http://science.nasa.gov/science-news/science-at-nasa/2010/13dec_globaleruption/
There’s something in Classical Studies about climate change—remember, we’re the guys [in my old academic field] that deal with the oldest written accounts and oldest civilized remains in the world. And somebody noted something interesting back before the 1970’s…
The rhythm of civilization is on a 500 year cycle. Every 500 years, the barbarians ride out of the steppes and trash the farmers in the Tigris-Euphrates; dynasties fall; famine hits the Tarim Basin; the Gauls (later in history) invade Rome (then move on to Asia Minor). Ie, every 500 years, the apple cart upsets and things rattle for a while.
Some enterprising folk have wondered if our Sol is a periodic star, with a 500 year cycle. So I always told my history students to look out for the year 2000, that there might be climate glitches, famines (crop failure), or weather upheaval. What went on in history was a drought in the Tarim, forcing horse-using barbarians to move on, which nudged the next guys over, and they nudged the next: it was dominos, all along the trade routes and migration routes. People who’d matured into a power would try to go south to get food around the Med (or north, from Africa) and weaker civilizations would go down. When Rome ruled, they did what any selfrespecting global civilization would do, and used their ships to move grain from regions of plenty to regions of famine and kept civilization together in that one; but come 500 AD, they blew it, got caught in a period of disorganization; 1000 AD, give or take a century, you’ve got the Vikings and the Normans, not to mention chaos in Asia; 1500—heck, explorers were out in ships, and TRADE was big because there were areas where they really wanted goods like food…etc.
Just some food for thought.
I think that you are oversimplifying. Yes, there is evidence of the 500 year cycle, but at the same time humans have damaged the ecosystem, and there are other things going on as well (another theory I heard was of a 2000 year cycle which was off the 500 year cycle by about 100 years).
A while back some archaeologists in the U.S. were able to track the migration of an Indian tribe by the die off in coastal shell fish (this was something B.C., don’t remember the exact date). The thing is that pre-modern were capable of damaging the ecosystem, either by purpose, or by accident (temperature drop as reforestation took place after the Black Death nearly wiped out Europe).
So yes, I agree there is a 500 year cycle, but there’s other things going on too, which could make the 500 year cycle skip a round, or possibly be twice as hard.
Wayne
I have to oversimplify, to get it into a paragraph or two 😉 —but yes, and always to be considered is the fact that, via archaeology, you are looking down a well at a one-acre or less sample: a situation beyond ‘local’, and somewhat microfocussed. You sink a lot of wells, and your ability to connect your dots consequently gets better, but it’s still a big planet and a lot of microsystems which may be affected by geology as well as any possible sun-cycles in addition to local effects of population. Tree rings give us a lot: love trees. But the opening and closing of routes like, say, a land bridge, the global effects some notable eruptions (the ice sheet dust record is only good for about 12,000 years) and lately we have mapped old coral shelf patterns off Australia indicating prior ocean levels going back before that—very definitely a patchwork of wells, but our connecting the dots is improving.
I don’t know if it fits into your time-line cycle, but the period around 1250AD was a climatic period both historically and meteorlogically for me.
I think there was a massive drought and some other ecological events going on.
In North America, the Anasazi culture dissipates. Leaving behind cliff-dwellings and signs of cannibalism. In Cahokia, the largest known city occupation, the population goes way down and the social structure faces major political change and upheaval eventually collapsing completely leaving the city abandoned. Some of this had to do with the lack of available firewood for miles around.
In Europe, it is the heart of the “Dark Ages” with rampant feudalism, wars, plagues, and famine.
In the Near East, Roman culture finally falls. Yes Roman, most historians seem to overlook the Eastern Empire and Constantinople.
In the Far East, normally small nomadic tribes are banding together to grab more resources than ever before eventually turning towards Europe.
Though I’m greatly oversimplifying for the sake of brevity, something big was happening on a global scale, and I believe it was environmental. To whether it had anything to do with solar cycles, no clue, but it does show how a period of bad climate can effect things worldwide.
Sorry to quibble, but…
In Europe, it is the heart of the “Dark Ages” with rampant feudalism, wars, plagues, and famine.
