Splat

Folks, the global warming debate has pretty much stopped being a debate. Heat island effects and other critiques--many/most of them perfectly valid, regardless who paid for the research--have been duly considered and folded into the current understanding (the heat island issue was raised by Robert Balling, and the climate community took it seriously enough to re-analyze the station data and to compare trends for land stations and ship-based measurements; not surprisingly, the temperature averages decreased, but they didn't decrease by much.) Reams of paleoclimate data have been gathered and analyzed in the past decade, computer models (though still imperfect) have improved dramatically, and it all points to the same conclusion. It's warmer, and we're why.

Even the Bush administration (remember the two oil executives in charge--rabid environmentalists that they are) has accepted the evidence for warming as valid and that human actions are the primary cause. They've given up trying to discredit the science. They've just decided they're not going to do anything about it.

As Yeti pointed out, it really comes down to economics, not climatology, and Bush et al. deserve credit for cutting through the piles of BS that have obscured the issues and putting the debate where it should be.

All societies adapt to their environments, and when environments change, people have three options: move, adapt, or die. It doesn't really matter whether we talk about warming or cooling, wetting or drying; the important thing is the rate and magnitude of the change, not the sign. What constitutes a critical magnitude depends entirely on the economic structure of the society, its technology, culture, etc.

In the past, societies have fallen apart when the rate and magnitude of climate change exceeded their capacities to adapt or move. But those are probably poor models for what might happen in the future simply because so much is so different now. We have vastly more powerful technology and more flexible economies, which suggests that we should be better buffered against climate change. But at the same time, the stakes are much higher simply because there are 6 billion of us now, and most of us rely on somebody else to grow our food.

Climates are changing, and the main reason they're changing is that we've altered the composition of the atmosphere. The more we continue to alter the composition of the atmosphere, the more it's going to change in response. That's simply physics. The really interesting questions have to do with how we can adapt, and who should pay.

As Alaska warms, its permafrost is melting, buildings are sinking and falling down, highways are buckling and cracking, forests are dying...should I care? Should I help pay Alaskans to re-engineer their infrastructure? Is it worth it?

No answers, but good stuff to chew on.

[Demon-sword: the graph represents either global or northern hemisphere averages (no source, but I'm pretty sure it's the NH curve). Regional fluctuations get washed out, though events like the Little Ice Age _are_ reflected in the graph: Dickens' frozen Thymes was part of the long cool spell (temps around -0.2 C lower than average) from about 550 BP to about 1900 CE.]

theyeti

You are referring to the <a href="http://www.ngdc.noaa.gov/paleo/globalwarming/medieval.html" target="_blank">"Medieval Warm Period"</a> and "Little Ice Age" respectively. As before, the Medieval Warm Period was not global in scale -- it only affected northern Europe. By contrast, the current rise in temperature is global in scale. The "Little Ice Age" was a real global event. If you look back at that chart between 500 and 600 years ago (ca. 1400-1500 AD) you'll notice a sharp downward spike. Here's another chart where you can see it:



The Little Ice Age is thought to have been caused by some serious volcanic activity around that time. Right now, we are experiencing higher than average volcanic activity, and things are still getting hotter. What does that tell you?
Because these are average, global temperatures. The whole world isn't suddenly turing into a steamy jungle. But the fact does remain that the northern lattitudes are heating up at an accelerated rate.
Read all about it <a href="http://www.brighton73.freeserve.co.uk/gw/temperature.htm#urbanheatislands" target="_blank">here</a>

Briefly:
<ol type="1">[*] Most monitors are located in rural areas, not urban areas.[*] Climatologists correct the urban measurements against the rural ones.[*] The difference is not very significant anyway because...[*] The amount of heat trapped by urban areas has not changed much since measurements were first taken, and in many cases has gone down due to lower population density and higher energy efficiency. [/list=a]
This is a <a href="http://www.brighton73.freeserve.co.uk/gw/temperature.htm#satellitetemperatures" target="_blank">separate issue</a> (and one that the GWDs have spread a lot of disinformation on). Early atmospheric measurements taken by sattelite seemed to show a cooling trend in the atmosphere. But this was caused by orbital decay of the sattelites -- when the measurements were corrected, there is a slight warming trend. The troposphere is warming half the rate of the surface, but not quite as fast as predicted by some models. The Stratosphere, meanwhile, is slightly cooling. Why? Partially it's a consequence of greenhouse gases, which trap heat closer to the surface. Also, it's caused by the recent spate of volcanic activity and the depletion of ozone.
I brought up mention of those for two reasons:
<ol type="1">[*] Both of them were probably caused directly by a massive release of CO2, which itself was caused by either a meteor or oceanic upwelling. [*] They demonstrate clearly what happens when there is sudden, dramatic shift in climate (i.e. mass extinction). [/list=a]

