate changes.

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Listen, Sammamish dude... global warming is one of those things that is pretty hard to prove one way or another. So what if we're slated for a warmer cycle during these centuries? Maybe we are contributing to this warmth, maybe we are not. Maybe the global warming is just what you are claiming, a temperature cycle of some kind. Maybe we contribute to the warmer temperatures on top of the cycle. Who knows?

 

I can't imagine that all the nasties we pump into the air simply "disappear" and cause no harm at all.

 

Nice article buddy. Phhhhhhhhhh........ [Roll Eyes][Roll Eyes]

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yup, here we go. I am currently perusing the IPCC report for sections on historical climate change and how they rule this climate history out of their proposed model for warming.

 

When I am done with that, I intend to go through it again, hopefully finding justifications for recent 20th century temps as a setpoint to measure "abnormal" warming against. You'll see a thread on that too!

 

regardless of how the IPCC and other anthrogenic warming proponents view this historical data, one fact remains...anyone who uses the claim that the earth is hotter now than it's ever been to buttress their warming claims, is simply wrong.

 

[ 09-25-2002, 04:08 PM: Message edited by: MtnGoat ]

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1) "global warming" does not mean every inch of planet earth is now warmer than it's been since pre-industrial times. just because china may have been warmer at some previous time does not mean the entire globe was. conversely, just because china cools the rest of the planet and/or the planet-wide average temperature can still be (and is) going up.

 

2) often left out of the discussion of "global warming" is the fact that we have not only been adding greenhouse gases to the atmosphere but also particulate matter (i.e. sulfur dioxide, which becomes sulfate particles, soot, dust, etc.). these particles scatter and absorb incoming sunlight, preventing some of it from reaching the surface of the earth. this has a cooling effect at the surface of the earth. climate models, field measurements and temperature records -- such as from China, in fact some of which I have made -- have shown that these particles have a significant effect on surface temperature. In places near and downwind of major particulate sources, most notably China and eastern europe (and before we cleaned things up a bit, the eastern U.S.) the cooling effect of these particles could fully or partially be offsetting the warming due to higher levels of greenhouse gases. because the particles only reside in the atmosphere for ~1 week their cooling influence only extends over a geographic area near the source region, not over the whole globe like greenhouse gases. thus having large regions that have cooled while the rest of the planet has warmed is fully consistent with our understanding of the climate and with current (IPCC) analyses of global warming.

 

3) a single study is not sufficient to prove or disprove whether we are screwing ourselves by dumping CO2 into the atmosphere. that's why the IPCC reaches conclusions based on a large suite of studies from both sides. their analysis includes studies such as this one.

 

4) keep trying.

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""global warming" does not mean every inch of planet earth is now warmer than it's been since pre-industrial times. just because china may have been warmer at some previous time does not mean the entire globe was."

 

True.

 

However, this data also verifies European and N American climate data for at least the previous 1000 years. Verification of previously extant warm and cool periods do not rest exclusivelt on Chinese data for this reason, but the Chinese data was interesting due to it's recent release and use of nine separate proxies.

 

conversely, just because china cools the rest of the planet and/or the planet-wide average temperature can still be (and is) going up.

 

"often left out of the discussion of "global warming" is the fact that we have not only been adding greenhouse gases to the atmosphere but also particulate matter (i.e. sulfur dioxide, which becomes sulfate particles, soot, dust, etc.)."

 

Very good point, I have not read up enough to dispute particulate data you present, and cannot claim to make any case concerning it.

 

"3) a single study is not sufficient to prove or disprove whether we are screwing ourselves by dumping CO2 into the atmosphere."

 

I do not claim it does. It does however throw claims made by some warming proponents into the proper light, that they are either lying, or have not done their homework.

 

It also raises the question, again, of just how the IPCC determines what a "natural" temperature rise is, what a "normal" climate should be, etc, since looking at the natural variations already known to exist, there simply is no static point.

 

"that's why the IPCC reaches conclusions based on a large suite of studies from both sides. their analysis includes studies such as this one."

 

That's why I'm reading it intently. Once I have finished the damned thing I will either join your side, or know precisely how to hammer on it.

 

"4) keep trying."

 

I intend to.

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"just because the earth has natural climate cycles (like anyone is denying that it does?!?!)"

 

then tell me how to figure what is "normal"?

 

" doesn't mean it's not possible for humans to cause climate change."

 

Surely true. It does however vastly complicate the burden of proof needed to claim we do.