So how was 1250 significantly different in climate and history from 1150 or 1350?
In the Near East, Roman culture finally falls.
I thought that Constantinople finally fell to the Ottomans in 1453.
In the Far East, normally small nomadic tribes are banding together to grab more resources than ever before eventually turning towards Europe.
Which tribes would those be – Turks? Central Asia is not the Far East.
oh lots of quibbling ! first time I have heard that theory of reforestation/climate change after the black death – got any references about that – very interesting if so …. in England we tended to have lots of sheep instead of lots of arable, no reforestation.
um black death dates – it peaked in Europe between 1348 and 1350. just before it in England there was a generation of famine – overpopulation. nicely cured by the black death. doesn’t fit to 1250, when we were doing very nicely here, thanks very much …
“So how was 1250 significantly different in climate and history from 1150 or 1350?”
It is near the middle of a period of very dry summers and long winters causing several famine as chronicled in the monastic almanacs of that time.
“I thought that Constantinople finally fell to the Ottomans in 1453.”
December 13 2015 – Frederick II, Holy Roman Emperor, dies, beginning a 23-year-long interregnum known as the Great Interregnum. Frederick II is the last Holy Roman Emperor of the Hohenstaufen dynasty, the last to have direct lineage and links to ancient Rome.
“In the Far East, normally small nomadic tribes are banding together to grab more resources than ever before eventually turning towards Europe.”
I was referring to Möngke Khan, who conquered Iraq and Syria as well as the Tai kingdom of Nanzhao. He absorbed many smaller, now nameless, tribes before conducting these campaigns. Theoretically, there was a domino effect, pushing other tribes west for better raiding and pasture resources.
Sheesh, so much for brevity… I really didn’t want to go into excruciating detail, just though there were allot of interesting coincidences that may be linked to climate around 1250. Free thinking isn’t a crime, but apparently it is a punishable offense.
Frederick II was a Holy Roman Emperor who died in 1250, but as someone once pointed out, the Holy Roman Emperors were neither holy, nor Roman, nor emperors. 🙂
He certainly had no direct link whatsoever to the ancient Roman emperors, and no connection at all with Constantinople.
The Turks were well established in Anatolia by the 11th century. They were certainly not pushed there by the Mongols.
As someone else once said, we are all entitled to our own opinions and theories… but not to our own facts.
😉
Correction: Though Fredrick the second was important to the period. As far as Constantinople is concerned, I was thinking of Baldric II the last Latin ruler of the Eastern Empire. Both figure in to the long, long, debate to when the Roman Empire actually fell. Which I’m not going to even try to defend either way.
Umm… there was no such ruler as Balderic II… I guess you meant someone else…
You are talking about this universe aren’t you, not an alternate one? 🙄
Baldwin II. http://en.wikipedia.org/wiki/Baldwin_II_of_Constantinople Relative of mine. 😆 —as yet unproven.
My apologies, Baldwin II. If your command of history was so great you would have realized my error and kindly corrected me.
But apparently you take greater pleasure in being a frivolous pedantic quibbler. One who fan the flames of his ego by belittling others, whilst completely missing the original point of the statement.
Sorry C.J. I’m done…
Sorry, CJ, Balwin it is. ✔
But he was king of a Crusader state established after the Crusaders captured Constantinople, and which lasted for 50 or so years. He was descended from the count of Flanders and Hainaut. The ‘Latin’ in the name of their ‘Empire’ just means ‘not-Greek’. There is no actual connection with the Roman Empire, and of course they spoke some dialect of French.
The Wikipedia article says, “The extremity of his financial straits reduced him soon afterwards to handing over his only son, Philip, to Venetian merchants as a pledge for loans of money.”