However, you are correct in that what we should focus on is the last 6000-8000 years give or take. The fact remains that the current warming trend is unprecedented, and it will continue to accelerate. And unlike past trends which were less acute, this one cannot be explained merely by natural fluctuations like solar output and volcanic activity.

theyeti

theyeti

I would take anything Bjørn Lomborg says with a large grain of salt. There was a thread awhile ago (can't find it now) where someone linked to his claims about Kyoto. I read his claims and checked on his sources....and found that he butchered them pretty good. He drew out numbers that suited his purpose and ignored those that didn't. He would cobble together numbers from difference sources that used different assumptions. He used the high estimate when useful for one thing and the low estimate for another. Some of his numbers seemed to come from thin air, and were flatly contradicted by his sources.

Actually, I can see nothing there that looks "poisonous" or "emotionally laden" to. That link doesn't have much comentary at all -- it just contains more links to individual subjects. The one on <a href="http://www.gristmagazine.com/books/schneider121201.asp" target="_blank">climate change</a> looks pretty spot-on to me, and clearly demonstrates what an artful obfuscator Lomborg is. The thrashing he gets is severe, but it's not emotive. I haven't checked the other issues (e.g. population and human health) so I can't comment on those.

theyeti

echidna

Maybe I was unlucky but the first critique I opened was this one …

I feel their cutesy caricature cartoons would have been better replaced with data graphs.

echidna

When I was completing schooling in the late 70’s - early 80’s, the environmental theme we were taught was about the looming shortage of resources (oil being the most prominent of course), that we were bleeding the planet dry and that the early third millennium would show a global collapse from lack of resources. Not only oil, but metals, rare compounds, you name it. And the scientific evidence was just as strong and damning as today. An extremely pessimistic outlook to be feeding impressionable kids. Only the “ignorant” economists (like my very unscientific political lecturer father) were sceptical back then.

2 decades later and the ignorant economists were right, the scientific thinking has been soundly rebuked, but replaced with another scientific environmental doomsday scenario. Forgive my scepticism.

Note that SciAm’s critique of Lomborg even cites material from Paul Erhlich who was one of the leading doomsdays we studied back then. His catastrophic predictions from the 80’s have proved empty, and yet SciAm still calls him as a credible witness.

Nic Tamzek

Oooh, my first off-evo/creo post here.

Several questions should be distinguished:

1) Is the earth warming up?
2) Are humans the primary cause?
3) Are the effects significant?
4) What should we do about it?

MHO is that #1 is indisputable, #2 is very likely, #3 is much more disputable (like was said, a matter of impacts, most of them difficult to predict except perhaps sea-level rise issues), and #4...

On #4 the thing is that there are an awful lot of "no regrets" actions that can be taken. There are lots of reasons to reduce fossil fuel reliance; there are a lot of chemicals besides CO2 that contribute to global warming (a CF4 molecule is, I believe, thousands of times more potent than a CO2 molecule, because (a) it absorbs longwave radiation of a different wavelength than CO2 and (b) it persists much much longer in the atmosphere).

So there's MHO.

Nic Tamzek

Oh yeah, Lomborg is dumb.

nic

echidna

(slaps wrist) Note to self : don't post when you're in a shitty mood.

[ September 19, 2002: Message edited by: echidna ]</p>

The Lone Ranger

This graph, showing the relationship between atmospheric carbon dioxide and methane levels, and temperature in Antarctica during the past 400,000 years or so might be of interest.



Cheers,

Michael

[ September 20, 2002: Message edited by: The Lone Ranger ]</p>

Ruy Lopez

Lone Ranger:
Your beautiful chart seems to be saying that CO2, Methane levels and the ICE AGES are correlated. Also that ice ages when they end, they do so very abruptly as compared to their build-up. Now, why the hell should Co2 and methane levels rise gradually for about 100,000 years and the go into abrupt freefall in 5,000 to 10,000 years and repeat the cycle every 110,000 years?

This phenomenon seems beyond human ability to interfere with CO2 and Methane. All we did, if any, was to increase a bit more Co2 and methane levels over their usual cyclical highs every 110,000 years. Explanations, Lone Ranger? Yeti? I have none.