 

You sure as heck better be able to explain why the earth's temps do what they do, including huge swings, before you try and posit you *know* they're doing something different. Especially when the timing of said swings indicate we are in a warming periond *anyway*.

 

Ambitious claims used as backing to impose huge and costly measures on billions of people better be provable or else you're pushing religion, not science.

 

And we haven't even scratched the real question, is spending trillions and compelling billions of people worth it to supposedly change the earths temp only 0.2C in 100 years? And delay the rise for 5 years? Even if implemented fully, and entirely correct, about warming and mechanisms, Kyoto gives us a pittance of difference.

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quote:

a single study is not sufficient to prove or disprove whether we are screwing ourselves by dumping CO2 into the atmosphere

quote:

I do not claim it does. It does however throw claims made by some warming proponents into the proper light that they are either lying, or have not done their homework


I guess I don't understand what claims it is you feel this study "throws into the proper light".

Many of the models that predict/show global warming due to anthropogenic greenhouse gases show cooling over China due to particulate (aerosol) cooling.

 

Regarding the question of how the IPCC decides what "natural" temperature is: I believe that the baseline was chosen for several reasons. it is a time period for which we have a lot of measurements/data so that the baseline climate system is well-understood. also, it is close enough to the present that changes seen between then and now are less likely due to very long time-scale climate cylces. for example, the change in temp over the past 50-100yrs due to the 20,000yr ice age cycle is miniscule.

The issue is not whether we're going to make earth hotter than it's ever been before, but whether we are going to change the climate 1) so rapidly that ecosystems and human institutions (i.e. such as where we grow crops, etc) don't have time to adapt and 2) to a state where the earth can no longer support 6+ billion people.

Also, the changes between now and the baseline period *are* compared in magnitude to changes between now and an ice age and between other types of climate cycles. It's not as though the IPCC only looks at temp records over the most recent 100 yrs.... And the changes we are talking about long-term are on the same scale as the changes between the last (full) ice age and pre-industrial temps. Not insignificant.

 

As to whether or not we should spend billions of dollars to fix the problem: There are many studies showing that we could transition off of fossil fuels in a way that would be a net *benefit* to the economy. Sounds to me like you've only read the ones that say we'd all go to hell in a handbasket if we tried to improve the car avg fleet efficiency by 5mpg. Try looking into some of the stuff put out by the Rocky Mtn Institute.

 

FYI I would not argue that we should take everyones' car keys away tomorrow. But there are many things that the gov't could be doing and that it is not because it is so wrapped up in the old-boy-fossil-fuel network. Many of these things would have ancillary benefits, such as the obvious decrease in our dependency on foreign oil and a decrease in pollution. I don't mean to sound like a flaming liberal reactionary but ya know there are kids dying even in this country from pollution every day...and in places like china, which could built their economies on renewable rather than coal power if economically viable alternative energy sources were available, entire villages' normal mode of death right now is from lovely things like arsenic and flourine poisoning that they get from burning coal. don't know if you've ever seen that but it's pretty frightening. death by massive body-sore infection. personally i think it'd be really smart if the U.S. got ahead of the curve and developed stand-along power sources so that we are ready to sell them as developing countries' economies grow. but as usual the germans and japanese are ahead of us on this one.

Ah but I digress. This whole economics thing is both beyond my scope of expertise and, more to the point, a discussion that I do not have time right now to persue...

 

Glad to see you are working so hard to understand the problem. I'd prefer a well-educated skeptic over a reflexive jump-on-the-bandwagon chicken little any day.

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"I guess I don't understand what claims it is you feel this study "throws into the proper light"."

 

I should have clarified, my bad. The specific claim in this case is one I see constantly repeated, the "hotter than ever" claim.

 

Yes, it's only one pillar of a diverse argument, often made by people parroting what they've read for warming, as much as others parrot their attacks on warming..... but it's a false one and it's proper rejection moves us closer to a true evaluation of the problem at hand. Proponents of anthro warming would do well to correct well meaning but misinformed folks on their side about this because misinformation serves no one well, regardless of good intent.

 

You have other good comments I'd like to address later, and I will do so when I have a couple more minutes. It's certainly a pleasure to argue points with an opponent who can do so with courtesy.

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It's just these long assed, boring arguments. What are you guys trying to prove anyway -- who's the bigger bullshit artist. Nobody reads 6 paragraphs of textbook theory. How about 1 paragraph to make your point.

 

Ah the hell with it. Do what ya want. [big Drink]

 

[ 09-25-2002, 05:45 PM: Message edited by: trask ]

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