I guess when you are reduced to pawning your only son, then things are really bad! 🙁
Oh it has to be environmental. You get the Great Drought in the southwest in the late 1200’s and huge abandonement of cultures with the Anasazi breaking up into the modern pueblos and Hopi, Hohokam breaks up with oral traditions amounting to peasant revolts [modern Pima and Tohono O’dom] and the Hopewell crash, while Europe is in the beginning stages of the Little Ice Age which will go on for about 550 years. We’re in a warming cycle that’s about 150 years old and just now learning enough to ask hard questions about natural sciences, but we don’t know enough about the systems to really understand how much impacts we have on them — I’m talking global warming, which no matter how you personally feel about it, it’s not very well supposed by the archaeological evidence; this sort of thing has happened before and as dramatically without any influence by modern industrialization. Regardless, folk have definitely managed to screw up their immediate environment in more than one instance from such things as deforestation with resulting drastic erosion, over salienating the soil by lousing engineered irrigation systems, or doing some other stupid thing. The biggest problem is all that was happening when you had substantially less than 1 billion people on the planet and you could concievablly trundle on to the next valley if you could shove your way in. I think we need to start putting serious efforts into FTL development. Or paying way more attention to archaeology to figure out what responses just flat don’t work under different environmental conditions.
Sorry — soap box button got pushed. Good primer question, CJ!
Without interference from modern industrialization, we were as a species doing some major alterations, doing slash-and-burn agriculture, taking out forest, with the associated impact on climate aside from just the smoke: everybody on the planet was cooking with wood, charcoal, or dung, and the air over some heavily populated areas was not pristine. Probably the whole city of ancient Rome couldn’t compete with a dirty set of smokestacks in Eastern Europe, where snow fell black, in the 1990’s—but what happened as a result of massive woodcutting was considerable, and continual. A pall of smoke hung over every human gathering, winter and summer, and thickened during cooking hours, or cold snaps. As population increased, Europe lost a lot of its forests. Charcoal industry arose, preburning wood to make its transport easier. The isles up by Scotland used to be wooded, but the building of ships and the feeding of boilers after the age of sail I’m told just stripped them bare—there are reforestation efforts going on there. The few surviving ‘big’ timbers to be had in Norway now, when they used to be used in building, are now in museums. You can almost tell where American colonization had gotten to when they turned to coal and discovered petroleum: it was dirty, but it DID stop the felling of old-growth forest, until they started building Seattle and San Francisco: Seattle was founded on the timber industry, supplying California and then Alaska with cut wood shipped in wooden ships to build wooden cities. Honestly, except for the automobile, I think we were possibly more destructive of the environment BEFORE the machine age than after. I look on the petro-industry as what stopped a total deforestation. And if it’s gotten us to the point where we can switch to cleaner means, we may have, by blind dumb luck, have dodged a climatological bullet.
there were scottish islands covered in hazel trees which lost them due to very early depredations – hunter gatherers, I think. and the wash got filled in with alluvium they think due to bronze age deforestation ..
Weather data for 1250-1300AD
http://www.longrangeweather.com/1250ad.htm
Well, and we left out the Little Ice Age: we know so much about that one because we were writing and keeping records. It was, however, significant to the American and British armies in the Revolutionary War, to villages that starved, people that froze to death, and to the settlers in Greenland. Yet it left very little in the way of ‘scars’ that might be glaringly apparent to researchers a few centuries on. Easy to miss minor fluctuations, until a civilization is vulnerable and goes down at the same time. It’s that digging pits and connecting the dots thing. We know the Med has fluctuated in level or there’s been geologic change: we’ve got sunken ports in the Med to prove it.
One interesting bit: the planet’s temperature balance is resistent: so if you have cold and misery descending on Europe, the Middle East may get a bumper crop of produce. Rome survived some serious problems around BC/AD by shipping grain out of Egypt. So far as I know we haven’t gotten a good climatological record for that particular period, though it just may be so confused —or detailed—that we haven’t sorted it out entirely. We know that people weren’t starving in the Empire, but there was a lot of barbarian unrest hither and yon…and I’m sure that data must be out there, by now, but I haven’t heard anybody putting it out as Weather of the Empire…so I can’t tell you, just that there was a problem, and there was ‘barbarian unrest’ and a lot of movement. My tolerably educated guess is that there was a problem, but that it was relatively mild compared to other bumps.
The solar event photographed above tells us our star has a lot of surprises: this is probably something that a star does periodically—or even for long stretches of time—that might affect its output. But we’ve been taking precise views of this star only for a few decades; and we’ve been keeping fairly good records of its activity only for a century or thereabouts. So we don’t know beans about what’s normal or not-normal.
Just because it’s a hot political topic, but I think being handled in a silly way, don’t expect me to take either extreme side’s total view. My position is we flat don’t know enough about the cycles and the triggers to deliver an absolute answer or solution—but this is the only planet we’ve got that’s habitable. So we need to stop throwing crud into the atmosphere, we need to behave far better environmentally. And we need to know more before we can present a tightly-evidenced ‘proof’ to either side of how much, how far, and what we’ve done. We’re trying to learn. We’ve got some data on the rise of the machine age that’s indicating we’re interfering with what’s been fairly regular cycles, likely hastening a warming trend that’s been going on for 12,000 years. And we know that the planet has some corrective mechanisms (the thermohaline conveyor current has been in operation since the continents assumed their current configuration) that we’d really rather not trigger. So it’s not a red and blue issue, nor a black and white one. We theorize that when we hit the tipping-point, the Earth will take care of its problem, but have we learned enough to hold it back from tipping? We kind of know how: interfere with the Conveyor. But what happens if we hold it back artificially and let the heat-debt—call it global warming or whatever—go on building up? I think we’d get a deeper, nastier Ice Age, but no one’s quite sure. Can we moderate the heat WITHOUT shutting down the Conveyor? The Little Ice Age hints there is a halfway-ice-age possible. But what did happen to the Conveyor when that happened? Who’s got the international consensus to try to bring down a bitsy one repeatedly until we could even things out?
http://en.wikipedia.org/wiki/Shutdown_of_thermohaline_circulation
And it’s not a neat loop with a spigot like a garden hose. And there are events like warm periods and the Younger Dryas, etc, times of fluctuation for reasons we don’t entirely understand—in this case we’re living at the bottom of one of those archaeological digs ourselves, looking up from the well and trying to figure out what the whole system is like.
I love planetary weather: there are whole books on it. And you’d figure Earth would have one heckuva complex system.
as to the Conveyor – interesting link on that wiki page saying that it’s not the gulf stream that is responsible for our mild climate here – that’s a kind of urban myth left over from science done in 1855 – “Because sea-surface temperatures vary less through the seasonal cycle than do land-surface temperatures, any place where the wind blows from off the ocean will have relatively mild winters and cool summers. Both the British Isles and the Pacific Northwest enjoy such “maritime” climates. Central Asia, the northern Great Plains and Canadian Prairies are classic examples of “continental” climates, which do not benefit from this moderating effect and thus experience bitterly cold winters and blazingly hot summers. The northeastern United States and eastern Canada fall somewhere in between. But because they are under the influence of prevailing winds that blow from west to east, their climate is considerably more continental than maritime.”
I live 4 miles from the sea, not the irish sea, not the atlantic, but the continental north sea which is pretty much unaffected by the gulf stream, and we get far less frost and intense cold than 20 miles inland.
If you want a pocket example of the influence a large body of water can have, I give you Exhibit A: Lake Effect winter weather. If you live within about 30 miles of the southern shores of Lake Erie or Ontario (Cleveland and Buffalo), you can expect to receive about double the snow elsewhere in that state. Winter storms boiling south from Canada across the Great Lakes pick up moisture and dump it as excess precipitation, i.e., snow. For some odd reason, I don’t recall that same effect ever producing bigger than elsewhere thunderstorms during the summer.
and the conclusion of the american scientist paper is that “the large difference in winter temperature between western Europe and eastern North America was caused about equally by the contrast between the maritime climate on one side and the continental climate on the other, and by the large-scale waviness set up by air flow over the Rocky Mountains.” and that we might experience a cooling of about 3 degrees, which would only serve to mitigate the climate warming, rather than produce a little ice age …
well, it feels unusually cool this autumn, and the last 2 winters have been quite different from the previous 2 decades of mild winters …
The whole anthropogenic global warming controversy sometimes looks like “Chicken Little meets the Conspiracy Theorist, round 6”. Scientific factoids along with lots of other decidedly nonscientific stuff get thrown by both sides like weapons, with attempts at a balanced, nonpartisan look few and far between and outshouted. Not that either scientists or politicians have really ever behaved much differently: some of the mathematical and scientific controversies of the past have looked remarkably like the typical internet flamewar. I suspect the nasty politicking mixed with hard science illustrated in Cyteen is not wholly absent from University departments.
I also suspect that the best scientists, those who adopt the rigorously honest “take great care not to fool yourself” attitude Feynman and others have described are probably not to be found on either side of the debate.
My guess is that they’ve throw up their hands in total disgust and gone out to discuss it over a few beers.
I find it ironically amusing to see the theory of global warming espoused as an article of faith or proven beyond all doubt rather than simply being a reasonable explanation of observed correlations between global temperatures and greenhouse gases. I’ll grant you that there are strong correlations and it is likely to be true to at least some extent, but it’s still just a theory. Even Newton’s Laws or Einstein’s theories are not absolutely true. Later developments have found significant deviations under certain circumstances. For instance, Newton’s laws have been shown to be irrelevant in large part at the quantum level. I’m sure that a “rent-a-statistician” could find all sorts of possibly spurious correlations between the observed trends in global temperatures and various measures of development, technology and urbanization that would appear to have only the most tenuous connections to the production of greenhouse gases. Anyone who has lived for a long time west of the mountains in the Pacific Northwest has a fairly jaundiced view of the science of meteorology because our weather is so changeable, strongly affected by the frequently unsettled conditions in the Bering Sea. The new radars have improved things somewhat but we still get daily forecasts that can be way off the mark. I’ll place a lot more credence in their global models that purport to mirror apparently chaotic systems over decades and centuries once they reach 99% reliability worldwide on local 24 hour forecasts. I’m not holding my breath.
Liked your ‘rent-a-statistican’ and whoeheartedly agree on the weather forecasting. We simply don’t know enough about the systems to really know how much of a hiccup humans have caused or what the outcome will be. Although I do like to think this mirrors 800 years ago and we’ll see another mini ice age triggered. Which will posed a whole different set of problems when the growing cycle drops by several weeks a year. We may all end up living in Mexico.
I refused to get too worried about it either and wouldn’t be surprised of instances of ‘when in doubt, manipulate the data’ from either side. But if it does make people finally realize that there is such as thing as finite resources and results in better choices, with large-scale recycling and better care and awareness of the environment as a whole, I’m all for that.
Just because there is a correlation, it does not follow that one has proven causality. A major problem among the innumerate is the supposition that correlation = cause, thus underlying cause and effect are never investigated because the “obvious” truth of a proven correlation blinds us to the fact that we don’t know the root cause
Indeed, for instance one could posit a shift in the distribution of the sun’s spectrum from blue-green wavelengths necessary for photosynthesis to longer wavelengths that carry more of a thermal punch. This could theoretically produce a marked increase in CO2 levels and global temperatures without any consideration of the greenhouse effects. The only thing a correlation tells us is that given a body of data, which may or may not be biased by how, when and where it is collected, two or more values tend to more or less consistently move in the same or opposite directions as one traverses the appropriate axis. One could as easily attribute the increase in greenhouse gases to global warming since correlation and causality are totally different things. The hard part is finding the causal chain and demonstrating how it follows from both the observed data and our understanding of physical laws. Statistics are not “proof” unless one has set up an experiment that demonstrates a novel effect suggested by the theory and one has demonstrated that the chances of this previously unsuspected result having happened by accident rather than following from the theory is statistically nil. IIRC the “red shift” and Lawrence-Fitzgerald contraction served to confirm Einstein’s theory because they were logical extensions of them and the experiments were undertaken afterward, rather than theory serving to explain the original observations. Global warming suffers from the same problems that social “science” theories do, The theories arise from data sampled from chaotic systems that are highly variable unless one artificially biases the data by selecting sources which are far more similar to each other than the population is as a whole. One then develops a theory and supports it by selecting and interpreting data that is not derived from controlled conditions where one can define and measure and qualitatively and quantitavely vary all of the relevant elements of the inputs and outputs. In experiments where many of your inputs are either black box systems or subject to incompletely understood mechanisms, IMHO, the conclusions are as dependent on the experimental design and the selection of dataset or subjects as it is upon the truth or falsity of the proposition in the first place. In those situations, the data tends to be adapted to the terms, definitions and frameworks rather than vice versa. It brings to mind the assertions of the Behavioralists that there is no “free will” while never offering a definition of the term “free will” so that they never had to make a substantive defense of the assertion.
Lies, damn lies, and statistics is an old aphorism, which has been paraphrased, lies, damn lies, and computer simulations. The high incidence of both in AGW arguments looks suspicious to me, even though I lack the mathematical knowledge for a detailed, well informed critique.
Years ago I read an essay on chaotic systems which as I recall it, identified two kinds of randomness in complex systems. One of them is nonlinearity, which sometimes produces damping effects (large difference in cause, small effect) and sometimes chaos (sensitive dependence on initial conditions, or the butterfly effect). There was also dependence on large numbers of independent variables as a source of randomness.
The earth with its oceans, earth, and atmosphere forms a very large and very complex system with nonlinearity of both kinds and considerable randomness, and poorly understood interactions among parts of the system. Factors that seem constant over short time periods are variable over longer ones. I don’t credit the “science is settled” claims, because from what I’ve seen of science (a broad though rather shallow view) our understanding of the various complexities involved just isn’t that good.
I’m certainly in favor of long-term thinking and we should certainly not be fouling our own nest, but hasty political solutions to non-trival engineering and economic problems don’t sound good either.
Amen breth-sistren.
“I’m certainly in favor of long-term thinking and we should certainly not be fouling our own nest, but hasty political solutions to non-trival engineering and economic problems don’t sound good either.”
I agree. Ultimately we should clean up our act because of the one planet bit, but I am more than a little disgusted at the power grabs, politics, and money trails surrounding the whole going green movement. It is an industry now and industries tend to find longevity in “curing” symptoms rather than fixing the problem. See pharmaceuticals or the vitamin craze.
Well, if it does get *too* warm, I know I’ll have to move, because my home city is nearly coastal. That, and I might find I’m a lot less modest about clothing.
Or if it gets colder — I really don’t like sleet and cold. Migrate.
In some support of the climate change affecting global cultures, what about clothing? Or tempers? Or what seem like exaggerations of giant this-or-that in lore?
Are those all merely, “how people were,” even “civilized?”
If your heroes and villains and creatures and food all sound impressive if they are super-sized, but with a warmer climate, might some things grow bigger?
If it’s hotter and you have fewer resources, aren’t you prone to get upset more easily? (Though extra cold could have a similar effect; or would it?)
Clothing. Yes, weaving cloth, tanning skins, and other such are time-consuming, so you might not have as much available. Yes, attitudes toward the body and clothing vary considerably. But overall, wouldn’t a hotter climate tend to mean fewer clothes, while a colder one, more? — over 100*F very long, and even the most devout and modest will consider wearing less. — How testable that is, given that cultures have religious, secular, esthetic, and practical reasons to cover or uncover (or depict it in art or stories), I don’t know, but it seems like the evidence could show or, uh, not show a trend.
Those all may be too dependent on other factors, but could they hold merit if tested?
—–
If the local tribe is too threatened, won’t it migrate or invade or be invaded, and thus undergo major shifts in ideas and language stock and structure and customs? If that is large enough, the language has a more rapid change, and becomes another version or altogether different. If there’s enough data in history or the language itself, might it give clues to the rate of change and to native versus external changes, and thus correlate with known events, climate included?
Written records are likely the only testable data there. Or perhaps I’m being too narrow?
Just throwing out ideas to see what sticks.
In regards to the word ‘theory’, in science it means a logical explanation of observed data. In the case of Climate Change, or Global Warming, the amount of data available is pretty conclusive that something is happening, even if some of the details remain fuzzy (for example temperatures were rising in some areas faster than were predicted by CO emissions, further investigation indicated that this was probably because of a huge increase of particulate emissions from diesel engines).
FYI, I used to work in the emission control industry. I was part of a team designing catalytic converters, and was in constant touch with the Environmental Protection Agency, the California Air Resources Board, and Environment Canada.
Climate Change is a proven fact, even if not all of the details are understood yet.
Wayne
I beg to differ with your semantics, particularly with regard to “theory”,”logic”, “proven” and “fact”. A theory is a plausible chain of logic and causation which explains observed data. One may note that this does not rule out divergent theories which also more or less plausibly explain the data cf. “Big Bang”. A theory becomes accepted when competing theories become implausible and it explains the observed data of novel experiments that are independent of the original observations that gave rise to the theory in the first place. Anything can be proven by logic, it only requires the proper postulates and axioms to drive the conclusions. In fact Aristotelian logic itself requires the most basic axiom of all “A does not equal Not(A)”. The scientific method absolutely depends on the basic assumption that observed data is valid, meaningful and reproducible.
A scientific theory is proven, if and only if, it predicts the results of every relevant experiment exactly within the limits of precision, the measurements are precise enough to be meaningful, and there is no other plausible explanation of the results. In general, this is not possible within the observational sciences because the phenomena being modeled are not reproducible on a meaningful scale in the laboratory and/or some of the inputs are unknown or cannot be either constrained or measured with sufficient precision to rule out any coincidental effects.
Finally, a theory can never be a “fact”. A fact is a datum, or a collection of properties pertaining to a data point, pure and simple. A theory is a logical construct supported more or less by a collection of facts and prior art. The failure to find any dinosaur remains above the K-T boundary is a fact. That this was due to a bolide strike is one theory that attempts to explain that fact. Absolute proof of global warming would require the ability to measure and model every erg of energy and every molecule of air, and the liquids and solids that exchange energy with the air. Of course that level of technology would moot the whole issue since we would certainly be able to control the climate regardless of the concentration of greenhouse gases.
Just remembered an article I wrote last spring which might be of interest, Spring in Canada – Climate Change has it’s Advantages – or Maybe Not.
Wayne
I don’t want to get seriously into the climate debate, but it’s worth pointing a few facts.
‣ The earth is warming up – this is as firmly established as any scientific fact about the weather could possibly be. It’s possible to argue about the reasons for it, but not about the temperature rise itself.
‣Any action creates effects. Human beings have been dumping tens of billions of tons of greenhouse gases into the atmosphere every year, year after year and decade after decade. To imagine that this has no effect is unscientific.
It’s possible to argue about what the nature of the effect is, or how large it is, but it is not possible to argue that human activity has no effect. If volcanoes spewing out ash can effect world climate, then decades of pumping greenhouse gases into the atmosphere can affect world climate.
Actions have consequences.
‣ Large corporations whose industries produce greenhouse gases have a very strong financial interest in preventing any regulation. They are pouring many, many millions of dollars all the time into funding anti-climate-change organizations, creating anti-climate-change talking points, publicizing them through media organizations which are friendly to large corporations, and lobbying governments. These are also facts.
This means that any argument about climate change has to be very carefully and critically examined, and allowance has to be made for the propaganda effort financed by corporations who don’t want to reduce emissions because that would reduce their profits.
I live in the midst of observed fact: it’s called the channeled scablands; and below the melting glaciers of the Cascades. 13000 years ago there was a little ice age: the Younger Dryas—which some think may have resulted from an asteroid impact called the Clovis impact: http://en.wikipedia.org/wiki/Younger_Dryas_event. 12000 years ago, it started to melt.
The ice age melt continued, and has pretty well continued unabated since then. Sea levels began to change 12-13,000 years ago (sunken reefs off Australia) and bigtime, a huge couple of lakes piled up (Lake Missoula, Lake Spokane, and whatever they called the one that flowed down the eastern seaboard.) One fine day all that fresh water roared down the Columbia, the St. Lawrence, the Hudson—in our region, it ripped the surface off the land, exposing old lava flows and leaving ripple patterns so big you need to look at them from an airplane.
The melt has gone on ever since, with little hiccups…not even the aftermath of one of the BIG ice ages, but a bitsy one, and a significant hiccup being the Little Ice Age; possibly one of those pendulum swings in a complex system—or something we haven’t figured yet.
So the Little Ice Age ended, and the Big Slush continues. Personally, I believe pumping the collected carbon output of several geologic ages into the atmosphere over about 100 years has affected the speed of its ending. Seems kind of likely.
Can we reverse it? The biggie is—if we start trying we’re not just kicking a little system in the shins, there’s the bigger critter looming behind it; and beyond that, some really extreme events in the planetary history that make the Younger Dryas look like a kittycat. So what to do?
Ironically, the ice records only go back until the last full melt. They’re good but not complete. We don’t know. What makes me crazy is the people who want to discredit or stop the research as a waste of money or just generally because they don’t like science. I AM a pro-technology sort who believes if tech got us into this mess, intelligent use of tech is the best way to fix it. I do not agree with people who believe if we all go back to the woods and live on berries the earth will fix itself. Didn’t work for the Clovis people, and I don’t think it’s wise now. We’ve got tech. We should use our heads, do the research, and then sit down and figure out whether we should do something or how much we should do. Since it involves the planets whole history, it does take a bit of research, and I think we’ve proved it’s happening. We just need to figure what’s smart to do or not do.
Perhaps the greatest irony is that if someone managed to force us “back to nature”, to a hunter-gatherer society, between the presumed survivors and the 99.99% percent that would have to die to return our population to the levels that the Earth could sustain , we would probably cause the extinction of almost every animal that a man could catch to eat and create new deserts wherever the vegetation even appeared to be edible. Never forget that the neolithic Clovis people were able to hunt all of the megafauna and several other species that survived the Ice Age to extinction.
The Clovis impact hypothesis denies that the Clovis hunters were responsible, and there is the ‘black mat’ layer and embedded iron fragments in mammoth bone which are interesting, in that theory, but certainly I am no fan of early stone age existence as a lifestyle: disease, rule of the nastiest, and venison sushi just do not appeal.
Sorry, but I have to put my 2 cents in here. Neolithic is New Stone Age which correlates to the beginning of domestication — which is Old World applicable, but not really applicable to Clovis period. Also, the jury is still out on humans causing the pleistocene megafauna extinction. Ignoring the probability that folk were in the New World well before the Clovis horizon of about 13,000 years ago, most of the megafauna extinctions seem to correlated to the Younger Dryas, with temps from 5 to 15 degrees Celsius colder than before the onset — and which may have had a much more severe impact on whole populations than what would have been a small amount of folk trying to shoot food. There’s some thought that this sudden, deep cold could have had a major impact on grass and forage growth. Some indicatons in the Southwest [the Black Mat which is currently unexplained, but sure makes me think of bog formations] seem to indicate that it was not only very cold, but extremely wet, which could also affect grass and forage development. It’s also interesting that although Clovis points have been found all over the country, they have a rather limited time span of only about 200 to 300 years of use; the vast majority of them come from back east and in the southeast which seems to have always been forested — and not the sorts of places you’d generally find the typical pleistocene megafauna as we think of them. (But it is were you’d expect to find Solutrian folks who showed up from Europe–but that’s a whole other discussion). I’ve always found it interesting that people seem to forget that the megafauna extinctions was a world-wide event; all the focus is on the New World with all those mammoths and mastodons going away [but the bison doing just fine] — and completely ignores the Old World, with it’s larger population of humans who had been hunting such critters for thousands of years [and leaving some monster kill sites of tens of thousands of animals], but apparently this had no effect whatsoever on the megafauna going extinct. While there are sites where mammoth have been found with Clovis points in the critter, it’s also just as likely that they were hunting deer and snaring lots of bunnies which are much easy to get. I would expect that being involved in a mammoth hunt was a pretty rare thing and may have been more commonly a case of scavenging a dead critter rather than active hunting.
Now, none of this is meant to ignore that humans have been responsible for extinctions from over hunting and other things, but these have been primarily known from closed systems like Australia and Madagascar, and even then, it was over a period of several thousand years [if at all — there’s some new thought on that as well], not on the order of the 200 to 300 years that the Clovis culture existed.
ditto on the venison sushi. Besides, I consider hot running water on demand, indoor toilets and air conditioning a necessity, not a luxury. We should be able to come up with some solutions!